tailieunhanh - Antifungal constituents from the stems of dracaena cambodiana

The stems of Dracaena cambodiana have been investigated for antifungal constituents, resulting in the isolation of a new steroidal saponin dracagenin A (1) together with two known components 25S-namogenin B (2) and spriroconazole A (3). Their structures were elucidated on the basis of extensive spectroscopic analysis including 1D, 2D NMR and ESI MS. The isolated compounds were evaluated for their antifungal activities. 1 and 3 exhibited inhibitory activity against Aspergilus niger at the MICs of 50 μg/ml. | Journal of Chemistry, Vol. 46 (4), P. 503 - 508, 2008 ANTIFUNGAL CONSTITUENTS FROM THE STEMS OF DRACAENA CAMBODIANA Received 6 September 2007, Revised 1 November 2007 Nguyen Hai Dang1, Phan Van Kiem1, Chau Van Minh1, and Tran Thu Huong2 Institute of Natural Products Chemistry, Vietnamese Academy of Science and Technology 1 Faculty of Chemical Technology, Hanoi University of Technology, summary summary The stems of Dracaena cambodiana have been investigated for antifungal constituents, resulting in the isolation of a new steroidal saponin dracagenin A (1) together with two known components 25S-namogenin B (2) and spriroconazole A (3). Their structures were elucidated on the basis of extensive spectroscopic analysis including 1D, 2D NMR and ESI MS. The isolated compounds were evaluated for their antifungal activities. 1 and 3 exhibited inhibitory activity against Aspergilus niger at the MICs of 50 μg/ml. No inhibition effects on F. oxysporum, S. cerevisiae and C. albicans have been found for the tested compounds. Interestingly, toxicity of 3 towards several cancer cell lines has been demonstrated. The IC50 of 3 against Hep-2, Lu, and RD are , , and μg/ml, respectively. Keywords: Dracaenaceae, Dracaena cambodiana, Steroidal saponin, Dracagenin A. I - INTRODUCTION Dracaena cambodiana (Dracaenaceae) is mostly distributed in the North of Vietnam. The plant has been found in ethnomedicine to treat menoschesis, ostealgia etc (Bich, 2006; Chi, 1997; Loi, 2001). Investigations on the chemical constituents of the genus revealed that the spirosterol and steroidal saponin are among the major components (Gonzalez, 2004; Mimaki, 1998). Interestingly, there has been no report on the phytochemical of D. cambodiana. On our continuing studies for antifungal agents, we have isolated a new steroidal saponin namely dracagenin A (1), one sprirosterol 25Snamogenin B (2) and one known steroidal saponin spriroconazole A (3). The antifungal activities of these compounds .