Derivative works — US Patent 11358953

The USPTO search results confirm that US Patent 11358953 is titled "Functionalized peptides as antiviral agents" and was issued to Enanta Pharmaceuticals Inc.. The search also confirms the CAFC ruling on June 23, 2026, affirming the invalidity of all claims of US Patent 11,358,953 due to inadequate written description support in the provisional application, which meant it could not claim the earlier priority date and was thus anticipated by Pfizer's prior disclosure of nirmatrelvir in April 2021.

I will now proceed with generating the defensive disclosure document, acknowledging the invalidity of the patent but using its technical content as a basis for broad disclosures to limit future patentability of incremental improvements.

Defensive Disclosure Document for US Patent 11358953

Patent Title: Functionalized peptides as antiviral agents
Patent Number: US11358953
Assignee: Enanta Pharmaceuticals Inc.
Current Legal Status: All claims of US Patent 11358953 have been ruled invalid by the U.S. Court of Appeals for the Federal Circuit (CAFC) as of June 23, 2026, due to anticipation by Pfizer's public disclosure of nirmatrelvir. This disclosure document is generated based on the technical teachings of the invalidated patent to proactively limit future patentability of related innovations by competitors, rendering such improvements obvious or non-novel.

Derivatives of Independent Claim 1: Compound of Formula (I)

Claim 1 describes a compound of Formula (I), and its pharmaceutically acceptable salts, N-oxides, esters and prodrugs. The compound is characterized by various functional groups (A, L1, L2, X, Q, R11, R12, R13, R14, R15, R16) and their allowed variations and substitutions. The core structure involves a series of linked amino acid-like components, including a heterocyclic ring and a terminal group 'X' which can be a nitrile, various carbonyl-containing groups, or other specified functionalities.

Derivative 1.1: Material & Component Substitution – Bioisosteric Replacement of Core Heterocycles

Enabling Description: The indole-based moiety 'A' and the bicyclic proline-like scaffold (formed by L1, L2, and the bridging moiety) can be substituted with various bioisosteric heterocyclic or carbocyclic rings to maintain or alter the electronic, steric, and lipophilic properties critical for 3CLpro binding. For example, the indole ring (A) can be replaced with benzofuran, benzothiophene, pyrrolo[2,3-b]pyridine, pyrazolo[3,4-b]pyridine, or 1H-pyrazolo[3,4-c]pyridine. Similarly, the octahydrocyclopenta[c]pyrrole-1-carboxylate moiety can be replaced with other conformationally constrained bicyclic or tricyclic amino acid derivatives such as 2-azabicyclo[2.2.1]heptane-3-carboxylate, 2-azabicyclo[3.1.0]hexane-3-carboxylate, or 3-azabicyclo[3.1.0]hexane-2-carboxylate, wherein the nitrogen atom is part of the bridging system, and the carboxyl group maintains its relative stereochemistry. The terminal nitrile group (X) can be replaced with other electrophilic warheads like vinyl sulfones, epoxy ketones, or aldehyde hydrates, known to form covalent adducts with cysteine proteases.

graph TD
    A[Original Indole Ring A] -->|Bioisosteric Replacement| B(Benzofuran)
    A --> C(Benzothiophene)
    A --> D(Pyrrolo[2,3-b]pyridine)
    A --> E(Pyrazolo[3,4-b]pyridine)
    F[Original Bicyclic Proline Scaffold] -->|Bioisosteric Replacement| G(2-Azabicyclo[2.2.1]heptane-3-carboxylate)
    F --> H(2-Azabicyclo[3.1.0]hexane-3-carboxylate)
    I[Original Terminal Nitrile X] -->|Electrophilic Warhead Substitution| J(Vinyl Sulfone)
    I --> K(Epoxy Ketone)
    I --> L(Aldehyde Hydrate)

Derivative 1.2: Material & Component Substitution – Non-natural Amino Acid and Peptidomimetic Scaffolds

Enabling Description: The peptide backbone of Formula (I) can be extensively modified to incorporate non-natural amino acids, D-amino acids, β-amino acids, γ-amino acids, or peptidomimetics at various positions (e.g., between the bicyclic core and the terminal X group). For instance, the P2 equivalent position (the amino acid directly preceding the X group) can be replaced with a β-amino acid, specifically β-homoalanine or β-phenylalanine, to alter proteolytic stability and conformational flexibility. Furthermore, the amide linkages within the peptide chain can be replaced with various peptidomimetics, such as reduced amide bonds (—CH2NH—), thiomethylene bonds (—CH2S—), ethylene bonds (—CH2CH2—), or carbamate linkages (—NHCOO—), to enhance metabolic stability or modify pharmacological properties. This extends to cyclic peptide mimetics for increased rigidity.

graph LR
    A[Peptide Backbone] --> B{Amino Acid Modification}
    B --> C[Non-natural AA]
    B --> D[D-Amino Acid]
    B --> E[Beta-Amino Acid]
    B --> F[Gamma-Amino Acid]
    B --> G[Peptidomimetic]
    G --> G1[Reduced Amide]
    G --> G2[Thiomethylene]
    G --> G3[Ethylene]
    G --> G4[Carbamate]
    G --> G5[Cyclic Peptide Mimetic]

Derivative 1.3: Operational Parameter Expansion – Ultra-High Throughput Synthesis and Screening

