Cytotoxic and antimicrobial labdane and clerodane diterpenoids from Kaempferia elegans and Kaempferia pulchra

Publication date: April 2018 Source:Phytochemistry Letters, Volume 24 Author(s): Pornsuda Chawengrum, Jutatip Boonsombat, Prasat Kittakoop, Chulabhorn Mahidol, Somsak Ruchirawat, Sanit Thongnest Three previously undescribed diterpenoids, propadanes A-C (1-3), together with seventeen known compounds (4-20), were isolated from the rhizomes of Kaempferia elegans and Kaempferia pulchra. The structures of the isolated compounds were elucidated through extensive analysis of spectroscopic data. The absolute configuration (12R) of propadane A (1) was established by CD analysis. (−)-Kolavelool (15) and (−)-2β-hydroxykolavelool (18) showed selective cytotoxic activity against the HL-60 cell line with IC50 values of 8.97 ± 0.66 and 9.58 ± 0.88 μg/mL, respectively. Anticopalic acid (5), anticopalol (10), and 8(17)-labden-15-ol (11) showed antimicrobial activity against the Gram positive bacterium, Bacillus cereus, with MIC values of 3.13, 6.25, and 6.25 μg/mL, respectively. Labdane-type diterpenoids were found to be common constituents in K. elegans, while clerodane-type diterpenoids were common in K. pulchra. This information could be used to establish their chemotaxonomy. Graphical abstract

Source: Phytochemistry Letters - March 21, 2018 Category: Chemistry Source Type: research