Structure elucidation and complete NMR spectral assignments of glucosylated saponins of cantalasaponin I.

Five new glucosylated steroidal glycosides, cantalasaponin I-B(1) (1), I-B(2) (2), I-B(3) (3), I-B(4) (4) and I-B(5) (5), were isolated and purified from the transformed product of the cantalasaponin I by using Toruzyme 3.0 l as biocatalyst. Their structures were elucidated on the basis of high-resolution electrospray ionization mass spectrometry, one-dimensional ((1) H and (13) C NMR) and two-dimensional [COSY, heteronuclear single-quantum correlation (HSQC), HMBC and HSQC-TOCSY] NMR spectral analyses and chemical evidence.

Enzymatic synthesis of alpha-glucosyl-timosaponin BII catalyzed by the extremely thermophilic enzyme: Toruzyme 3.0L.

Timosaponin BII (BII), a steroidal saponin showing potential anti-dementia activity, was converted into its glucosylation derivatives by Toruzyme 3.0L. Nine products with different degrees of glucosylation were purified and their structures were elucidated on the basis of (13)C NMR, HR-ESI-MS, and FAB-MS spectra data. The active enzyme in Toruzyme 3.0L was purified to electrophoretic homogeneity by tracking BII-glycosylase activity and was identified as Cyclodextrin-glycosyltransferase (CGTase, EC 2.4.1.19) by ESI-Q-TOF MS/MS. In this work, we found that the active enzyme catalyzed the synthesis of alpha-(1-->4)-linked glucosyl-BII when dextrin instead of an expensive activated sugar was used as the donor and showed a high thermal tolerance with the most favorable enzymatic activity at 100 degrees C. In addition, we also found that the alpha-amylases and CGTase, that is, GH13 family enzymes, all exhibited similar activities, which were able to catalyze glucosylation in steroidal saponins. But other kinds of amylases, such as gamma-amylase (GH15 family), had no such activity under the same reaction conditions.

Glucosylation of steroidal saponins by cyclodextrin glucanotransferase.

It is known that the sugar chains of steroidal saponins play an important role in the biological and pharmacological activities. In order to synthesize steroidal saponins with novel sugar chains in one step for further studies on pharmacological activity, we here describe the glucosylation of steroidal saponins, and 5 compounds, timosaponin AIII (1), saponin Ta (2), saponin Tb (3), trillin (4) and cantalasaponin I (5), were converted into their glucosylated products by Toruzyme 3.0 L, a cyclodextrin glucanotransferase (CGTase). 12 glucosylated products were isolated and their structures elucidated on the basis of spectral data; they were all characterized as new compounds. The results showed that Toruzyme 3.0 L had the specific ability to add the α-D-glucopyranosyl group to the glucosyl group linked at the sugar chains of steroidal saponins, and the glucosyl group was the only acceptor. This is the first report of steroidal saponins with different degrees of glucosylation. The substrates and their glucosylated derivatives were evaluated for their cytotoxicity against HL-60 human promyelocytic leukemia cell by MTT assay. The substrates all exhibited high cytotoxicity (IC(50) < 10 µmol/L), excluding compound 5 (IC(50) > 150 µmol/L), and the cytotoxicity of most of the products showed no obvious changes compared with those of their substrates.

One new triterpenoid from biotransformation product of glycyrrhizic acid.

A new triterpenoid compound (1) and a known compound (2) were isolated from the product of biotransformation of glycyrrhizic acid by Aspergillus niger. On the basis of the 1D and 2D NMR ((1)H-(1)H COSY, HSQC, HMBC and NOESY) and MS spectrometry, their structures were established as 7beta, 15alpha-dihydroxy-3,11-dioxo-oleana-12-en-30-oic acid (1) and 15alpha-hydroxy-3,11-dione-oleana-12-en-30-oic acid (2), respectively.

[The clinical study on decompensatory cirrhotic patients treated by Bie Jia Jian].

OBJECTIVE: To observe the clinical curative effect on decompensatory cirrhotic patients treated by Bie Jia Jian. METHODS: 98 decompensatory cirrhotic patients were randomly divided into two groups: 49 patients in treatment group and 49 in control group. Both groups were treated with the same western medicine of protecting and supporting liver. Except that, treatment group were treated by Bie Jia Jian. RESULTS: The Contents of AST, ALT, total bilirubin (TB), direct bilirubin (DB), hyaluronic acid (HA), Laminin (LN) , procollagen III (pc III), and type IV collagen (IV.C) in both groups decreased after treatment, and prothrombin time activity (PTA) increased. Among them, the decrease of TB, DB, HA, LN, PC-III and IV-C, and the increase of PTA in treatment group were more obvious than those in control group (P < 0. 05). CONCLUSION: Bie Jia Jian is effective in treating decompesatory cirrhotic patients.

