Antimicrobial phenolic metabolites from the aerial parts of Orthosiphon aristatus

• Published in: Phytochemistry letters 2022-12, Vol.52, p.49-53
• Main Authors: Tung, Nguyen Ngoc, Tam, Le Thi, Anh, Do Hoang, Hanh, Tran Thi Hong, Cuong, Nguyen Xuan, Cuong, Nguyen The, Quang, Tran Hong
• Format: Article
• Language: English
• Subjects: Antimicrobial; Lamiaceae; Orthosiphon aristatus; Phenolics
• ISSN: 1874-3900; 1876-7486
• DOI: 10.1016/j.phytol.2022.09.004

Two new compounds oraristatin A (1) and oraristatinoside A (2), one new natural compound (2 S)-methyl-6,7-dihydroxytropate (3), and 11 known phenolic metabolites were isolated from the aerial parts of Orthosiphon aristatus. Their chemical structures were identified by 1D- and 2D NMR and HRESIMS spectroscopic analyses. The absolute configurations of 1 and 3 were determined by TD-DFT ECD spectroscopic analyses. Of the isolates, compound 2 weakly inhibited both Gram-positive and -negative bacteria (MIC = 150–300 μM), while 6 and 7 suppressed the growth of three Gram-positive bacteria and a yeast (MIC = 75–150 μM). This is the first report of the isolation of 6 − 9, 12, and 14 from the genus Orthosiphon and the antimicrobial effects of compounds 3, 7, 9, 12, and 14. [Display omitted] •14 compounds were isolated from Orthosiphon aristatus.•Two new, one new natural, and 11 known compounds were structurally elucidated.•Antimicrobial effects of extract, fractions, and compounds were evaluated.