Month: July 2025

Lignans (Phenylpropanoids)

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Lignans (Phenylpropanoids)

Introduction to Lignans (Phenylpropanoids): Lignans (Phenylpropanoid) are dimers linked by β–β’ bonds, found in seeds, fruits, vegetables, and wood. Possess antioxidant, anticancer, and phytoestrogenic properties. Synonyms of Lignans (Phenylpropanoids): Common name: Plant lignans Examples: Sesamin, Podophyllotoxin, Pinoresinol, Secoisolariciresinol Biological Source: Found in Sesamum indicum (sesame seeds), Linum usitatissimum (flaxseeds), Podophyllum hexandrum (mayapple). Family: Varies: Pedaliaceae, … Read more

Introduction to Phenylpropanoids and Flavonoids

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Phenylpropanoids and Flavonoids

Introduction to Phenylpropanoids and Flavonoids: Derived from phenylalanine, vital plant metabolites. Introduction to Phenylpropanoids and Flavonoids are plant-derived secondary metabolites with antioxidant, anti-inflammatory, and antimicrobial properties. General Characteristics: Secondary metabolites derived from phenylalanine, featuring a three-carbon side chain attached to an aromatic ring. Phenylpropanoids: Structure & Diversity: Range from simple cinnamic acid to complex polymers. … Read more

Belladonna

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General Introduction to Belladonna: Belladonna alkaloids are tropane alkaloids recognized for their potent anticholinergic activity. They are used in clinical practice for their mydriatic, antispasmodic, and anti-secretory effects. Synonyms: Common Name: Deadly nightshade alkaloids Scientific Name: Atropa belladonna alkaloids Other Names: Atropine, Hyoscyamine, Scopolamine alkaloids Biological Source: Plant: Derived from the dried leaves and roots … Read more

Parasympathomimetic Agents Classification

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Classification of Parasympathomimetic Agents

Parasympathomimetic agents, also known as cholinergic agonists, are drugs that mimic the action of the parasympathetic nervous system (PNS) by stimulating cholinergic receptors (muscarinic and/or nicotinic). A. Direct-Acting Parasympathomimetic Agents These agents bind directly to cholinergic receptors, mimicking the effect of acetylcholine. Mechanism Act as agonists at muscarinic (and in some cases nicotinic) Not dependent … Read more

Parasympathomimetic Agents

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Parasympathomimetic Agents

Parasympathomimetic agents are drugs that mimic the actions of acetylcholine (ACh) on parasympathetic nervous system These agents stimulate cholinergic receptors, resulting in increased secretions, smooth muscle contraction, slowed heart rate, and other parasympathetic effects. They are classified into two main groups: Direct-acting cholinergic agonists Indirect-acting cholinesterase inhibitors A third category includes cholinesterase reactivators, used to … Read more

Cimetidine

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Cimetidine

Discover how Cimetidine works as an H2 blocker to reduce stomach acid and treat ulcers GERD and related digestive disorders. Structure of Cimetidine It is a first-generation H₂-receptor antagonist featuring a thiazole ring connected to a dimethylamine side chain and an imidazole moiety. Chemical Formula: C₁₆H₂₄N₄S Mode of Action Cimetidine selectively inhibits H₂ receptors on … Read more

H2 Antagonists (H2 Blockers)

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H₂ Antagonists (H₂ Blockers)

This topic describes how H2 antagonists reduce stomach acid by blocking histamine action and are used to treat ulcers acid reflux and related conditions. Definition H2 Antagonists: H₂ antagonists are a class of drugs that block histamine H₂ receptors located on the parietal cells of the stomach. By inhibiting histamine’s action, these drugs reduce the … Read more

Cholinergic receptors

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Cholinergic receptors

Cholinergic receptors are specialized protein receptors located on the surface of cells that bind acetylcholine (ACh), a key neurotransmitter in the autonomic and somatic nervous systems. Acetylcholine acts on two types of receptors: Nicotinic receptors (ionotropic) Muscarinic receptors (metabotropic) Muscarinic Cholinergic receptors Type G-protein-coupled receptors (GPCRs) Subtypes and Signal Pathways Subtype G-protein Pathway Effect M1 … Read more

Cromolyn Sodium

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Cromolyn Sodium

Cromolyn Sodium is a mast cell stabilizer widely used in the treatment of allergic conditions such as asthma, allergic rhinitis, and conjunctivitis. Unlike typical antihistamines, it does not block H₁ receptors directly but works by preventing the release of histamine and other inflammatory mediators from sensitized mast cells. Its unique chemical structure, a polysulfated derivative … Read more

Levocetirizine

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Levocetirizine

Levocetirizine is the active enantiomer of cetirizine, offering enhanced potency and reduced side effects in the treatment of allergic conditions. Structurally, it retains the piperazine ring seen in cetirizine but provides greater selectivity for peripheral H₁ receptors. Structure of Levocetirizine It is the active enantiomer of Cetirizine, featuring a similar piperazine structure with enhanced selectivity. … Read more