title: First report of two new antioxidative meroterpeno 2H-pyranoids from short-necked yellow-foot clam Paphia malabarica (family: Veneridae) with bioactivity against pro-inflammatory cyclooxygenases and lipoxygenase.
abstract: Two new meroterpeno 2H-pyranoids were isolated from the EtOAc:MeOH extract of yellow-foot clam Paphia malabarica. The structures of these newly reported compounds were elucidated based on spectroscopic interpretations. This is the first report of biogenic 2H-pyrans bearing decadienyl and allyloxy-(isopentanyl)-cyclohexene skeletons from marine biota. The extended C18sesquiterpenoid with prenylated irregular farnesene framework was characterised as 2-((E)-deca-1,8-dien-10-yl)-11,12-dihydro-13-propyl-2H-pyran (1). The compound 2, 1'-((10E)-10-(10-(pentan-4-yl)-cyclohex-4-enyl)-allyloxy)-tetrahydro-2',2'-dimethyl-2H-pyran represents the first example of naturally occurring C21prenylated bisabolene-type meroterpenoid, whereas tetrahydro-2',2'-dimethyl-2H-pyran remains attached at C-2' position of rearranged bisabolene framework formed by allyloxy linkage. The antioxidant activities (DPPH/ABTS+) of 1 and 2 were comparable (IC50< 1.0 mg/mL) with α-tocopherol. In addition, these compounds exhibited greater activity against cyclooxygenase-2 than COX-1, and the selectivity indices were significantly lesser (~1.1). No significant differences in anti-5-lipoxygenase activity of 1 and 2 (IC501.02-1.06 mg/mL) than ibuprofen (IC500.93 mg/mL) indicated the potential anti-inflammatory properties of title compounds.
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
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D049872:Bivalvia / Q000737:chemistry*; D051545:Cyclooxygenase 1 / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000187:drug effects; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D016859:Lipoxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011714:Pyrans / Q000737:chemistry / Q000494:pharmacology*; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: C000616915:1'-(10-(10-(pentan-4-yl)cyclohex-4-enyl)allyloxy)-tetrahydro-2',2'-dimethyl-2H-pyran; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D016859:Lipoxygenase Inhibitors; D010851:Picrates; D010936:Plant Extracts; D011714:Pyrans; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2
keywords: Paphia malabarica; anti-inflammatory; antioxidative; cyclooxygenases; lipoxygenase; meroterpeno 2H-pyranoids