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Six new prenylated flavonoid glycosides, including four new furan-flavonoid glycosides wushepimedoside A–D (1 – 4) and two new prenyl flavonoid derivatives wushepimedoside E–F (5 – 6), and one know analog epimedkoreside B (7) were isolated from biotransformation products of the aerial parts of Epimedium wushanense. Their structures were elucidated according to comprehensive analysis of HR-MS and NMR spectroscopic data, and the absolute configurations were assigned using experimental and calculated electronic circular dichroism (ECD) data. The regulatory activity of compounds 1 – 7 on the production of testosterone in primary rat Leydig cells were investigated, and 4 and 5 exhibited testosterone production-promoting activities. Molecular docking analysis suggested that bioactive compounds 4 and 5 showed the stable binding with 3 β -HSD and 4 also had good affinity with Cyp17A1, which suggested that these compounds may regulate testosterone production through stimulating the expression of the above two key proteins. [ABSTRACT FROM AUTHOR]

Compound 1, a triterpenoid saponin from Ardisia gigantifolia Stapf showing potential anti-tumour activity, was hydrolysed into two deglycosyl derivatives (2 and 3) by Alternaria alternata AS 3.6872. Both these derivatives are new compounds. Their structures were elucidated on the basis of 1D, 2D NMR, HR-ESI-MS and optical rotation spectral data. Compounds 1–3 were evaluated for their cytotoxicity against human hepatocellular carcinoma and normal liver cells by Cell Counting Kit 8 colorimetric assay. [ABSTRACT FROM AUTHOR]

Compound 1, a triterpenoid saponin from Ardisia gigantifolia Stapf. showing potential anti-tumor activity, was transformed into three derivatives (2–4) by Aspergillus avenaceus 3.4454. Among them, compounds 2 and 3 are new compounds. Their structures were elucidated on the basis of 1D NMR, 2D NMR, HR-ESI-MS, and optical rotation data. Compounds 1–3 were evaluated for their cytotoxicity against human hepatocellular carcinoma and normal liver cells by cell counting kit 8 colorimetric assay. Compound 3 displayed better cytotoxicity against Bel-7402 and HepG2 cell lines and much weaker cytotoxicity against normal liver L02 cell than that of positive control (epirubicin hydrochloride). [ABSTRACT FROM AUTHOR]

Abstract: Twelve flavonoid glycosides were involved in the biotransformation of the glycosyl moieties by Curvularia lunata 3.4381, and the products were analyzed by UPLC/PDA-Q-TOF-MSE. Curvularia lunata displayed hydrolyzing activities on the terminal Rha or Glc units of some flavonoid glycosides. Terminal Rha with a 1→2 linkage of isorhamnetin-3-O-neohesperidoside and typhaneoside could be hydrolyzed by Curvularia lunata, but terminal Rha with a 1→6 linkage of rutin, typhaneoside, and quercetin-3-O-apiosyl-(1→2)-[rhamnosyl-(1→6)]-glucoside could not be hydrolyzed. Curvularia lunata could also hydrolyze the Glc of icariin, floramanoside B, and naringin. This is the first report of the hydrolysis of glycosyl units of flavonoid glycosides by Curvularia lunata. A new way to convert naringin to naringenin was found in this research. [Copyright &y& Elsevier]

Five commercial enzyme preparations were screened for hydrolysis of the glucuronic acid units of glycyrrhizin (GL) and baicalin. Two preparations hydrolyzing GL to glycyrrhetic acid (GA) and four enzyme preparations hydrolyzing baicalin to baicalein were obtained. One enzyme preparation with the ability to hydrolyze both GL and baicalin, namely Rapidase Pineapple, was purified by anion exchange, cation exchange and molecular sieve chromatography. The results of purification indicated that the enzymes containing the glycyrrhizin-β- d-glucuronidase (GBDG) and baicalin-β- d-glucuronidase (BBDG) activities were distinct, with different substrate specificities, molecular weights and enzymatic characteristics. GBDB hydrolyzed GL to GA, but had no detectable activity on baicalin, and BBDG hydrolyzed baicalin to baicalein, but could not hydrolyze GL. However, both GBDG and BBDG could hydrolyze the artificial substrate p-nitrophenyl- β- d-glucuronide (pNPGA). [ABSTRACT FROM AUTHOR]

