Construction and application of recombinant human UDP-glucuronosyltransferases expression systems / 药学学报

In the research and development of new drugs, it is very important to investigate the in vitro metabolism of candidate drugs. Traditional models such as liver microsomes have many limitations, while the in vitro model of recombinant human drug metabolizing enzymes is considered as an important and useful approach because of its convenient access, stable activity and low cost. In this study, six major human UDP-glucuronosyltransferases (UGTs) genes (UGT1A1, 1A3, 1A4, 1A6, 1A9 and 2B7) were cloned from human liver cDNA and heterologously expressed in Saccharomyces cerevisiae and baculovirus-infected insect cell. UGT1A1, 1A3, 1A6 and 1A9 were successfully expressed in yeast and showed glucuronidation activity against a variety of different structural types of substrates, but their activities were low. All six UGTs were successfully expressed and exhibited significantly improved glucuronidation activity when Trichopolusia ni cells BTI-TN5B1-4 (High Five) were used as the host. The recombinant human UGTs expressed in insect cells can catalyze the glucuronidation of their specific substrates, and the glucuronidation products were synthesized at milligram-scale with yields of 13%-66% for the first time, of which the structures were identified via MS, 1H NMR, and 13C NMR spectroscopic analysis. Above all, the recombinant human UGTs yeast and insect cell expression systems constructed in this study can be used for in vitro metabolism evaluation in the early stage of new drugs research and development, and also provide a new tool for the synthesis of glucuronide metabolites.

[Study on chemical bibenzyls in Dendrobium gratiosissimum].

Nineteen compounds were isolated and structurally characterized from an ethanol extract of Dendrobium gratiossimum, including dendrogratiol A(1), DDB-1(2), 3,4-dihydroxyl-5,3',4'-trimethoxybibenzyl(3), amoenylin(4), chrysotoxine(5), DTB(6), 3,4,4'-trihydroxyl-5,3'-dimethoxybenzyl(7), 3-methylgiga(8), aloifol(9), gigantol tetramethyl ether(10), batatasin Ⅲ(11), moscatilin(12), moniliformine(13), gigantol(14), DMB(15), flavanthrinin(16), cannithrene-2(17), 3,4-dihydroxyl-5,4'-dimethoxystilbene(18) and 4-hydroxy-3,5,4'-trimethoxystilbene(19). 1 was a new compound, and 2-10, 16, 18 and 19 were obtained from this plant species for the first time. In vitro cytotoxic and antiviral activities of these isolates were evaluated, which displayed that 4 showed moderate cytotoxicity against human hepatoma cell line HepG2 with the IC_(50) of 10.15 µmol·L~(-1); 7 and 12 exhibited moderate inhibitory activity towards HIV virus with the IC_(50) of 9.35 and 9.15 µmol·L~(-1), respectively; and 10 displayed inhibitory activity against IAV virus with the IC_(50) of 8.90 µmol·L~(-1).

A new lactone derivative from plant endophytic fungus Periconia sp. F-31 / 中国中药杂志

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.