Purification, characterization, and substrate specificity of a glucoamylase with steroidal saponin-rhamnosidase activity from Curvularia lunata.

It has been previously reported that a glucoamylase from Curvularia lunata is able to hydrolyze the terminal 1,2-linked rhamnosyl residues of sugar chains at C-3 position of steroidal saponins. In this work, the enzyme was isolated and identified after isolation and purification by column chromatography including gel filtration and ion-exchange chromatography. Analysis of protein fragments by MALDI-TOF/TOF proteomics Analyzer indicated the enzyme to be 1,4-alpha-D-glucan glucohydrolase EC 3.2.1.3, GA and had considerable homology with the glucoamylase from Aspergillus oryzae. We first found that the glucoamylase was produced from C. lunata and was able to hydrolyze the terminal rhamnosyl of steroidal saponins. The enzyme had the general character of glucoamylase, which hydrolyze starch. It had a molecular mass of 66 kDa and was optimally active at 50 degrees C, pH 4, and specific activity of 12.34 U mg of total protein(-1) under the conditions, using diosgenin-3-O-alpha-L-rhamnopyranosyl(1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-glucopyranoside (compound II) as the substrate. Furthermore, four kinds of commercial glucoamylases from Aspergillus niger were investigated in this work, and they had the similar activity in hydrolyzing terminal rhamnosyl residues of steroidal saponin.

[The clinical study on chronic hepatitis B treated by the four-step therapeutics of Traditional Chinese Medicine].

OBJECTIVE: To observe the clinical curative effect of chronic hepatitis B treated by the four-step therapeutics of Traditional Chinese Medicine (TCM). METHODS: 120 patients with mild or moderate Chronic Hepatitis B (CHB) were randomly divided into two groups: 80 patients in treatment group and 40 in control group. All enrolled cases accorded with the enroll standard. In treatment group, the patients were divided into mild moderate and severe degree of immune intervention based on the ALT level and treated with four-step therapeutics according to the dialectical theory. In control group, all patients were administered 100mg Lamivudine orally daily for two years. RESULTS: The loss rates of HBeAg, HBV-DNA, precore mutation were 58.9%, 78.9% in treatment group respectively, and 33.3%, 38.9% in control group. There were significant defferences between them. The total effectiveness ratio of two groups has no significant difference. After the treatment, the value of HA, PCIII, IV. C,LN decreased dramatically in treatment group and the antihepatic fibrosis results of treatment group were superior to those of control group. The four-step therapeutics of TCM could improve the ALT value and the ALT value declined to normal after the virus indexes' loss. The response rate in treatment group of ALT-elevating patients was higher than those of no ALT- elevating patients. CONCLUSION: The four-step therapeutics of TCM is effective in treating the CHB patients.

Traditional Chinese medicine syndromes of chronic hepatitis B with precore mutant.

AIM: This study aims at exploring the distribution of TCM syndromes in CHB patients with HBV pre-core mutation (1896) and the relationship between pre-core mutation and T lymphocytes subgroup, through which to provide objective data on clinical syndrome differentiation of TCM, and further to suggest the therapeutic principle and guide clinical treatment. METHODS: One hundred and forty CHB patients were evenly divided into two study groups, HBV pre-core mutant group and HBV pre-core wild-type group. Besides, 30 healthy blood donors were selected as a healthy control group. HBV-labeled compound, T lymphocytes subgroup, and HBV-DNA pre-core mutant were tested in the study groups. T lymphocytes subgroup were also tested in the control group. All the patients were both diagnosed by syndrome differentiation of TCM and western medicine. RESULTS: The most common syndrome in mutant group was damp-heat combined with blood stasis, and the most common syndrome in the wild-type group was damp-heat stasis in the middle-jiao. There were more cases of medium and severe hepatitis in mutant group than that in wild-type group. The content of CD4+ lymphocytes and CD4+/CD8+ ratio were decreased gradually (healthy control group>wild-type group>mutant group). In the wild-type group, severe and medium CHB patients had considerably lower level of them than mild CHB patients. However, in the mutant group, the opposite result appeared. Meanwhile, the content of HBV-DNA in mutant group was higher than that in wild-type group. CONCLUSION: Damp, heat, toxin and blood stasis were the basic pathogens of CHB, whether pre-core mutant or not. CHB with precore mutant may lead to more severe hepatitis. The decreased content of CD4+ lymphocytes and ratio of CD4+/CD8+ may be taken as one of the indices in confirming the deficiency syndrome of CHB patients with pre-core mutation.