Studies On Chemical Constituents Of Mangrove Plant Aegiceras Corniculatum

Mangroves are open ecosystems that straddle the land and the sea, from freshwater to seawater, often with distinct zone of plant, animal and microorganism. Mangrove plants are closely linked with the adjacent landward catchment and the seaward marine system. In order to search for new bioactive natural products from mangrove plants, we systematically examined the chemical constituents of Aegiceras corniculatum.Twenty compounds were isolated from the petroleum ether extract of A. corniculatum by column chromatography and their structures were elucidated by means of spectral analysis. Their structures are named 2-hydroxy-5-methoxy-3-nonyl-1,4-benzoquinone (1),5-O-methylembelin (2),5-O-methyl-rapanone(3),2-hydroxy-5-ethoxy-3-nonyl-1,4-benzoquinone(4*), 5-O-ethylembelin (5),2,5-dihydroxy-6-methyl-3-n-nonyl-1,4-benzoquinone (6), 2,5-dihydroxy-6-methyl-3-undecyl-1,4-benzoquinone (7),2,5-dihydroxy-6-methyl-3-tridecyl-1,4-benzoquinone (8),2,5-dihydroxy-6-methyl-3-pentadecyl-1,4-benzoquinone (9*),5-O-butyl-embelin (10*),2-dodecanoyl-4-hydroxy-4H-3-carboxylate (11*),3,7-dihydroxy-2,5-diundecylnaphthoquinone(12), 2-((7S)-3-hydroxy-3,7,11,15-tetramethylhexadecyl)-3,5,6-trimethylbenzene-1,4-diol(13), (E)-icos-6-enoic acid(14), diisobutyl phthalate (15), dibutyl phthalate (16), diisopentyl phthalated (17), bis(7-methyloctyl) (18), stigmasterol (19), taraxerol (20). Among them, compound 4, 9, 10, 11 are novel skeleton compounds. The structural patterns included benzoquinones (1-10*), cycloalkenes (11*), naphthoquinone (12), hydroxybenzene (13), fatty acids (14), benzoic acid derivatives (15-18), steroid (19), and triterpenoid (20).Four novel compounds were isolated and identified from the mangrove plant A. corniculatum.. Among them, compound 11 was a novel skeleton compound. The structure types are accordant with the typical secondary metabolites from Myrsinaceae family. Benzoquinones were isolated as main components from the stems and twigs of A. corniculatum, so the benzoquinones are probably the substantial constituents of the folk medicine to treat asthmatic, diabetic and rheumatic diseases.