Objective Asiatic acid is the main medicinal component of aursane pentacyclic triterpene and possessed various biological activities. In order to obtain better active Asiatic acid analogues, microbial transformation was used for structural modification. Methods Asiatic acid was biotransformed by Syncephalum racemosum CGMCC 3.2500. The structure of the compound was identified by high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) and nuclear magnetic resonance spectroscopy (i.e., ¹H NMR、¹³C NMR、¹H-¹³C HSQC、¹H-¹³C HMBC、¹H-¹H NOESY). Results The structure of the compound was determined as 2-oxo-3α, 15α, 23-trihydroxyurs-12-en-28-oic acid which was a new compound. Conclusion Syncephalum racemosum CGMCC 3.2500 can modify the structure of Asiatic acid and obtain Asiatic acid analogues.

Objective To study the release profile of curcumin and piperine from the compound self-microemulsion. Methods The release of curcumin and piperine in vitro was investigated by dynamic dialysis under the condition of phosphate buffer of pH 4.8 and 7.5 with 0.75% Tween-80. Results The cumulative release rates of curcumin in pH 4.8 and pH 7.5 were 94.85% and 84.38% in 108 h, respectively. The cumulative release rates of piperine were 92.85% and 90.05% in 36 h, separately. Conclusion Curcumin and piperine in self-microemulsion have sustained release properties and released more in the acidic environment similar to the environment in tumors.