title: New sterols with anti-inflammatory potentials against cyclooxygenase-2 and 5-lipoxygenase from Paphia malabarica.
abstract: Marine bivalves occupy a leading share in the total edible molluscs at the coastline regions of south-eastern Asia, and are found to possess significant nutritional and biological potential. Various in vitro evaluation (antioxidant and anti-inflammatory) guided purification of ethyl acetate-methanol (EtOAc-MeOH) extract of bivalve clam, Paphia malabarica characterised two new sterol derivatives as 23-gem-dimethylcholesta-5-en-3β-ol (1) and (22E)-241,242-methyldihomocholest-5,22-dien-3β-ol (2) collected from the south-west coast of Arabian Sea. Their structures were unambiguously assigned on the basis of 1D, 2D NMR spectroscopy and mass spectrometry. The antioxidant and anti-inflammatory activities of 2 as determined by DPPH/ABTS+radical scavenging and anti-cyclooxygenase-2/5-lipoxygenase assays were significantly greater (IC50< 1 mg/mL) than 1 (IC50> 1 mg/mL). Structure-activity relationship analysis revealed that the bioactivities of these compounds were directly proportional to the electronic and lipophilic parameters. This is the first report of the occurrence and characterisation of 23-gem-dimethyl-3β-hydroxy-Δ5-cholestane nucleus and C-30 dihomosterol from marine organisms.
authors.affiliation: a Marine Bioprospecting Section of Marine Biotechnology Division , Central Marine Fisheries Research Institute , Cochin , India.
authors.forename: Minju
authors.initials: M
authors.lastname: Joy
authors.affiliation: a Marine Bioprospecting Section of Marine Biotechnology Division , Central Marine Fisheries Research Institute , Cochin , India.
authors.forename: Kajal
authors.initials: K
authors.lastname: Chakraborty
authors.affiliation: a Marine Bioprospecting Section of Marine Biotechnology Division , Central Marine Fisheries Research Institute , Cochin , India.
authors.forename: Vamshi Krishna
authors.initials: VK
authors.lastname: Raola
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification* / Q000494:pharmacology; D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D001094:Arachidonate 5-Lipoxygenase; D049872:Bivalvia / Q000737:chemistry*; D052246:Cyclooxygenase 2 Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D016859:Lipoxygenase Inhibitors / Q000302:isolation & purification* / Q000493:pharmacokinetics; D013261:Sterols / Q000302:isolation & purification* / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D052246:Cyclooxygenase 2 Inhibitors; D016859:Lipoxygenase Inhibitors; D013261:Sterols; D001094:Arachidonate 5-Lipoxygenase
keywords: (22E)-241,242-methyldihomocholest-5,22-dien-3β-ol; 23-gem-dimethylcholesta-5-en-3β-ol; Bivalve clam; Paphia malabarica; anti-inflammatory activity