Biol. Pharm. Bull., 28(1),158-160, January 2005

Notes

Antitubercular Activity of Triterpenoids from Asteraceae Flowers

Toshihiro AKIHISA,^*,a Scott G. FRANZBLAU,^b Motohiko UKIYA,^a Hiroki OKUDA,^a Fangqiu ZHANG,^b Ken YASUKAWA,^c Takashi SUZUKI,^c and Yumiko KIMURA^c

^a College of Science and Technology, Nihon University; 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan: ^b Institute for Tuberculosis Research, College of Pharmacy (M/C 964), University of Illinois at Chicago; 833 S. Wood St., Chicago, IL 60612, U.S.A.: and ^c College of Pharmacy, Nihon University; 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan. * To whom correspondence should be addressed. e-mail: akihisa@chem.cst.nihon-u.ac.jp

Twenty-eight 3-hydroxy triterpenoids of taraxastane- (1-7), oleanane- (8-12), ursane- (13-15), lupane- (16,18,19), taraxane- (20), cycloartane- (21-25), tirucallane- (26-28), and dammarane-types (29) isolated from the non-saponifiable lipid fraction of the flower extract of chrysanthemum (Chrysanthemum morifolium) and one lupane-type 3α-hydroxy triterpenoid (17) derived from 16 were tested for their antitubercular activity against Mycobacterium tuberculosis strain H₃₇Rv using the Microplate Alamar Blue Assay (MABA). Fifteen compounds showed a minimum inhibitory concentration (MIC) in the range of 4-64 μg/ml, among which maniladiol (9; MIC 4 μg/ml), 3-epilupeol (17; 4 μg/ml), and 4,5α-epoxyhelianol (27; 6 μg/ml) exhibited the highest activity. Cytotoxicity of compound 17 against Vero cells gave an IC₅₀ value of over 62.5 μg/ml, suggesting some degree of selectivity for M. tuberculosis.

Key words triterpenoid; Chrysanthemum morifolium; chrysanthemum flower; Mycobacterium tuberculosis; antituberculosis; antimycobacterial