Search

Short-chain dehydrogenase/reductases (SDRs) belong to the NAD(P)(H)-dependent oxidoreductase superfamily, which have various functions of catalyzing oxidation/reduction reactions and have been generally used as powerful biocatalysts in the production of pharmaceuticals. In this study, ScSDR1 and ScSDR2, two new SDRs have been identified and characterized from Stachybotrys chartarum 3.5365. Substrate scope investigation revealed that both of the enzymes possessed the ability to oxidize β-OH to ketone specifically, and exhibited substrate promiscuity and high stereo-selectivity for efficiently catalyzing the structurally different prochiral ketones to chiral alcohols. These findings not only suggest that ScSDR1 and ScSDR2 might be potent synthetic tools in drug research and development, but also provide good examples for further engineered enzymes with higher efficiency and stereo-selectivity. [ABSTRACT FROM AUTHOR]

Anhydroicaritin (1a), baohuoside (1b) and icariin (1c) were recognized as major pharmacologically active ingredients of Epimedium plants. Their primary means of acquisition were chemical isolation from plants. However, it suffers from low yield, environmental pollution and shortage of plants. Herein, to remedy these problems, biosynthesis was explored to obtain the three active ingredients. Fortunately, with SfFPT as 8-prenyltransferase, EpPF3RT and Ep7GT as glycosyltransferases, kaempferide (1) was transferred to 1a, 1b and 1c enzymatically. Thus, we report the details of this method. This approach represents a promising environmental friendly alternative for the production of these compounds from an abundant analogue. [ABSTRACT FROM AUTHOR]

Peridecalins C and D (1 and 2), one decalin and one oxygen-decalin containing polyketide-amino acid hybrids with 5/6/6 ring system, was isolated from a genetic mutant of Periconia sp. F-31. Their structures were elucidated through extensive spectroscopic data analysis, including 1 D/2D NMR and HR-MS spectra. Biosynthetically, two proposed Diels-Alder reactions are supposed to be involved in the skeleton construction of 1 and 2. [ABSTRACT FROM AUTHOR]

AbstractEpimedium is widely used in traditional Chinese medicine and contains rich bioactive compounds. These compounds often have a methyl group at their 4’-OH position catalyzed by methyltransferases. Therefore, studying methyltransferases in Epimedium plants is of great significance. In this study, a flavonol methyltransferase, EpOMT4, was isolated from Epimedium pseudowushanense B.L. Guo. The recombinant enzyme regiospecifically transferred a methyl group to the 4’-OH position of 8-prenylkaempferol forming icaritin. The study demonstrates that enzymatic methylation of flavonoids in Epimedium plants holds significant potential and could provide a promising alternative method for the biosynthetic production of bioactive methylated prenylflavonoids. [ABSTRACT FROM AUTHOR]

Bistachybotrysin K (1), one new phenylspirodrimane dimer with a central 6/7 oxygen heterocycle core, was isolated from the fungus Stachybotrys chartarum CGMCC 3.5365. Its structure was elucidated by extensive spectroscopic data and single-crystal X-ray diffraction. Compound 1 showed significant cytotoxicity against human tumor cell lines HCT116, NCI-H460, BGC823, Daoy, and HepG2 with IC50 values in the range of 1.1–4.7 µM. [ABSTRACT FROM AUTHOR]

Various bioactive polyketides have been found in Aloe barbadensis. However, the polyketide synthases (PKSs), which participate in biosynthesis of polyketides in A. barbadensis remain unknown. In this study, two type III PKSs (AbPKS1 and AbPKS2) were identified from A. barbadensis. AbPKS1 and AbPKS2 were able to utilize malonyl-CoA to yield heptaketides (TW93a and aloesone) and octaketides (SEK4 and SEK4b), respectively. AbPKS1 also exhibited catalytic promiscuity in recognizing CoA thioesters of aromatics to produce unusual polyketides. What Is more, a whole cell biocatalysis system with the capability of producing 26.4 mg/L of SEK4/SEK4b and 2.1 mg/L of aloesone was successfully established. [ABSTRACT FROM AUTHOR]

Two new lanostane triterpenoids (1 and 2), two new ergostane-type steroids (3 and 4) together with two known lanostane triterpenoids (5 and 6) and one known steroid (7) were isolated from the cultured mycelia of Ganoderma capense (CGMCC 5.71). Their structures were determined on the basis of extensive spectroscopic (HRESIMS, 1D NMR, 2D NMR) data analyses. Compound 1 exhibited moderate cytotoxic activity against the human cancer cell line NCI-H1650 with an IC50 value of 22.3 μM, and 7 displayed cytotoxic activity against the human cancer cell line HCT116 with an IC50 value of 17.4 μM. In addition, compounds 2, 3, 5, and 6 displayed weak anti-HIV activity with IC50 values of 23.5, 46.7, 21.6, and 30.1 μM, respectively. [ABSTRACT FROM AUTHOR]

Three new sesquiterpenoids trichoacorenols B–C and cyclonerodiol B (1–3), along with three known ones (4–6), were isolated from the mangrove plant endophytic fungusTrichodermasp. Xy24 using various column chromatography techniques. The structures of these compounds were determined on the basis of extensive spectroscopic data analyses. Compounds1,2,4, and5were four acorane sesquiterpenes,3and6were two monocyclic sesquiterpenediols. Compounds3and5exhibited significant neural anti-inflammatory activity by inhibiting LPS-induced NO production in BV2 cells with the inhibitory rates of 75.0% and 39.2% at 0.1 μM, respectively, which are more potent than curcumin, a positive control with the inhibitory rate of 21.1% at 0.1 μM. [ABSTRACT FROM PUBLISHER]