Enabling Description: The synthesis of compounds of Formula (I) and their derivatives can be adapted for ultra-high-throughput combinatorial chemistry using microfluidic platforms. This involves synthesizing libraries of compounds with variations at A, X, and the peptide linker regions (L1, L2, Q, R groups) on solid supports (e.g., resin beads, peptide microarrays). Subsequent on-bead or on-chip cleavage and direct biochemical screening against 3CLpro can be performed using miniaturized fluorescence resonance energy transfer (FRET) assays or surface plasmon resonance (SPR) in picoliter volumes. Automated liquid handling systems and robotic plate readers operating at speeds of 10^5 to 10^6 assays per day would enable rapid identification of novel inhibitors. Reaction conditions (temperature, pressure, solvent ratios) can be optimized continuously by machine learning algorithms for maximum yield and purity on microscale reactors.

sequenceDiagram
    participant Robot as Robotic Synthesis
    participant MFC as Microfluidic Chip
    participant HTS as HTS Reader
    participant ML as Machine Learning
    Robot->MFC: Dispense Reagents for Library A
    Robot->MFC: Dispense Reagents for Library B
    Note over MFC: On-chip combinatorial synthesis
    MFC->HTS: Transfer cleaved compounds
    HTS->HTS: Perform FRET/SPR assay (pL scale)
    HTS->ML: Send assay results (IC50, Kd)
    ML->Robot: Optimize reaction conditions for next library
    loop Iterative Optimization
        Robot->MFC: Synthesize new library with optimized conditions
        MFC->HTS: Screen compounds
        HTS->ML: Send results
    end

Derivative 1.4: Cross-Domain Application – Agricultural Antiviral Agents

Enabling Description: Compounds derived from Formula (I), particularly those with enhanced environmental stability and systemic uptake in plants, can be repurposed as agricultural antiviral agents. Specifically, the compounds can be formulated as foliar sprays or root drench applications to inhibit plant viral proteases exhibiting structural homology to coronavirus 3CLpro (e.g., potyvirus proteases, comovirus proteases). The 'A' group can be functionalized with specific glycosides or polyethylene glycol chains to improve cuticular penetration and phloem/xylem transport in agricultural crops. The 'X' group can be modified to be photoactivatable or pH-sensitive to enable targeted release within plant tissues upon environmental cues. This approach could protect economically important crops like tomatoes (Tomato Spotted Wilt Virus) or potatoes (Potato Virus Y).

flowchart TD
    A[Compound of Formula (I)] --> B{Formulation}
    B --> C[Foliar Spray]
    B --> D[Root Drench]
    C --> E[Plant Cuticle Penetration]
    D --> F[Root Uptake]
    E --> G[Phloem/Xylem Transport]
    F --> G
    G --> H[Inhibit Plant Viral Protease]
    H --> I[Protect Crop from Viral Infection]
    A -- Functionalization --> J[Glycoside/PEG for Plant Uptake]
    X[Terminal Group X] -- Modification --> K[Photoactivatable/pH-sensitive]

Derivative 1.5: Integration with Emerging Tech – AI-Driven Compound Design and IoT-Monitored Delivery

Enabling Description: Artificial intelligence (AI) can be employed for de novo design and optimization of compounds based on Formula (I). Generative adversarial networks (GANs) or reinforcement learning algorithms can propose novel substitutions for A, X, L1, L2, and the R groups, predicting their 3CLpro inhibitory activity and ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) profiles. This AI-designed compound (or a pharmaceutically acceptable salt thereof) is then integrated into an Internet of Things (IoT)-enabled smart oral delivery system, such as a capsule with embedded micro-sensors. These sensors monitor gastrointestinal pH, temperature, and compound release kinetics in real-time, transmitting data to a patient's smart device or healthcare provider. AI algorithms then adjust subsequent dosing regimens or provide alerts for non-adherence or adverse events based on this real-time pharmacokinetic and pharmacodynamic feedback.

graph TD
    A[AI Drug Design Platform] --> B{Generative AI / ML Algorithms}
    B --> C{Proposed Compound Structures (Formula I Derivatives)}
    C --> D[Predicted Activity & ADMET Profiles]
    D --> E[Synthesized Compound]
    E --> F[IoT-Enabled Smart Oral Delivery System]
    F --> G[Embedded Micro-sensors]
    G --> H{Real-time Data (pH, Temp, Release)}
    H --> I[Wireless Communication (Bluetooth/NFC)]
    I --> J[Patient Smart Device / Cloud]
    J --> K[AI for Dosing Optimization / Alerts]
    K --> F

Derivative 1.6: The "Inverse" or Failure Mode – Diagnostic Prodrug with Controlled Deactivation

Enabling Description: A derivative of Formula (I) can be designed as a diagnostic prodrug for active 3CLpro, where the "X" group is modified into a fluorogenic or chromogenic reporter group. This prodrug is specifically engineered for a controlled deactivation profile, rather than potent and sustained inhibition. Upon cleavage by 3CLpro, it releases a detectable signal, but the resulting cleaved product (lacking the active "X" group) is rapidly metabolized or excreted within minutes, ensuring minimal therapeutic effect or interference with actual antiviral treatments. For example, 'X' could be a cyanocoumarin or nitroaniline moiety, which upon protease cleavage, releases a fluorescent or chromogenic molecule. The rapid deactivation can be achieved by incorporating highly labile ester or amide linkages designed for rapid enzymatic hydrolysis in vivo by non-target enzymes (e.g., esterases), limiting its systemic half-life to under 5 minutes. This creates a transient, high-signal, low-therapeutic-impact diagnostic agent.

stateDiagram-V2
    [*] --> Inactive_Prodrug
    Inactive_Prodrug --> Activated_by_3CLpro : 3CLpro Cleavage
    Activated_by_3CLpro --> Detectable_Signal : Reporter Release
    Detectable_Signal --> Rapid_Metabolism : Non-target Enzyme Hydrolysis
    Rapid_Metabolism --> Excreted_Fragments : Short Half-life (<5min)
    Excreted_Fragments --> [*]

Derivatives of Independent Claim 13: Pharmaceutical Composition

Claim 13 describes a pharmaceutical composition comprising a therapeutically effective amount of the compound of Claim 1 (or any of claims 2-12) and at least one pharmaceutically acceptable carrier or excipient.

