Quality Evaluation System of Standard Decoction of Puerariae Thomsonii Radix / 中国实验方剂学杂志

Objective: To establish the quality control methods for the standard decoction of Puerariae Thomsonii Radix.Method:According to the preparation principles for traditional Chinese medicine (TCM) standard decoction,13 batches of Puerariae Thomsonii Radix from different origins were analyzed under the chromatography conditions established in this study and verified with methodology.By referring to Chinese Pharmacopoeia of 2015,puerarin was used as a quantitative indicator to calculate the transfer rate.In this study,the structures of main chromatographic peaks were also identified to clarify the main chemical constituents in the standard decoction.Result:The 13 batches of medicinal herbs were identified as Puerariae Thomsonii Radix,with a recovery rate of 98.0%,and RSD of 1.1%,indicating that the method was accurate and reliable.The transfer rate ranged from 41.4% to 60.0%,and the extraction rate was within the range of 15.7%-34.3%.The corresponding fingerprints were prepared for 13 batches of the standard decoction,and their similarities were all greater than 90.0%.The chemical constituents from Puerariae Thomsonii Radix were identified by mass spectrometry analysis,including citric acid,4'-O-glucosyl puerarin/daidzein-4',7-diglucoside,3'-hydroxy puerarin/genistein puerarin,puerarin apioside,daidzin puerossid A and daidzein,etc.Conclusion: The 13 batches of Puerariae Thomsonii Radix decoction in different origins had consistent properties with the basic properties of medicinal decoction pieces.The established method of quality evaluation can be used to systematically evaluate the standard decoction,providing reference for quality control of related decoction preparations of Puerariae Thomsonii Radix.

Study of heterologous efficient synthesis of cucurbitadienol / 中国中药杂志

Cucurbitadienol has anti-inflammation, anti-cancer activities, and acts as a precursor of traditional Chinese medicine active ingredients mogroside and cucurbitacine. For construction of a Sacchromyces cerevisiae cell factory for production of cucurbitadienol, we firstly cloned a cucurbitadienol synthase (CBS) gene from Siraitia grosvenorii. Then, through heterologous expression of CBS in the triterpenoid chassis strain WD-2091, the engineered strain could produced 27.44 mg•L ⁻¹ cucurbitadienol, which was determined by GC-MS. Further regulation of CBS expression led to cucurbitadienol's titer increasing by 202.07% and reaching 82.89 mg•L ⁻¹ in the shake flask fermentation and 1 724.10 mg•L ⁻¹ in the high cell density fermentation. Our research promotes the cucurbitane-type tetracyclic triterpenoids synthesis pathway analysis progress and provides the basis for further obtaining cell factories for production of cucurbitadienol tetracyclic triterpenoids.