60820-94-2Relevant articles and documents
Efficient enzymatic preparation of esculentoside B following condition optimization by response surface methodology
Cui, Pan,Dou, Tong-Yi,Sun, Yan-Ping,Li, Shi-Yang,Feng, Lei,Zou, Li-Wei,Wang, Ping,Hao, Da-Cheng,Ge, Guang-Bo,Yang, Ling
, p. 25 - 31 (2016)
Esculentoside B (EsB, also named phytolaccagenin 3-O-β-d-xylopyranoside), a pentacyclic triterpene isolated from herbal medicine Radix phytolaccae, has been found to possess multiple pharmacological activities. Nonetheless, the low content in nature and the difficulties in the total synthesis of EsB strongly limit its extensive investigations and further development as a drug candidate. This study aims to provide a practical method for highly efficient preparation of EsB using esculentoside A (EsA, phytolaccagenin 3-O-β-d-glucopyranosyl (1 → 4)-β-d-xylopyranoside) as the starting material. β-d-glucosidase from snailase was used to catalyze the formation of EsB, and the product was then purified and fully characterized by both HRMS and NMR. To prepare EsB in a more cost-effective way, response surface methodology (RSM) was used to explore the potential effects of the reaction conditions (such as reaction temperature, pH, enzyme load, and reaction time) on the conversion rates of EsA. The highest EsB yield of 0.66 mg/ml was obtained experimentally under optimized conditions as follows: temperature 48.28 °C, pH 6.4, enzyme load 4.43%, and reaction time 2.73 h. This result agreed well with the predicted yield of 0.68 mg/ml by RSM. The enzymatic kinetics of this biotransformation was characterized at the optimum pH and temperature. The S50 value was evaluated as 167.4 μM, while the Vmax value was 345.6 nmol/min/mg. In summary, this study provided a mild and practical method for the highly efficient preparation of EsB from EsA, which held great promise for large scale production of EsB.
New approaches to the structural modification of olean-type pentacylic triterpenes via microbial oxidation and glycosylation
Zhu, Yu-Yao,Qian, Li-Wu,Zhang, Jian,Liu, Ji-Hua,Yu, Bo-Yang
experimental part, p. 4206 - 4211 (2011/07/08)
Microbial transformation of 4 olean-type pentacyclic triterpenes (OPTs), 3-oxo oleanolic acid (1), 3-acetyl oleanolic acid (2), oleanolic acid (3), and esculentoside A (4) was studied. After the screening of 12 strains of microbes, preparative biotransformation by two strains of Streptomyces griseus ATCC 13273 and Aspergillus ochraceus CICC 40330 resulted in the isolation of 10 metabolites. The microbial catalyzed high efficient regio-selective methyl oxidation and glycosylation were discovered, which could be provided as an alternative method to expand the structural diversity of OPTs. All the structures of the metabolites were elucidated unambiguously by ESI-MS, 1H NMR, 13C NMR, and 2D-NMR spectroscopy.