Derivative 13.1: Material & Component Substitution – Advanced Nanoparticulate Delivery System

Enabling Description: The pharmaceutical composition can utilize an advanced nanoparticulate delivery system for the compound of Formula (I). This involves encapsulating the active compound within lipid nanoparticles (LNPs), polymeric nanoparticles (PNPs) composed of poly(lactic-co-glycolic acid) (PLGA), or solid lipid nanoparticles (SLNs). These nanoparticles (typically 20-200 nm in diameter) are engineered with surface modifications (e.g., PEGylation, specific targeting ligands for lung epithelial cells) to achieve enhanced solubility, prolonged systemic circulation, reduced immunogenicity, and targeted delivery to respiratory tissues affected by coronavirus infection. The carriers (e.g., PEGylated lipids, PLGA copolymers) would serve as the pharmaceutically acceptable excipients. The active ingredient concentration can range from 0.1% to 20% (w/w) within the nanoparticle core.

classDiagram
    class Pharmaceutical_Composition {
        +Compound_Formula_I active_ingredient
        +Nanoparticle_Carrier excipient
    }
    class Nanoparticle_Carrier {
        +Lipid_Nanoparticle
        +Polymeric_Nanoparticle (PLGA)
        +Solid_Lipid_Nanoparticle
        +Surface_Modification (PEGylation, Ligand)
    }
    class Compound_Formula_I {
        -Formula(I) compound
    }
    Pharmaceutical_Composition --> Compound_Formula_I
    Pharmaceutical_Composition --> Nanoparticle_Carrier

Derivative 13.2: Operational Parameter Expansion – Lyophilized Formulation for Extreme Environmental Stability

Enabling Description: A pharmaceutical composition comprising the compound of Formula (I) can be formulated as a lyophilized powder for reconstitution, designed to withstand extreme storage conditions, such as temperatures ranging from −80°C to +50°C for extended periods. This involves co-lyophilizing the active compound with cryoprotectants and lyoprotectants (e.g., trehalose, mannitol, dextran, human serum albumin) at concentrations of 1-10% (w/w) to preserve protein integrity and prevent degradation during freeze-drying and subsequent storage. The lyophilized cake, with a residual moisture content below 1%, can then be packaged in hermetically sealed vials under inert atmosphere, enabling global distribution and stockpiling without requiring cold chain logistics. Reconstitution with sterile water or saline immediately prior to administration would yield an injectable or oral solution.

flowchart TD
    A[Compound of Formula (I)] --> B[Pre-freeze-dry Solution Prep]
    B --> C{Add Cryoprotectants & Lyoprotectants}
    C --> D[Freeze-drying Process]
    D --> E[Lyophilized Powder (<1% moisture)]
    E --> F[Hermetically Sealed Vial (Inert Atm.)]
    F --> G[Extreme Temp Storage (-80°C to +50°C)]
    G --> H[Reconstitution with Sterile Water/Saline]
    H --> I[Ready for Administration]

Derivative 13.3: Cross-Domain Application – Medicated Feed Additive for Livestock

Enabling Description: A pharmaceutical composition for veterinary use, specifically as a medicated feed additive for livestock (e.g., poultry, swine, cattle) to prevent or treat coronavirus infections. The compound of Formula (I) is microencapsulated within a protective polymer matrix (e.g., zein, ethylcellulose) to ensure stability during feed processing and passage through the animal's digestive tract. The microcapsules, with diameters between 50-500 microns, are then blended into animal feed at a therapeutically effective concentration (e.g., 10-100 ppm, w/w). The composition would include palatable excipients and binders suitable for animal consumption, such as corn starch, soy meal, and flavorants. This provides a systemic delivery of the antiviral agent through dietary intake.

graph TD
    A[Compound of Formula (I)] --> B[Microencapsulation]
    B --> C[Protective Polymer Matrix (Zein, Ethylcellulose)]
    C --> D[Microcapsules (50-500um)]
    D --> E[Blend with Feed Ingredients]
    E --> F[Medicated Feed Additive (10-100ppm)]
    F --> G[Administer to Livestock]
    G --> H[Systemic Antiviral Action]

Derivative 13.4: Integration with Emerging Tech – 3D-Printed Personalized Dosage Forms

