title: Two rare antioxidative prenylated terpenoids from loop-root Asiatic mangrove Rhizophora mucronata (Family Rhizophoraceae) and their activity against pro-inflammatory cyclooxygenases and lipoxidase.
abstract: Two new biogenic prenylated terpenoids were isolated from the methanol extract of Rhizophora mucronata. The extended C20sesquiterpenoid with prenylated guaiane framework was characterised as (4E, 8Z)-3, 3a, 6, 7-tetrahydro-3, 9-dimethyl-5-(6-methylheptan-2-yl) cycloocta[b]furan-2-(9aH)-one (1). (35E)-1,2,3,5,6,6-icosahydro-4,4,8b,10,14,17,20,20-octamethylpicen-3-yl-34,35-dimethyloct-31-enoate (2) represents the first example of naturally occurring C40prenylated oleanane-type triterpenoid, whereas one 4,5-dimethyloct-5-enoate side chain remains attached at C-3 position of the oleanane framework formed by the E-ring closure of C30saccharide moiety. The structures of the compounds were elucidated using NMR and mass spectrometric analysis. Compound 1 was found to have significantly greater antioxidant activities (IC50~ 0.75 mg/mL) compared to 2 (IC50> 0.80 mg/mL). No significant differences in anti-cyclooxygenase-2 of these compounds were discernable (IC500.8 - 0.9 mg/mL), whilst compound 1 showed greater anti-5-lipoxidase activities (IC50~ 0.8 mg/mL) those that of 2 (IC500.96 mg/mL). Bioactivities of the prenylated terpenoids were inversely proportional to lipophilic and bulk descriptors.
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
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
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D010936:Plant Extracts / Q000032:analysis; D018517:Plant Roots / Q000737:chemistry; D043982:Rhizophoraceae / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D052246:Cyclooxygenase 2 Inhibitors; D016859:Lipoxygenase Inhibitors; D010936:Plant Extracts; D013729:Terpenes
keywords: Rhizophora mucronata; anti-inflammatory; antioxidant; prenylated terpenoids; structure–activity relationship