Direct, four-step synthetic pathway to iheyamine A and several analogues.

A novel synthetic route toward the pentacyclic azepinobisindole alkaloid iheyamine A and its several analogues has been developed in four steps from commercially available isatins and tryptamines. This crucial transformation involves the Bischler-Napieralski cyclization to deliver the characteristic seven-membered framework. Then the ester intermediate undergoes a hydrolyzation-decarboxylation-dehydrogenation cascade to yield the final product.

Label-free quantitative proteomics analysis of Humulus scandens (Lour.) Merr. leaves treated by an odor compound of Periploca sepium Bunge.

The odor compound from Periploca sepium Bunge, 2-hydroxy-4-methoxy-benzaldehyde (HMB), is an allelochemical agent and is one of the least investigated isomers of vanillin. In this study, we used label-free quantitative proteomics analysis technology to investigate the effect of HMB on the protein expression of Humulus scandens (Lour.) Merr. leaves in July 2019 on Guiyang. A total of 269 proteins of 624 identified proteins were differentially expressed, among which 21.18% of the proteins were up-regulated and 32.71% down-regulated. These proteins were classified into 11 cell components and more than 20% of differentially expressed proteins were located in cell membrane and chloroplast. Functional classification analysis showed that 12 molecular functions were altered upon HMB treatment, and the ratio of catalytic activity was the highest (19.53%). At least 12 biological functions were affected, which involved small molecule metabolic processes, organic substance metabolic processes, gene expression, and photosynthesis. Our data provide resources and insights into the biochemical mechanism by which HMB kills weeds.