Enabling Description: The pharmaceutical composition can be manufactured as 3D-printed personalized dosage forms, such as tablets or oral films, tailored to individual patient needs. Utilizing fused deposition modeling (FDM) or stereolithography (SLA) techniques, the active compound of Formula (I) is incorporated into a pharmaceutical ink or filament comprising excipients like polyvinyl alcohol, hydroxypropyl methylcellulose, and polyethylene oxide. Real-time patient data (e.g., weight, comorbidities, genetic markers obtained from electronic health records or wearable IoT sensors) can be fed into an AI algorithm that calculates the precise dose and release profile. The 3D printer then fabricates a solid dosage form with customized drug loading (e.g., 1 mg to 500 mg) and programmed dissolution kinetics (e.g., immediate release, sustained release over 12 hours) by varying the infill density or geometry of the print. This ensures optimal therapeutic outcomes and minimizes adverse effects.

flowchart TD
    A[Patient Data (EHR, IoT Sensors)] --> B[AI Dosing Algorithm]
    B --> C{Customized Dose & Release Profile}
    C --> D[Pharmaceutical Ink/Filament Preparation]
    D --> E[3D Printing Machine (FDM/SLA)]
    E --> F[Personalized Dosage Form]
    F --> G[Patient Administration]

Derivative 13.5: The "Inverse" or Failure Mode – Deactivatable/Neutralizing Topical Gel

Enabling Description: A pharmaceutical composition designed for safe failure or deactivation, specifically a topical gel for nasal or oral application containing a compound of Formula (I) derivative. This derivative is designed to be highly potent in vitro but rapidly deactivated or neutralized in vivo upon exposure to specific physiological conditions (e.g., high pH in the gut, specific enzyme activity in blood plasma) if inadvertently ingested or absorbed systemically. The gel matrix comprises pH-sensitive polymers (e.g., Carbopol, poloxamers) that ensure localized release in the nasal/oral cavity (pH 5.5-7.0) but rapid degradation upon reaching the stomach (pH 1-3) or blood (pH 7.4). This ensures that while it functions as a localized antiviral barrier, any systemic absorption leads to its rapid deactivation, preventing unintended systemic pharmacological effects. The primary excipients would facilitate topical adherence and controlled release.

stateDiagram-V2
    [*] --> Topical_Gel_Formulation
    Topical_Gel_Formulation --> Local_Release : Nasal/Oral Cavity (pH 5.5-7.0)
    Local_Release --> Antiviral_Action : Local Inhibition of Coronavirus
    Topical_Gel_Formulation --> Inadvertent_Ingestion : If Swallowed
    Inadvertent_Ingestion --> Rapid_Deactivation : Stomach (pH 1-3) / Plasma (Enzymes)
    Rapid_Deactivation --> Neutralized_Compound : Loss of Activity
    Neutralized_Compound --> Excretion : Safe Clearance

Derivatives of Independent Claim 14: Method for Treating or Preventing a Coronavirus Infection

Claim 14 outlines a method for treating or preventing a coronavirus infection in a subject, comprising administering to the subject a therapeutically effective amount of a compound of Claim 1 (or any of claims 2-12).

Derivative 14.1: Material & Component Substitution – Nebulized Inhalation of Microparticles

Enabling Description: The method of treating a coronavirus infection involves administering the compound of Formula (I) via nebulized inhalation of dry powder microparticles. The compound is micronized to a respirable particle size (1-5 microns) and co-formulated with a pharmaceutically acceptable excipient such as lactose or mannitol. This dry powder blend is loaded into a single-dose or multi-dose dry powder inhaler (DPI) device. The patient inhales the microparticles, ensuring direct deposition of the active compound into the bronchioles and alveoli, maximizing local drug concentration in the lung tissue while minimizing systemic exposure. This method is particularly effective for respiratory viral infections like COVID-19.

flowchart TD
    A[Compound of Formula (I)] --> B[Micronization (1-5um)]
    B --> C[Co-formulate with Lactose/Mannitol]
    C --> D[Dry Powder Blend]
    D --> E[Load into Dry Powder Inhaler (DPI)]
    E --> F[Patient Inhalation]
    F --> G[Pulmonary Deposition (Bronchioles, Alveoli)]
    G --> H[Local Antiviral Action in Lungs]

Derivative 14.2: Operational Parameter Expansion – Pre-exposure Prophylaxis (PrEP) in High-Risk Populations

Enabling Description: A method for preventing coronavirus infection through pre-exposure prophylaxis (PrEP) in high-risk populations (e.g., healthcare workers, immunocompromised individuals, household contacts of infected persons). A lower, sub-therapeutic dose of the compound of Formula (I) is administered orally once daily or weekly, starting at least 24-48 hours prior to anticipated exposure and continuing for the duration of risk. The dosage is carefully titrated to maintain prophylactic concentrations in target tissues (e.g., respiratory mucosa) without inducing significant systemic side effects. This method shifts the operational paradigm from treatment to preventative intervention, targeting individuals before active infection.

sequenceDiagram
    participant Patient as High-Risk Patient
    participant Compound as Compound (Formula I)
    Patient->>Compound: Administer Low-Dose (e.g., daily/weekly)
    Note over Patient,Compound: Starts 24-48h prior to exposure
    Patient->>Patient: Monitors Exposure Risk
    loop During Risk Period
        Patient->>Compound: Continue Administration
    end
    Compound->>Patient: Maintains Prophylactic Concentration
    Compound->>Patient: Prevents Viral Entry/Replication upon Exposure

Derivative 14.3: Cross-Domain Application – Wildlife Population Control of Viral Outbreaks

