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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]

The Qujia gold deposit is located in the central part of the Jiaojia gold metallogenic belt, which is an important concentrated area of altered-type gold deposits in China. The elevation of the deposit ranges from -726 m to -1 334 m. To study the evolution of pyrite and its indicative role in gold mineralization processes, in-situ trace element analysis of pyrite was conducted using LA-ICP-MS. The pyrites were categorized through petrographic observation and cluster analysis. It is revealed that trace elements such as Co, Ni, and As in pyrite mainly in the form of isomorphism, while elements such as Au, Ag, Cu, Zn, Pb, and Bi predominantly exist as mineral inclusions at the nano- and micron-scale. Pyrite is classified into five main types: Co-rich Pyl, Ni-rich Py2, Au- and As-rich Py3, Au-, Ag-, Pb-, and Bi-rich Py4, and "clean" Py5. The trace element characteristics of pyrite indicate that ore-forming materials may have primarily originated from Precambrian metamorphic basement rocks and Mesozoic magmatic rocks, with a lesser contribution from the mantle. Ore-forming hydrothermal fluids likely resulted from a complex mix of metamorphic hydrothermal fluids, magmatic hydrothermal fluids, and shallow atmospheric precipitation. The different types of pyrite reflect the evolution of ore-forming hydrothermal fluids from Co- and Ni-rich to As- and Au-rich, and finally to Pb-, Bi-, Au-, and Ag-rich compositions. After the formation of Pyl and Py2, intense tectonic activities caused significant disturbance and enhanced the adsorption of gold complex compounds onto fracture surfaces, promoting gold precipitation within the fractures. This process likely played an important role in gold enrichment and mineralization. Pyrite with low Co and Ni contents but high fragmentation levels, as well as elevated concentrations of Au, Ag, As, Pb, and Bi, is closely associated with mineralization. In addition, the content of Co and Ni in pyrite is high, the crushing is strong, and the content of ore-forming elements is high, which is the characteristics of pyrite formed in the early stage and transformed by the later mineralization. [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]

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]

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.

Two new flavonoids (1 and 2), along with 14 known ones (3-16), were isolated from the cultured cells of Glycyrrhiza 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.

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.

The Xa21 gene previously cloned from the wild rice species Oryzae longistaminata confers broad-spectrum resistance to rice leaf blight caused by different strains of Xanthomonas oryzae pv. oryzae. Here we attempted to determine the existence of Xa21 homologs in other wild rice species and rice cultivars and the sequence differences between the homologs. We synthesized specific primers based on the reported Xa21 sequence to amplify homologs of the gene exon II from several rice cultivars and three wild rice species in Yunnan Province, China. The fragments cloned from various types of O. rufipogon Griff from Jinghong and Yuanjiang, Yunnan Province, were highly homologous to the reported Xa21 gene exon II. However, the fragment was not found in O. officinalis Wall. and O. meyeriana Baill. Sequence analysis suggested that differences in nucleotides were located randomly in the fragments we cloned.