Timosaponin BII (1), a steroidal saponin showing potential anti-dementia activity, was regioselectively hydrolyzed into its deglycosyl derivatives by the crude enzyme from Aspergillus niger AS 3.0739. Three biotransformation products, timosaponin BII-a (2), timosaponin BII-b (3), and timosaponin BII-c (4), were purified and their structures were elucidated on the basis of 1D NMR, 2D NMR, FAB-MS, and HR-ESI-MS spectral data. Compounds 2 and 3 are new compounds. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To study the hydroxylation in glycyrrhetinic acid (GA) by biocatalysis, and evaluate the antibacterial activities of the derivatives. Methods: The hydroxylation was performed via incubating GA with a fungus, Cunninghamella blakesleeana (C. blakesleeana) AS 3.970 at 30 °C for 5 days. Results: GA was converted into two major derivatives and four minor derivatives. The two major derivatives were isolated and elucidated as 3-oxo-7β-hydroxy-glycyrrhetinic acid (GA-1) and 7β-hydroxy-glycyrrhetinic acid (GA-2) based on their spectral data, and other derivatives (GA-3–GA-6) were identified by HR-ESI-MS. The antibacterial activities of substrate and two major derivatives were evaluated on four bacteria strains and one yeast strain. Conclusion: Cunninghamella blakesleeana AS 3.970 has the capability of hydroxylation for GA. The two major derivatives and GA were found to have considerable activities against drug-resistant Enterococcus faecalis. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To study of structural modification in steroidal saponin by biotransformation technology. Methods: Structural modification was carried out of glycosyl residues of dichotomin at C-3 position by Pectinex BE XXL (PBX). Cytotoxicity against HL-60 cells of all products was investigated. Results: The PBX could hydrolyze the glycosyl residues of dichotomin one-by-one to produce nine transformed compounds. The transformed product (mixture) and four secondary spirostanosides among them exhibited cytotoxicity. Compounds P5, P6 and P7 with α-1, 2 end-rhamnosyl residues showed a potential cytotoxic effect on HL-60 cells; P8 with α-1, 4 end-rhamnosyl residue had a weak effect on HL-60 cells. Dichotomin, secondary furostanosides and aglycone were not cytotoxic. Conclusion: PBX has various hydrolyzation to the glycosidic bonds of dichotomin. Nine obtained transformed compounds widen steroidal saponin library. Meanwhile, screening activity affords data for further pharmacological study. [Copyright &y& Elsevier]

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 (1H-1H COSY, HSQC, HMBC and NOESY) and MS spectrometry, their structures were established as 7β, 15α-dihydroxy-3,11-dioxo-oleana-12-en-30-oic acid (1) and 15α-hydroxy-3,11-dione-oleana-12-en-30-oic acid (2), respectively. [ABSTRACT FROM AUTHOR]

Abstract: The microbiological transformation of polyphyllin I (compound I ), polyphyllin III (compound II ), polyphyllin V (compound III ) and polyphyllin VI (compound IV ) by Curvularia lunata into their corresponding subsaponins, for example, diosgenin-3-O-α-l-arabinofuranosyl (1→4)-β-d-glucopyranoside (compound V ), diosgenin-3-O-α-l-rhamnopyranosyl (1→4)-β-d-glucopyranoside (compound VI ), diosgenin-3-O-β-d-glucopyranoside (compound VII ) and pennogenin-3-O-β-d-glucopyranoside (compound VIII ), were studied in this paper. Curvularia lunata is able to hydrolyze terminal rhamnosyls that are linked by 1→2 C– bond to sugar residues of steroidal saponins at C-3 position with high activity and regioselectivity. [Copyright &y& Elsevier]

Five new steroidal saponins ( 1 – 5 ) were isolated from the fermentation broth of total furostanol glycosides from tubers of Dioscorea zingiberensis C.H. Wright incubated with a fungal, Absidia coerulea AS 3.3389, along with known saponins, zingiberensis new saponin ( 6 ), deltonin ( 7 ), prosapogenin A of dioscin ( 8 ), and protobioside ( 9 ), and their structures were established by NMR spectroscopy and mass spectrometry as well as by comparison with previously reported spectral data in the literatures. The induced effects in vitro on rat platelet aggregation of all compounds were evaluated. [ABSTRACT FROM AUTHOR]

In this study seven strains of the genus Arthrobacter were screened by biotransformation to discover glycosylating patterns on steroid saponins. A strain of Arthrobacter nitroguajacolicus (CPCC 203516) was found to have the ability of fructosylation. Crude enzyme of the strain was extracted for the further study of conversion characteristics and patterns. Sucrose was used as a non-activated sugar donor, and fifteen steroidal saponins were involved. Nine furostan saponins of the substrates were converted, and ten products were isolated and identified. Based on the HR-ESI-MS, 1D, and 2D NMR spectral data, one fructosyl was added to furostan saponins at C 6 -OH of 26- O -β- d -glucopyranosyl by A. nitroguajacolicus for all nine products. One product was distinguished by an additional fructosyl at the position of C 6 -OH on the first added fructosyl. Spirostan saponins of the substrates could not be converted. Steroidal saponins embracing a fructosyl are quite rare according to other reports based on similar studies. This study successfully converted furostan saponins into new compounds. [ABSTRACT FROM AUTHOR]

Abstract: It is known that the sugar chain linked to steroidal frame plays an important role in physiological and pharmacological activities. In the previous research, we found and confirmed that the terminal C3-O-α-1,2-rhamnosyl moiety linked to the C-3 of steroidal saponin is the key group of platelet aggregation and cytotoxicity. In order to make a complete approach for the structure–activity relationship, we have tried to find the specific enzymes modifying the structure of C3-sugar chain. In the present paper, we describe a novel enzyme from, Klerzyme-150 (K-150), which is specifically capable of hydrolyzing the α-1,4-glycosyl residues at C-3 postion of steroidal saponins. 15 steroidal saponins with different monosaccharides at C3-sugar chains were chosen as substrates to investigate the substrate specificity of K-150. The results showed, based on TLC, HPLC and spectra data analyses, that all products were determined as secondary saponins with the α-1, 4-glycosyl residues removed, which indicated that the enzyme exhibited strict regioselectivity and stereoselectivity. The novel enzyme was purified from K-150 to apparent homogeneity and its structure was identified as rhamnogalacturonan lyase A (Rgl A). The molecular mass of the purified enzyme was 52.08kDa. [Copyright &y& Elsevier]