Enabling Description: A method for controlling coronavirus outbreaks in wild animal populations (e.g., bats, civets, mink farms) that act as natural reservoirs or intermediate hosts. The compound of Formula (I) is incorporated into palatable bait formulations (e.g., vaccine-laced baits, medicated feed blocks) designed for consumption by specific wildlife species. These baits are deployed in targeted areas using remote dispensing systems to ensure uptake. The method involves administering a therapeutically effective dose to a sufficient proportion of the animal population to reduce viral shedding and interrupt transmission chains, thereby preventing zoonotic spillover events or mitigating ecological impact. This method requires considerations for environmental impact and non-target species.

flowchart LR
    A[Compound of Formula (I)] --> B[Palatable Bait Formulation]
    B --> C[Remote Bait Dispensing System]
    C --> D[Targeted Wildlife Area Deployment]
    D --> E[Consumption by Wildlife Population]
    E --> F{Therapeutic Dose Reached?}
    F -- Yes --> G[Reduced Viral Shedding]
    F -- No --> D
    G --> H[Interrupt Transmission Chains]
    H --> I[Prevent Zoonotic Spillover/Mitigate Outbreak]

Derivative 14.4: Integration with Emerging Tech – Blockchain-Enabled Clinical Trial Management

Enabling Description: The method of treating a coronavirus infection using compounds of Formula (I) is managed through a blockchain-enabled clinical trial system. Patient enrollment, consent, drug dispensing, administration records, adverse event reporting, and clinical outcome data are securely recorded as immutable transactions on a distributed ledger. IoT sensors (e.g., wearable biometric devices, smart pill bottles) automatically log drug adherence and physiological responses, with data encrypted and time-stamped on the blockchain. Smart contracts automate data sharing with regulatory bodies and ensure compliance with ethical guidelines, while maintaining patient privacy through pseudonymization. This provides transparent, auditable, and secure management of large-scale clinical trials for novel antiviral therapies.

sequenceDiagram
    participant Patient as Patient (IoT Devices)
    participant EHR as Electronic Health Record
    participant Researcher as Clinical Researcher
    participant Pharma as Pharmaceutical Company
    participant Regulator as Regulatory Authority
    Patient->>EHR: Biometric Data
    Researcher->>Blockchain: Enroll Patient, Consent (Smart Contract)
    Pharma->>Blockchain: Dispense Compound (Formula I) (Immutable Record)
    Patient->>Blockchain: Drug Adherence (IoT Pill Bottle), AE Reporting
    Researcher->>Blockchain: Log Clinical Outcomes
    Blockchain->>Regulator: Automated Data Sharing (Smart Contract)
    Note over Patient,Regulator: Secure, Immutable, Transparent Data

Derivative 14.5: The "Inverse" or Failure Mode – Viral Fitness Reversion Induction

Enabling Description: A method designed not to directly inhibit viral replication, but to induce a "failure mode" in the virus itself, leading to reversion to a less virulent or non-replicative state. This involves administering a compound of Formula (I) derivative that acts as a weak, non-competitive antagonist of 3CLpro, or preferentially binds to an allosteric site. Instead of direct inhibition, this derivative induces conformational changes in 3CLpro that promote error-prone replication or processing of the viral polyprotein. The goal is to drive the virus towards genetic drift leading to loss-of-function mutations or replication incompetence, rather than direct viral clearance. This would be a subtle, evolutionary pressure rather than a direct killing mechanism, potentially useful in preventing the emergence of highly drug-resistant strains by promoting less fit variants.

flowchart TD
    A[Compound of Formula (I) Derivative] --> B[Weak 3CLpro Antagonist]
    B --> C{Allosteric Binding / Conformational Change}
    C --> D[Induced Error-prone Viral Replication]
    C --> E[Impaired Polyprotein Processing]
    D --> F[Loss-of-Function Mutations]
    E --> F
    F --> G[Viral Replication Incompetence / Reduced Virulence]
    G --> H[Controlled Viral Clearance / Attenuation]

Derivatives of Independent Claim 22: Method of Inhibiting Coronavirus 3C-Like Protease Activity

Claim 22 specifies a method of inhibiting coronavirus 3C-Like protease (3CLpro) activity, involving contacting the 3CLpro with a therapeutically effective amount of a compound of Claim 1 (or any of claims 2-12).

Derivative 22.1: Material & Component Substitution – Label-Free Biosensor Assay

Enabling Description: The method of inhibiting coronavirus 3CLpro activity is performed using a label-free biosensor assay. Instead of fluorescence-based detection, surface plasmon resonance (SPR) or bio-layer interferometry (BLI) biosensors are utilized. Recombinant 3CLpro is immobilized onto the biosensor surface. Compounds of Formula (I) are flowed over the surface, and their binding affinity (Kd) and kinetic parameters (kon, koff) to the immobilized protease are measured directly without the need for labeled substrates. This provides a quantitative and label-free assessment of enzyme-inhibitor interaction, allowing for characterization of binding mechanisms, including competitive, non-competitive, and uncompetitive inhibition, and is compatible with high-throughput screening of a compound library.

sequenceDiagram
    participant Recombinant_3CLpro as Recombinant 3CLpro
    participant Biosensor as SPR/BLI Biosensor
    participant Compound_Formula_I as Compound (Formula I)
    Recombinant_3CLpro->>Biosensor: Immobilize 3CLpro on surface
    Biosensor->>Compound_Formula_I: Flow Compound over surface
    Biosensor->>Biosensor: Measure Real-time Binding Response
    Biosensor->>Data_Analysis: Extract Kd, kon, koff
    Data_Analysis->>Results: Quantify 3CLpro Inhibition Activity

