Chemical Constituents And Antioxidant Activity Of Hypocotyls Of Mangrove Bruguiera Gymnorrhiza

The resource of mangrove in Guangxi Province is really abundant. Mangrove Bruguiera gymnorrhiza belongs Rhizophoraceae, the gene of Bruguiera. And the hypocotyls of B. gymnorrhiza usually used to medicine and food in the coastal resident. The B. gymnorrhiza survives in the intersection of marine and land so that compounds from B. gymnorrhiza have the character of new structure、significant bioactivity and eco-friendly. For searching the new natural antioxidant and rationally developing the resource of mangrove, this research made a investigation about chemical constitutions and antioxidant activity of hypocotyl of B. gymnorrhiza.Twenty-eight compounds were isolated from the fresh hypocotyls of B. gymnorrhiza through by column chromatography on silica gel and HPLC. Compounds obtained from the EtOAc fraction and n-BuOH of ethanol extract were eighteen and ten, respectively. The structures of twenty-seven compounds were determined by spectroscopic analysis and compared to the literature data. Including four Cyanogenic glycosides:menisdaurin (H25)、Menisdaurin A (H26)、Menisdaurin B (H27)、Menisdaurin C (H28); three Flavonoids:5,7,2’,5’-tetrahydroxy-(2R,3R)-flavan-3-ol (H13)、Gossypetin-16-rutinoside (H17)、quercetin-3-rutinoside (H18); twoiridoids:vomifoliol roseoside Ⅱ (H16); five Akaloids:Gymnorrhizin A (H4)、Gymnorrhizin B (H6)、Gymnorrhizin C (H8)、1,3-dimethyluracil (H20)、3-methyluridine (H24); three ketones:menisdaurillide (H2)、aquilegiolide (H3)、 Gymnorrhizin D(H9); three Sterols:cholestero(H1)、3-β-(Z)-coumaroyllupeol (H22)、dioslupecin (H23); four Aromatic esters:methyl caffeate (H5)、 protoeatechuie acid methyl ester (H14)、dibutyl phthdate (H19)、 bis(2-ethylhexyl)phthalate(H21); three Aromatic acids:4-hydroxybenzoic acid (H10)、3-hydroxy-4-methoxybenzoic acid(Hll)、4-methoxyphenylacetic acid (H15).Among them, H4、H6、H8、H9、H17、H26、H27、H28were new compounds.The antioxidant activity of eight new compounds were evaluated by HepG2cell-based antioxidant assays(CAA). Among them, H17shows the hightest antioxidant activity with value of CAA112.54μmolQE/100μmol. Coming the H26(46.43pmolQE/100μmol)、H28(27.00μmolQE/100μmol)、 H27(6.50μmolQE/100μmol), show moderate antioxidant activity. H4、H6、 H8、H9did not show any antioxidant activity.Besides, the antioxidant compounds derived from marine organism were summarized.