Synthesis of Pyridin-2(1H)-imines via the Transformation of Conjugated Ynones.

Conjugated ynones represent an important class of reactive species, useful synthetic intermediates, and synthons. However, the reactivity and synthetic applications of ynones are usually focused on the transformation of mono- or dual-functional groups. Herein, we developed a straightforward synthesis of pyridin-2(1H)-imines from the transformation of conjugated ynones. This cascade process probably began with a Michael addition of ynones and 2-aminopyridines, further underwent an intramolecular cyclization to generate the N,O-bidentate intermediates, and finally reacted with sulfonyl azides giving the pyridin-2(1H)-imines with accompanying loss of diazo.

Bibliometric and visualized analysis of type 2 diabetic osteoporosis from 2013 to 2022.

Type 2 diabetic osteoporosis (T2DOP) has received increasing attention from researchers. In this study, a total of 453 publications related to T2DOP from 2013 to 2022 were analyzed using bibliometric and visual analysis to identify the research trends and research hotspots in the field of T2DOP. PURPOSE: The objective of this study was to conduct a comprehensive bibliometric analysis of T2DOP-related publications from 2013 to 2022 to determine global research trends in T2DOP in terms of number of publications, countries/regions, institutions, authors, journals, funding agencies, and keywords. METHODS: All data were collected from the Web of Science Core Collection (WoSCC). All original research publications regarding T2DOP from 2013 to 2022 were retrieved. VOSviewer and Microsoft Office Excel were used to conduct the bibliometric and visual analysis. RESULTS: From 2013 to 2022, 515 relevant publications were published, with a peak in 2022 in the annual number of publications. The countries leading the research were USA and China. Sugimoto was the most influential authors. Capital Medical University and Nanjing Medical University were the most prolific institutions. Osteoporosis International was the most productive journal concerning T2DOP research. National Natural Science Foundation of China was the primary funding source for this research area. "Bone-mineral density", "fracture risk", and "postmenopausal women" were the most high-frequency keywords over the past 10 years. CONCLUSION: This was the first bibliometric study of diabetes mellitus and osteoporosis to exclusively examine type 2 diabetes mellitus. Our findings would provide guidance to understand the research frontiers and hot directions in the near future.

Undescribed matrine-type alkaloids from Sophora alopecuroides with anti-inflammatory activity.

A phytochemical investigation on the alkaloid fractions of Sophora alopecuroides L. led to the production of 11 undescribed matrine-type alkaloids, sophaloseedlines I-S (1-11), 12 known analogs (12-23), and an unexpected artificial matrine-derived Al(III) complex (24). The corresponding structures were elucidated by the interpretation of spectroscopic analyses, quantum chemical calculation, and six instances (1-4, 18, and 24), verified by X-ray crystallography. The biological activities screening demonstrated that none of the isolates exhibited cytotoxicity against four human cancer cell lines (HepG2, A549, THP-1, and MCF-7) and respiratory syncytial virus (RSV) at 50 µM, while moderate anti-inflammatory activity with IC50 value from 15.6 to 47.8 µM was observed. The key structure-activity relationships of those matrine-type alkaloids for anti-inflammatory effects have been summarized. In addition, the most potent 7-epi-sophoramine (19) and aluminum sophaloseedline T (24) could effectively inhibit the release of pro-inflammatory factors (TNF-α, IL-6, and IL-1ß), as well as the expression of iNOS and COX-2 proteins.

Discovery and Biomimetic Synthesis of a Polycyclic Polymethylated Phloroglucinol Collection from Rhodomyrtus tomentosa.

Inspired by a previously reported biomimetic synthesis study, four new naturally occurring phloroglucinol trimers 1-4 with unusual 6/5/5/6/6/6-fused hexacyclic ring systems, along with two known analogues (5 and 6) and two known biogenetically related dimers (10 and 11), were isolated from Rhodomyrtus tomentosa. Their structures and absolute configurations were unambiguously elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculation. By mimicking two potentially alternative biosynthetic pathways, the first asymmetric syntheses of 1-4 and the racemic syntheses of 5 and 6 were achieved in only five to six steps without the need for protecting groups. Furthermore, phloroglucinol dimers 10 and 11 exhibited significant in vitro antiviral activity against the respiratory syncytial virus.

Rhodomentosones A and B: Two Pairs of Enantiomeric Phloroglucinol Trimers from Rhodomyrtus tomentosa and Their Asymmetric Biomimetic Synthesis.

Rhodomentosones A and B (1 and 2), two pairs of novel enantiomeric phloroglucinol trimers featuring a unique 6/5/5/6/5/5/6-fused ring system were isolated from Rhodomyrtus tomentosa. Their structures with absolute configurations were elucidated by NMR spectroscopy, X-ray crystallography, and ECD calculation. The bioinspired syntheses of 1 and 2 were achieved in six steps featuring an organocatalytic asymmetric dehydroxylation/Michael addition/Kornblum-DeLaMare rearrangement/ketalization cascade reaction. Compounds 1 and 2 exhibited promising antiviral activities against respiratory syncytial virus (RSV).