Abstract:
Phytochemical investigation of a methanol extracts prepared from Dendrobium pachyglossum and Dendrobium heterocarpum, Orchidaceae, led to the the isolation of thirteen compounds. One new bizbibenzyl compound and 6 known compounds including 4,5-dihydroxy-2,3-dimethoxy-9,10-phenanthrene, moscatilin, gigantol, 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl, dendrocandin T, and isovitexin were separated from D. pachyglossum. From D. heterocarpum, 6 compounds were isolated including amoenylin, methyl 3-(4-hydoxyphenyl) propionate, 3,4-dihydroxy-5,4'-dimethoxybibenzyl, dendrocandin B, dendrofalconerol A, and syringaresinol, respectively. The structure of isolated compounds were determined by analysis of spectroscopic data (NMR and HR-ESI-MS). They were then investigated for cytotoxicity and cytoprotective effect against hydrogen peroxide-induced oxidative stress on HaCaT keratinocytes. The result showed that dendropachol, isovitexin, methyl 3-(4-hydoxyphenyl) propionate, and syringaresinol at concentration of 50 µg/mL showed non-toxicity as compared the untreated group. In addtion, It was found that pre-treatment with dendropachol, methyl 3-(4 hydoxyphenyl) propionate, and syringaresinol protected HaCaT keratinocyte cells by preventing hydrogen peroxide-induced oxidative stress as compared with untreated group.
