Metildigoxin

Fermentation is a key process in Congou black tea, but there is limited research on the changes in flavor factors and their interrelationships during different fermentation stages under industrial production. This study applies sensory evaluation and metabolomics techniques to explore the interactions between flavors. Sensory evaluation indicated that the 4-h fermented sample exhibited the best overall performance. The experiment of adding aroma substances further revealed the significant effects of sweet aroma and green odor on taste of sweetness and astringency. Additionally, 532 flavor compounds were identified using high-resolution liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Moreover, significant differences were observed in the volatile compounds derived from flavonoids, amino acids, and fatty acids of samples with different fermentation degrees. Furthermore, weighted co-expression network analysis of flavor compounds showed that the oxidation of polyphenols, especially catechins, plays an important regulatory role in content changes of volatile and other non-volatile compounds during fermentation.

There is growing interest in exploring Digitalis cardenolides as potential antiviral agents. Hence, we herein investigated the influence of structural features and lipophilicity on the antiherpes activity of 65 natural and semisynthetic cardenolides assayed in vitro against HSV‐1. The presence of an α,β‐unsaturated lactone ring at C‐17, a β‐hydroxy group at C‐14 and C‐3β‐OR substituents were considered essential requirements for this biological activity. Glycosides were more active than their genins, especially monoglycosides containing a rhamnose residue. The activity enhanced in derivatives bearing an aldehyde group at C‐19 instead of a methyl group, whereas inserting a C‐5β‐OH improved the antiherpes effect significantly. The cardenolides lipophilicity was accessed by measuring experimentally their log P values (n‐octanol‐water partition coefficient) and disclosed a range of lipophilicity (log P 0.75±0.25) associated with the optimal antiherpes activity. In silico studies were carried out and resulted in the establishment of two predictive models potentially useful to identify and/or optimize novel antiherpes cardenolides. The effectiveness of the models was confirmed by retrospective analysis of the studied compounds. This is the first SAR study addressing the antiherpes activity of cardenolides. The developed computational models were able to predict the active cardenolides and their log P values.