Spin-charge interconversion of two-dimensional electron gases at oxide interfaces.

Oxide two-dimensional electron gas (2DEG) is a low-dimensional carrier system formed at the interface of oxide heterojunctions with strong and tunable Rashba spin-orbit coupling which makes oxide 2DEG an ideal platform for converting spin current and charge current. This review provides a summary of the recent advances on the 2DEGs at oxide interfaces for spin-charge interconversion. On one hand, we analyze properties and the efficiency of the spin-to-charge conversion through different ways of spin current injection. On the other hand, the conversion of charge current to spin current under different experimental methods has been summarized. These research achievements provide perspectives and methods for understanding and regulating the spin-charge interconversion of the 2DEG at the oxide interface.

Two new polyketides from endophytic fungus Pestalotiopsis sp. HQD-6 isolated from the Chinese mangrove plant Rhizophora mucronata.

Mangrove endophytic fungi were proved to be a prolific resources for bioactive secondary metabolites. Two new polyketides, pestalotiopin B (1) and pestalotiopyrone N (2) were obtained from the ethyl acetate extracts of the rice solid cultures of the mangrove endophytic fungus Pestalotiopsis sp. HQD-6. The structures of 1 and 2 were determined by detailed interpretation of NMR spectroscopic analysis and HR-ESIMS. All of the isolates were evaluated for their antimicrobial, antioxidant and cytotoxic activities.

Cytotoxic constituents from the mangrove endophytic Pestalotiopsis sp. induce G0/G1 cell cycle arrest and apoptosis in human cancer cells.

Chemical examination of Chinese mangrove Rhizophora mucronata endophytic Pestalotiopsis sp., yielded  11 known metabolites with various structure types, including demethylincisterol A3 (1), dankasterone B (2), (22E, 24R)-ergosta-7,9(11), 22-triene-3ß, 5α, 6α-triol (3), ergosta-5,7,22-trien-3-ol (4), 5, 8-epidioxy-5, 8-ergosta-6, 22E-dien-3-ol (5), stigmastan-3-one (6), stigmast-4-en-3-one (7), stigmast-4-en-6 -ol-3-one (8), flufuran (9), (2-cis, 4-trans)-abscisic acid (10), similanpyrone B (11). Their structures were unambiguously elucidated on the basis of extensive NMR spectroscopic and mass spectrometric analyses. Compounds 1, 4, 6-9 showed significant in vitro cytotoxicity against the human cancer cell lines Hela, A549 and HepG, of which compound 1 was the most potential with IC50 values reaching nM degree ranging from 0.17 to 14.16 nM. Flow cytometric investigation demonstrated that compound 1 mainly inhibited cell cycle at G0/G1 phase in a dose-dependent manner with a significant induction of apoptosis on the three tested cell lines. The involvement of the mitochondria in compound 1 induced apoptosis was investigated using MMP. We suggested that R. mucronata endophytic Pestalotiopsis sp. contained a potential anticancer compound demethylincisterol A3.