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The special electronic configuration of phosphorus atoms endows organophosphorus reagents with unique chemical properties, which enable them to be used to catalyze various organic reactions, such as the Wittig reaction, Staudinger reaction, Appel reaction and Mitsunobu reaction. However, the catalytic process will be accompanied by the generation of large amounts of phosphine oxide waste, resulting in the reduction of atom utilization of the reaction, and it is difficult to separate the product. Therefore, it is essential to explore a greener and more sustainable organic synthesis route based on the catalytic cycle of phosphine oxide as a model. This paper summarizes the catalytic cycle and recycling of phosphorus with or without reducing agents and reviews the related developments in recent decades: from the addition of stoichiometric strong reducing agents, to the design of ring phosphines with specific structures, to the development of new energy inputs (electrochemistry), to the addition of a series of compounds to activate the P(V)O double bond, driving the catalytic cycle of phosphine oxide through chemical transformation. This review also points out the development potential of this field in the future, which will promote its development and progress in a greener direction.

The coupling reaction allows simple structural fragments to be constructed and sequentially assembled by C-X bond to synthesize a variety of active molecular frameworks. Different from the traditional single-metal catalyst, the synergistic effect of bimetal provides special catalytic activity that cannot be obtained by traditional single-metal catalyst, thus emerging as an efficient alternative mode. In this paper, we used CuAl bimetallic heterogeneous mesoporous materials to participate in the sequential assembly of CS and CN bonds, which effectively catalyzed the synthesis of 2-substituted benzothiazole heterocyclic systems. In addition, GW610 with antitumor activity was synthesized easily and efficiently by this strategy.

Trametenolic acid B (TAB) was a lanostane-type triterpenoid isolated from the trametes lactinea (Berk.) Pat. We have previously reported that extract from trametes lactinea (Berk.) Pat and TAB could efficiently improve learning and memory ability of the cerebral ischemia injury rats and suppress mitochondrial-mediated apoptosis in hydrogen peroxide damaged SH-SY5Y cells. However, the potential mechanisms have not been fully understood yet. The current study was to further investigate the protective effect of TAB on oxygen glucose deprivation/reoxygenation (OGD/R)-damaged SH-SY5Y cells and cerebral ischemia/reperfusion (I/R) injury rats, as well as its mechanisms involved. Cell experiments demonstrated that TAB (10, 20 and 40 μg/mL) protected OGD/R-induced SH-SY5Y cell injury by promoting cell proliferation and suppressing LDH leakage; Meanwhile, the results in vivo showed that TAB (20, 40 and 80 mg/kg) might significantly ameliorate the neurological deficit score, cerebral edema, neuronal cell loss and apoptosis, suppress cerebral infarction volume of the cerebral I/R injury rats. Further studies in vitro and in vivo indicated TAB could efficiently reduce OGD/R-damaged SH-SY5Y cell and cerebral I/R rat serum ROS, LDH and MDA levels, elevate SOD, GSH-Px and CAT activities, downregulate miR-10a mRNA and Bax, cytochrome C, cleaved-caspase-3 and cleaved-caspase-9 protein expressions, upregulate p-PIK3CA, p-Akt, p-mTOR, Bcl-2, pro-caspase-9 and pro-caspase-3 protein expressions and p-PIK3CA/PIK3CA, p-Akt/Akt, p-mTOR/mTOR ratios (P

Seeking a strategy for triggering the cryptic natural product biosynthesis to yield novel compounds in the plant-associated fungus Xylaria sp., the effect of culture conditions on metabolite production was investigated. A shift in the production of five known cytochalasin-type analogues 1–5 to six new α-pyrone derivatives, xylapyrones A–F (compounds 6–11), from a solid to a liquid medium was observed. These compounds were identified by analysis of 1D and 2D NMR and HRMS data. Compounds 1–3 showed moderate cytotoxicity against HepG2 and Caski cancer cell lines with IC50 values ranging from 25 to 63 μM and compounds 4–11 were found to be inactive, with IC50 values >100 μM.

In the title compound, C15H24O4, the six-membered ring shows a distorted chair conformation and the five-membered ring adopts an envelope conformation with the C atom bearing the methyl and OH groups as the flap. In the crystal, O—H...O hydrogen bonds link the molecules into chains running along the a-axis direction.

Two new thiazole and thiadiazole alkaloids, penicilliumthiamine A and B (2 and 3), were isolated from the culture broth of Penicillium oxalicum, a fungus found in Acrida cinerea. Their structures were elucidated mainly by spectroscopic analysis, total synthesis and X-ray crystallographic analysis. Biological evaluations indicated that compound 1, 3a and 3 exhibit potent cytotoxicity against different cancer cell lines through inhibiting the phosphorylation of AKT/PKB (Ser 473), one of important cancer drugs target.

S-Glycosides are considerably more stable toward chemical degradation and enzymatic hydrolysis than O-glycosides, and thioglyco-peptides/proteins also demonstrate critical bioactivities in the living system. However, the general and stereoselective synthetic strategies are still challenging. Herein, a versatile S-glycosylation approach was developed by palladium-catalyzed allylic substitution to form a- and ß-thioglycosides respectively under mild conditions. A wide range of substrates were tolerated to afford thioglycosides in a stereospecific manner with 70%-86% yields. This protocol also created the quick access to various S-linked disaccharides and glycopeptides. [ABSTRACT FROM AUTHOR]