Derivative 22.2: Operational Parameter Expansion – Extremophilic Viral Protease Inhibition

Enabling Description: A method for inhibiting 3CLpro activity of extremophilic coronaviruses or their analogs, such as those adapted to high-temperature (thermophilic) or high-salinity environments. The assay is conducted at elevated temperatures (e.g., 50°C-95°C) or high salt concentrations (e.g., 1-3 M NaCl) to mimic the native conditions of such hypothetical extremophilic viruses. Compounds of Formula (I) with enhanced thermal stability or salt tolerance are synthesized (e.g., by incorporating fluorine atoms, specific ring constraints, or non-natural amino acids known to confer stability). The method identifies inhibitors active under these extreme conditions, expanding the applicability to diverse viral threats or industrial enzyme inhibition.

flowchart TD
    A[Compound of Formula (I) (Thermally Stable Derivative)] --> B[Recombinant Extremophilic 3CLpro]
    C[Assay Buffer (High Temp/High Salinity)]
    A & B & C --> D{Incubation at Extreme Conditions}
    D --> E[Measure 3CLpro Activity]
    E --> F[Assess Inhibition Efficacy]

Derivative 22.3: Cross-Domain Application – Biocatalytic Protease Regulation in Industrial Processes

Enabling Description: The method of inhibiting protease activity is applied in an industrial biocatalytic process, where a 3CLpro-like enzyme (e.g., a process impurity, an unwanted side-reaction catalyst, or an enzyme requiring precise regulation) is present. Compounds of Formula (I) are utilized as specific enzyme inhibitors to finely tune the activity of this protease in bioreactors. For example, in a fermentation process for peptide synthesis, an undesired protease (with structural homology to 3CLpro) might degrade the product. Administering a compound of Formula (I) derivative to the bioreactor system (e.g., via controlled release polymer beads) at concentrations sufficient to inhibit the unwanted protease ensures higher yields of the desired product. The method allows for precise control of enzymatic degradation in industrial biotechnology.

flowchart LR
    A[Industrial Bioreactor] --> B[Biocatalytic Process]
    B --> C[Target Product]
    B --> D[Unwanted Protease Activity]
    D --> E[Product Degradation]
    X[Compound of Formula (I) Derivative] --> F[Controlled Release Polymer Beads]
    F --> A
    A -->|Inhibits| D
    D --> G[Reduced Product Degradation]
    G --> H[Increased Target Product Yield]

Derivative 22.4: Integration with Emerging Tech – Quantum Computing-Assisted Drug Discovery

Enabling Description: The method for inhibiting coronavirus 3CLpro activity is enhanced by quantum computing for accelerated drug discovery. High-fidelity quantum simulations are performed to predict the binding energies and conformational dynamics of novel compounds of Formula (I) with 3CLpro, far exceeding classical computational capabilities. Quantum algorithms (e.g., variational quantum eigensolver, quantum approximate optimization algorithm) are used to screen vast chemical spaces for optimal substitutions on A, X, and the various R groups, predicting favorable interaction energies with the protease active site. This allows for the in silico identification of ultra-potent inhibitors before laborious chemical synthesis, drastically reducing the time and resources required for lead compound optimization and experimental validation.

sequenceDiagram
    participant Quantum_Computer as Quantum Computer
    participant 3CLpro_Model as 3CLpro Protein Model
    participant Compound_Library as Formula I Compound Library (Virtual)
    participant Lead_Selection as Lead Compound Selection
    Compound_Library->>Quantum_Computer: Input Molecular Data (Formula I variations)
    3CLpro_Model->>Quantum_Computer: Input Protease Active Site Data
    Quantum_Computer->>Quantum_Computer: Run Quantum Simulations (Binding Energy, Dynamics)
    Quantum_Computer->>Lead_Selection: Output Optimized Binding Candidates
    Lead_Selection->>Experimental_Validation: Synthesize & Test Top Candidates

Derivative 22.5: The "Inverse" or Failure Mode – Protease Activity Enhancement/Stabilization

Enabling Description: A method for enhancing or stabilizing 3CLpro activity, rather than inhibiting it. This involves contacting 3CLpro with a compound of Formula (I) derivative designed to act as a positive allosteric modulator or a chemical chaperone. This derivative binds to a site distant from the active site, inducing conformational changes that increase the enzyme's catalytic efficiency (kcat) or improve its thermal stability. This "inverse" approach could be useful for research applications, such as improving recombinant 3CLpro yield or activity in biochemical assays, or for developing therapeutic strategies that require controlled protease activation (e.g., in protein processing disorders where a related protease is underactive). The derivative would lack the typical electrophilic warhead of an inhibitor and instead contain motifs that promote stabilizing interactions.

stateDiagram-V2
    [*] --> Inactive_or_Low_Activity_3CLpro
    Inactive_or_Low_Activity_3CLpro --> Compound_Binding : Positive Allosteric Modulator
    Compound_Binding --> Active_or_Stable_3CLpro : Conformational Change / Stabilization
    Active_or_Stable_3CLpro --> Enhanced_Catalytic_Efficiency
    Active_or_Stable_3CLpro --> Increased_Thermal_Stability

Derivatives of Independent Claim 23: Method for Treating a Respiratory Disorder

Claim 23 describes a method for treating a respiratory disorder in a subject, comprising administering to the subject a therapeutically effective amount of a compound of Claim 1 (or any of claims 2-12).