Two new flavonoids (1and2), along with 14 known ones (3–16), were isolated from the cultured cells ofGlycyrrhiza uralensis. Most of them were prenylated flavonoids. Their structures were elucidated on the basis of spectroscopic data analysis. All compounds showed non-cytotoxicity against five human tumor cell lines. The results suggest that plant cultured cells can yield the secondary metabolites that have not been found in parent plant. [ABSTRACT FROM AUTHOR]

Biotransformations of icariin (1) by cell suspension cultures ofGlycyrrhiza uralensisandMorus albayielded two new metabolites, icaruralins A and B (2and3), and one known metabolite, baohuoside I (4). Their structures were determined on the basis of extensive spectroscopic analysis. This is the first report that the cell suspension cultures ofG. uralensisandM. albapossess deglycosylation functionality. [ABSTRACT FROM AUTHOR]

One new eremophilane sesquiterpene periconianone L ( 1 ), together with four known guaiane-type sesquiterpenes 4,10,11-trihydroxyguaiane ( 2 ), (-)-guai-1(10)-ene-4 α ,11-diolhydroxymecuration ( 3 ), guaidiol A ( 4 ), and epi-guaidiol A ( 5 ) were isolated from the endophytic fungus Periconia sp. F-31. The structure of the new compound was established by spectroscopic methods, including UV, IR, HRESIMS, and extensive NMR techniques. Compound 3 was isolated as natural product for the first time.

The glycosides of 4'-demethylepipodophyllotoxin (DMEP) possess various pharmacological activities; however, the chemical synthesis of these glycosides faces challenges in regioselectivity, stereoselectivity, and the protection and de-protection of functional groups. In this work, a novel glycosyltransferase (GT) gene AbGT5 from Aloe barbadensis was successfully cloned, heterogeneously expressed and purified. Recombinant AbGT5 was able to catalyze the glycosylation of DMEP and the glycosylated product, which was separated from the preparative scale reaction, was characterized as DMEP 4'-O-β-D-glucoside via MS, 1H-NMR, 13C-NMR, HSQC and HMBC. According to the investigations of enzyme properties, AbGT5 show the highest activity around 20 ℃ in the buffer of pH 9.0, and it was independent of divalent metal ions. Under the optimum conditions, the conversion rate of DMEP can reach 80%. Above all, in this work the enzymatic glycosylation of DMEP was achieved with high efficiency by the novel GT AbGT5., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Secoisolariciresinol dehydrogenase (SDH) is a key enzyme involved in the biosynthetic pathway of podophyllotoxin.In this study, two SDH candidate genes,SO282 and SO1223, were cloned from callus of Dysosma versipellis by homology-based PCR and rapid amplification of cDNA end (RACE).The SDH candidate genes were expressed in Escherichia coli and the subsequent enzyme assay in vitro showed that recombinant SO282 had the SDH activity. These results pave the way to the follow-up investigation of the biosynthetic of podophyllotoxin., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Various chromatographic techniques, including silica gel column chromatography, Sephadex LH-20, preparative thin-layer chromatography, and preparative HPLC, were employed to isolate the chemical constituents from callus cultures of Dysosma versipellis. Structures of the compounds were elucidated based on UV, IR, MS and NMR spectroscopic data analysis. Totally, seven flavonoid glycosides were isolated from the 95% ethanol extract of the callus cultures and identified as kaempferol-3-O-[6″-(3″'-methoxy)-malonyl]-β-D-glucopyranoside(1), kaempferol-3-O-(6″-O-acetyl)-β-D-glucopyranoside(2), kaempferide-3-O-β-D-glucopyranoside(3), kaempferol-3-O-β-D-glucopyranoside(4), isoquercitrin(5), quercetin-4'-O-β-D-glucopyranoside(6) and kaempferol-3-(6″-malonyl)-β-D-glucopyranoside(7), respectively.All these compounds were isolated from callus cultures of D. versipellis for the first time.Compounds 1, 2, 3, 6 and 7 were firstly obtained from plant materials of D. versipellis, and compound 1 was a new compound., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

To investigate the secondary metabolites of endophytic fungi Pericinia sp. F-31. Column chromatography on silica gel, Sephadex LH-20 and semi-preparative HPLC were used to separate and purify the compounds. Two compounds were isolated from the fermentation broth of Periconia sp. Their structures were identified as 5-(1-hydroxyhexyl) -6-methyl-2H-pyran-2-one (1) and 2-(3-hydroxy-4-methylphenyl) -propanoic acid (2). Compound 1 was a new lactone compound, compound 2 was new natural product, and the NMR data of compound 2 was reported for the first time.

Naringenin (1) was transformed to three metabolites (2-4) by Mucor sp. Based on LCMS(n)-IT-TOF and NMR spectroscopic data, 2-4 were identified as naringenin-7-O-sulphate, naringenin-4'-O-sulphate, and naringenin-5-O-sulphate, respectively. These results might provide hints to the mammalian/human metabolism of naringenin.