Molecular structure characteristic of coals of different rank.

Context: Understanding the structural characteristics of coal at the molecular level is fundamental for its effective utilization. To explore the molecular structure characteristic, the long-flame coal from Daliuta (DLT), coking coal from Yaoqiao (YQ), and anthracite from Taixi (TX) were investigated using various techniques such as elemental analysis, Fourier transform infrared spectroscopy, solid-state C nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy. Based on the structural parameters, the coal molecular model was constructed and optimized.

Research hotspots and trends of comprehensive utilization of phosphogypsum: Bibliometric analysis.

Phosphogypsum is a by-product of the phosphate fertilizer industry. It is generally treated by stacking, which not only causes environmental pollution, but also wastes resources. Therefore, the harmless, comprehensive, and high-value utilization of phosphogypsum has attracted more and more scholars around the world.

Revision of the structure of isochaetoglobosin D based on NMR analysis and biosynthetic consideration.

Isochaetoglobosin D is a new chaetoglobosin possessing a unique 3,4-substituted pyrrole ring isolated and named by Qiu , and it is different from any one of the 14 sub-types in the macrocyclic ring of chaetoglobosins classified in our previous work. Its chemical shift values, coupling constants and biosynthetic consideration implied that the proposed structure of isochaetoglobosin D was incorrect. In this report, based on detailed NMR data analysis together with biosynthetic consideration, the structure of isochaetoglobosin D is suggested to be revised to that of penochalasin C.

[Chemical constituents from endophyte Chaetomium globosum in Imperata cylindrical].

Isolation and purification of chemical constituents from solid culture of endophyte Chaetomium globosum in Imperata cylindrical was performed through silica gel column chromatography, gel filtration over Sephadex LH-20 and preparative HPLC. Nine compounds were obtained and their structures were determined as chaetoglobosin F(1), chaetoglobosin Fex(2), chaetoglobosin E(3) cytoglobosin A(4), penochalasin C(S), isochaetoglobosin D (6), N-benzoylphenylalaninyl-N-benzoyphenylalaninate(7), uracil(8) and 5-methyluracil(9), respectively, based on HR-MS and NMR data and comparison with literatures. Compound 7 was isolated from Chaeeomium sp.

A new cytochalasin from endophytic Phomopsis sp. IFB-E060.

Aim: To study the chemical constituents of the solid culture of the endophyte Phomopsis sp. IFB-E060 in Vatica mangachapoi.

Method: Isolation and purification were performed through silica gel column chromatography, gel filtration over Sephadex LH-20, ODS column chromatography, and HPLC.