Novel biologically active bibenzyls from Bauhinia saccocalyx Pierre.
Four new bibenzyls, bauhinols A-D (1-4), together with the two known bibenzyls 5 and 6, were isolated from the roots of Bauhinia saccocalyx, and their structures were elucidated by analyses of spectroscopic data. Bauhinol A (1) exhibits significant cytotoxicity towards NCI-H187 (small-cell lung cancer), BC (breast cancer), and KB (oral-cavity cancer) cell lines, with IC50 values of 2.7-4.5 microg/ml. Bauhinol B (2) is cytotoxic against NCI-H187 (IC50 = 1.1 microg/ml) and BC (IC50 = 9.7 microg/ml) cell lines, but inactive toward the KB cell line (at 20 microg/ml). Compound 2 also is mildly antifungal towards Candia albicans (IC50 = 28.9 microg/ml). Bibenzyl 6 is active against NCI-H187 (IC50 = 14.1 microg/ml) and BC (IC50 = 4.0 microg/ml) cells, but inactive (at 20 microg/ml) toward the KB cell line. Compounds 1, 2, and 6 show mild antimycobacterial activities, with MIC values of 25-50 microg/ml, but are inactive at 20 microg/ml against the K1 malarial parasite strain (Plasmodium falciparum). While bauhinol A (1) is inactive against cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2), compounds 2 and 6 inhibit both COX-1 and COX-2, with IC50 values comparable to those of the standard drug, aspirin (Table 3).
Apisantiyakom
Samneang
S
School of Chemistry, Institute of Science, Suranaree University of Technology, 111 University Ave., Muang District, Nakhon Ratchasima 30000, Thailand.
Kittakoop
Prasat
P
Manyum
Thanaporn
T
Kirtikara
Kanyawim
K
Bremner
John B
JB
Thebtaranonth
Yodhathai
Y
D000818:Animals; D036481:Bauhinia; D001632:Bibenzyls / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001685:Biological Factors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D002478:Cells, Cultured; D006801:Humans; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots; D010963:Plasmodium falciparum / Q000187:drug effects
D001632:Bibenzyls; D001685:Biological Factors; D010936:Plant Extracts