The fruits of (Chinese black cardamom; Zingiberaceae) contain an abundance of essential oils, which have previously demonstrated significant antimicrobial activity. In our preliminary search for natural anti-tuberculosis agents, an acetone extract of . – (AAE) exhibited strong antibacterial activity against H37Rv. Therefore, the aim of this study was to find the principal compounds in an AAE against . . Nine aliphatic compounds (-) including a new compound (, tsaokol B) and a new natural unsaturated aliphatic diester (), together with three acyclic terpenoids (-), were isolated from an AAE by repetitive chromatography. The structures of the isolates were determined by spectroscopic data analysis. All isolates were evaluated for activity against . H37Rv. Isolated compounds -, and had MICs ranging from 0.6-89 µg/mL. In contrast, compounds to , and had MICs that were >100 µg/mL. Tsaokol A () was the most active compound with MICs of 0.6 µg/mL and 1.4 µg/mL, respectively, against replicating and nonreplicating . . These results are the first to illustrate the potency of tsaokol A () as a natural drug candidate with good selectivity for treating tuberculosis.
