Three new bibenzyl derivatives from Dendrobium candidum.
Three new compounds were isolated from the stems of Dendrobium candidum: (S)-3,4,4'-trihydroxy-5,alpha-dimethoxybibenzyl (1), named dendrocandin C; (S)-3,4,4'-trihydroxy-5-methoxy-alpha-ethoxybibenzyl (2), named dendrocandin D; and 3,3',4,4'-tetrahydroxy-5-methoxybibenzyl (3), named dendrocandin E. Their structures were elucidated by 1D- and 2D-NMR spectroscopy and mass spectroscopy. The isolated compounds exhibited potent antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, with IC(50) values of 34.2, 34.5, and 15.6 microM for compounds 1, 2, and 3, respectively. Vitamin C was used as positive control with IC(50) 23.2 microM.
Li
Yan
Y
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.
Wang
Chun-Lan
CL
Wang
Ya-Jun
YJ
Guo
Shun-Xing
SX
Yang
Jun-Shan
JS
Chen
Xiao-Mei
XM
Xiao
Pei-Gen
PG
D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001205:Ascorbic Acid / Q000737:chemistry; D001632:Bibenzyls / Q000737:chemistry* / Q000302:isolation & purification; D001713:Biphenyl Compounds; D031667:Dendrobium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol; D010851:Picrates; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
D000975:Antioxidants; D001632:Bibenzyls; D001713:Biphenyl Compounds; D010851:Picrates; D012997:Solvents; C539110:dendrocandin C; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid; D000432:Methanol