Derivative 23.1: Material & Component Substitution – Smart Inhaler with Integrated Biosensors

Enabling Description: The method of treating a respiratory disorder exacerbated by coronavirus infection involves administering the compound of Formula (I) via a "smart" inhaler. This inhaler incorporates integrated biosensors that measure key respiratory biomarkers (e.g., exhaled nitric oxide, peak expiratory flow, spirometry) and wirelessly transmits this data to a connected application on a patient's smartphone. The active compound (e.g., a dry powder formulation) is delivered through the inhaler, and the biosensor data provides real-time feedback on lung function. The excipients for the inhaled formulation would be standard carriers like lactose or mannitol, enabling consistent drug delivery.

flowchart TD
    A[Patient with Respiratory Disorder] --> B[Smart Inhaler]
    B --> C[Integrated Biosensors]
    C --> D{Measure Exhaled NO, PEF, Spirometry}
    D --> E[Wireless Data Transmission]
    E --> F[Patient Smartphone App]
    F --> G[Cloud Healthcare Platform]
    B --> H[Deliver Compound of Formula (I) (Dry Powder)]
    H --> I[Lung Delivery]
    G --> J[Physician Monitoring / AI-driven Recommendations]

Derivative 23.2: Operational Parameter Expansion – Aerosolized Therapy for Neonatal/Pediatric Respiratory Distress Syndrome

Enabling Description: A method for treating respiratory distress syndrome (RDS) in neonates or young pediatric patients, when complicated by coronavirus infection. The compound of Formula (I) is formulated as a finely atomized aerosol solution (e.g., 0.9% saline solution with a surfactant) delivered via specialized neonatal nebulizers (e.g., vibrating mesh nebulizers) or during mechanical ventilation. The low-volume, high-concentration aerosol ensures efficient drug delivery to the delicate lung tissues of infants, minimizing systemic exposure. Dosages are carefully scaled based on body weight (e.g., 0.01 mg/kg to 0.1 mg/kg) and administered frequently (e.g., every 4-6 hours) to maintain therapeutic concentrations while accounting for rapid clearance rates in this vulnerable population.

flowchart TD
    A[Neonatal/Pediatric RDS with Coronavirus] --> B[Compound of Formula (I) (Aerosolized)]
    B --> C[Specialized Neonatal Nebulizer / Ventilator]
    C --> D[Finely Atomized Aerosol (Surfactant)]
    D --> E[Direct Lung Delivery (Infant)]
    E --> F[Therapeutic Action in Lung Tissue]
    F --> G[Improved Respiratory Function]

Derivative 23.3: Cross-Domain Application – Bioremediation of Airborne Viral Contaminants

Enabling Description: A method for the bioremediation of airborne viral contaminants, including coronaviruses, in enclosed environments (e.g., HVAC systems, public transportation, cleanrooms). The compound of Formula (I) is aerosolized into the air (e.g., via specialized humidifiers or HVAC filters coated with the compound) at concentrations below human toxicity levels but sufficient to contact and inhibit the 3CLpro of airborne viral particles. The compound acts as an airborne antiviral "scrubber," neutralizing viral infectivity in the air. This non-biological approach complements traditional air filtration, actively degrading viral components rather than just capturing them, thereby reducing the risk of transmission in high-traffic indoor spaces.

flowchart TD
    A[Enclosed Environment (e.g., HVAC)] --> B[Airborne Viral Contaminants (Coronavirus)]
    C[Compound of Formula (I) (Aerosolized / Filter Coated)]
    C --> A
    A --> D{Contact with Viral Particles}
    D --> E[Inhibition of Viral 3CLpro]
    E --> F[Neutralized Viral Infectivity]
    F --> G[Reduced Airborne Transmission Risk]

Derivative 23.4: Integration with Emerging Tech – AI-Optimized Personalized Ventilator Management

Enabling Description: A method for treating severe respiratory disorder in intubated patients with coronavirus infection, using an AI-optimized personalized ventilator management system. The compound of Formula (I) is administered systemically (e.g., continuous intravenous infusion) or locally (e.g., aerosolized via ventilator circuit). Real-time physiological data from the patient (e.g., continuous blood gas analysis, lung mechanics, hemodynamic parameters) is fed into an AI algorithm. This AI continuously analyzes the data to adjust ventilator settings (e.g., PEEP, tidal volume, respiratory rate) and titrate drug infusion rates to optimize oxygenation, minimize lung injury, and enhance the efficacy of the antiviral compound. This adaptive approach ensures patient-specific care, responding dynamically to changes in the respiratory status and drug effect.

sequenceDiagram
    participant Patient as Intubated Patient
    participant Compound as Compound (Formula I)
    participant Ventilator as Mechanical Ventilator
    participant Biosensors as Physiological Biosensors
    participant AI_System as AI Optimization System
    Compound->>Patient: Administer (IV/Aerosol)
    Biosensors->>Patient: Collect Real-time Data (Blood Gas, Lung Mechanics)
    Patient->>Biosensors: Physiological Response
    Biosensors->>AI_System: Transmit Data
    AI_System->>AI_System: Analyze Data, Optimize Parameters
    AI_System->>Ventilator: Adjust Ventilator Settings
    AI_System->>Compound: Adjust Drug Infusion Rate
    loop Continuous Optimization
        Biosensors->>AI_System: Updated Data
        AI_System->>Ventilator: Further Adjustments
        AI_System->>Compound: Further Adjustments
    end

