Glycosides are the active ingredients (AIs) of many Chinese herbs and have become hot spots along with the findings of their new functions,such as anti-inflammatory,antivirus,enhanced immunity and anti-cancer.It has been found that glycosides exert their effects by converting to aglycons or other AIs in vivo.Therefore,the transformation of glycosides to the corresponding AIs in vitro becomes very important to enhance their bioavailabilities.The microbial transformation has an unparalleled advantage in the transformation of Chinese herbs in vitro for its reaction specificity,less by-products,mild reaction conditions and environmental protection.This paper summarized and prospected researches of glycosides' microbial transformation.

Objective:To observe the effects of acupoint application on TRPV1 expression on skin and lung tissue and levels of serum IFN-γ and IL-4 of mice with bronchial asthma, and to explore the mechanism of acupoint application in the treatment of asthma.Methods:75 BALB/C mice were divided into control group, model group, acupoint application group, sham application group and dexamethasone group, 15 in each group. The bronchial asthma model of mice was prepared by nasal drop method of Dermatophagoides pteronyssinuus (HDM). After the modeling, the acupoints such as "Feishu", "Xinshu" and "Geshu" of each side of the mice were taken for application. The acupoint application group was treated with white mustard seed, Corydalis yanhusuo, asarum and Gansui group, while the sham application group was treated with vaseline, once a day, 14 times in total. Emka-wbp pulmonary function detection system was used to detect airway resistance in mice. The expression of TRPV1 on lung tissues and skin tissues were detected by immunohistochemical method. The levels of IFN-γ and IL-4 were detected by ELASA method.Results:After the stimulation of methacholine chloride solution at the concentrations of 12.5, 25.0 and 50.0 mg/ml, compared with the model group, the Penh value (airway high resistance) of mice in the acupoint application group and dexamethasone group decreased ( P<0.05). HE staining and Sirius red staining of lung tissue showed that inflammatory infiltration and collagen fiber proliferation had been improved ( P<0.05). Compared with model group, the expression of TRPV1 (0.28±0.06, 0.28±0.05 vs. 0.31±0.08) in lung tissues of acupoint application group and dexamethasone group significantly decreased ( P<0.05). The levels of IFN-γ and IL-4 in BALF decreased ( P<0.05). Conclusion:The mechanism of skin reaction induced by acupoint application in treating asthma may be related to the changes of IFN-γ, IL-4 and other related factors caused by the activation of TRPV1 in lung tissues and skin tissues.

Covalently anchoring of a ligand/metal via polar amino acid side chain(s) is often observed in metalloenzyme, while the substitutability of metal-binding sites remains elusive. In this study, we utilized a zinc-dependent alcohol dehydrogenase from Thermoanaerobacter brockii (TbSADH) as a model enzyme, analyzed the sequence conservation of the three residues Cys37, His59, and Asp150 that bind the zinc ion, and constructed the mutant library. After experimental validation, three out of 224 clones, which showed comparative conversion and ee values as the wild-type enzyme in the asymmetric reduction of the model substrate tetrahydrofuran-3-one, were screened out. The results reveal that the metal-binding sites in TbSADH are substitutable without tradeoff in activity and stereoselectivity, which lay a foundation for designing ADH-catalyzed new reactions via metal ion replacement.
Alcohol Dehydrogenase/metabolism* ; Catalytic Domain ; Ligands ; Protein Domains ; Zinc/metabolism*