Derivative 23.5: The "Inverse" or Failure Mode – Respiratory Symptom Mimicry for Diagnostic Challenge

Enabling Description: A method designed to induce transient, mild respiratory symptoms (e.g., cough, slight congestion, mild dyspnea) in a controlled environment, mimicking early-stage viral respiratory disorder, for the purpose of challenging and validating novel diagnostic tools or personal protective equipment (PPE). A compound of Formula (I) derivative that has no antiviral activity but is a weak irritant to respiratory mucosa (e.g., modified to include a mildly irritating functional group or formulated with a non-toxic irritant) is administered via a sub-aerosolized mist in a controlled chamber. The induced symptoms would be self-limiting and resolve within minutes, without viral infection. This provides a safe, non-infectious "failure mode" simulation of a respiratory illness for R&D purposes, without involving actual pathogens.

stateDiagram-V2
    [*] --> Compound_Derivative_Preparation
    Compound_Derivative_Preparation --> Sub_Aerosolized_Mist : Administer to Test Subject
    Sub_Aerosolized_Mist --> Transient_Mild_Symptoms : Mimic Early Viral Symptoms
    Transient_Mild_Symptoms --> Diagnostic_Tool_Challenge : Test Sensitivity/Specificity
    Transient_Mild_Symptoms --> PPE_Validation : Test Filtration Efficiency
    Transient_Mild_Symptoms --> Self_Limiting_Resolution : Within Minutes (No Pathogen)
    Self_Limiting_Resolution --> [*]

Combination Prior Art Scenarios with Open-Source Standards

Here are three scenarios where the teachings of US Patent 11358953 (specifically the concept of functionalized peptides as antiviral agents targeting 3CLpro) could be combined with existing open-source standards to render future incremental improvements obvious or non-novel.

Scenario 1: Combination with Open-Source Cheminformatics Libraries for Structure-Activity Relationship (SAR) Studies

Open-Source Standard: RDKit (a collection of cheminformatics and machine-learning software written in C++ and Python, released under the BSD license), Open Babel (a chemical toolbox designed to speak the many languages of chemical data), or PubChem (open chemistry database at NCBI).
Enabling Description: The compounds of Formula (I) from US11358953, known for their 3CLpro inhibitory activity, can be subjected to extensive in silico structure-activity relationship (SAR) studies using open-source cheminformatics libraries such as RDKit and Open Babel. These tools enable the generation of molecular descriptors (e.g., topological polar surface area, logP, number of rotatable bonds), pharmacophore models, and similarity searches against public databases like PubChem. A person skilled in the art, combining the disclosed scaffold of Formula (I) with these readily available open-source tools, would find it obvious to systematically explore variations of R-groups, linkers, and terminal functionalities (A, X, R11-R16) to optimize potency, selectivity, and ADMET properties. For example, RDKit's molecular fingerprinting and substructure searching capabilities would facilitate the identification of novel bioisosteric replacements for 'A' or 'X' within the existing chemical space, making subsequent patenting of such derivatives non-novel.

Scenario 2: Combination with Open-Source Protein Structure Prediction and Docking Software

Open-Source Standard: AlphaFold (deep learning system for protein structure prediction), Rosetta (software suite for macromolecular modeling, prediction, and design), AutoDock Vina (fast and accurate docking tool), or PyRx (virtual screening software).
Enabling Description: The known crystal structure of coronavirus 3CLpro (e.g., from SARS-CoV-2, available in the Protein Data Bank (PDB) as an open-source resource), when combined with open-source protein structure prediction (like AlphaFold for refining loop regions or understanding conformational flexibility) and molecular docking software (like AutoDock Vina or PyRx), renders obvious the design of novel 3CLpro inhibitors based on the scaffold of Formula (I) from US11358953. A person skilled in the art would use these tools to virtually screen libraries of compounds derived from Formula (I) (e.g., with variations in 'A', 'X', and R-groups) against the 3CLpro active site. The software predicts binding poses and affinities, guiding the rational design of inhibitors with improved interactions (e.g., hydrogen bonding, hydrophobic interactions) with key active site residues. This systematic computational approach, facilitated by open-source tools and public protein data, would make any minor structural modifications to the disclosed peptides for improved binding non-novel.

Scenario 3: Combination with Open-Source Electronic Health Record (EHR) Standards and Telemedicine Protocols

Open-Source Standard: HL7 FHIR (Fast Healthcare Interoperability Resources - a standard for exchanging healthcare information electronically), OpenEMR (open-source electronic health records and practice management solution), or DICOM (Digital Imaging and Communications in Medicine - standard for handling, storing, printing, and transmitting medical imaging information).
Enabling Description: The method of treating a coronavirus infection (Claim 14) using compounds of Formula (I) can be readily combined with existing open-source EHR standards and telemedicine protocols to optimize patient management and drug efficacy. Using HL7 FHIR, a patient's medical history, co-medications, viral load, and adverse event profiles can be securely shared and integrated across different healthcare providers and systems. Telemedicine platforms (utilizing open communication standards) would enable remote monitoring of patients receiving the compound of Formula (I), allowing for dose adjustments or symptom management without in-person visits. This combination makes it obvious to implement personalized treatment regimens, track real-world effectiveness, and manage drug interactions for patients receiving these antiviral agents. The integration of such an antiviral therapy into standard digital healthcare workflows for improved patient outcomes is a straightforward application of existing open technologies.