Fourteen new 2-benzylbenzofuran glycosides with cardioprotective activity from Heterosmilax yunnanensis.

Fourteen new 2-benzylbenzofuran O-glycosides (1-13, 15) and one new key precursor, diarylacetone (14) were isolated from the roots of Heterosmilax yunnanensis Gagnep, which all have characteristic 2,3,4-O-trisubstituted benzyl. Their structures were elucidated by 1D and 2D NMR, HRESIMS, UV and IR. The isolated compounds were assessed for their cardioprotective activities and compounds 1, 3 and 6 could significantly improve cardiomyocytes viability. Moreover, the mechanistic study revealed that these three compounds could significantly decrease intracellular ROS levels and maintain mitochondrial homeostasis upon hypoxia inducement. Consequently, 1, 3 and 6 might serve as potential lead compounds to prevent myocardial ischemia.

Six undescribed lavandulylated flavonoids with PTP1B inhibition from the roots of Sophora flavescens.

Six undescribed lavandulylated flavonoids (1-6) were isolated from the roots of Sophora flavescens. Remarkably, compounds 1 and 2, which were composed of a flavane unit and a phloroglucinol unit, were the first reported dimers. Compounds 3 and 4 were the first reported neoflavonoids with lavandulyl units. Compounds 5 and 6 were chalcone with oxidized lavandulyl units. Their structures were fully characterized by cumulative analyses of UV, IR, HRESIMS, NMR and ECD spectroscopic data, along with computational calculations through density functional theory. Compounds 1 and 2 showed significant protein tyrosine phosphatase-1B inhibitory activities with IC50 values of 2.669 and 3.596 µM, respectively.

An ingenious method for the determination of the relative and absolute configurations of compounds containing aryl-glycerol fragments by 1H NMR spectroscopy.

A concise method was established to determine the relative and absolute configurations of aryl-glycerols that depend on the chemical shift differences (Δδ) of the diastereotopic methylene protons (H-3) by 1H NMR spectroscopy. When using DMSO-d 6 as the preferred solvent, the threo configuration corresponded to a larger Δδ H3a-H3b value (>0.15 ppm), whereas the erythro configuration (<0.07 ppm) corresponded to a smaller value. Furthermore, the absolute configurations were determined with the aid of a simple acylation reaction through camphanoyl chloride. In the threo enantiomers, the Δδ value of the 1R,2R configuration was <0.15 ppm, and that of the 1S,2S configuration was >0.20 ppm. In the erythro enantiomers, the Δδ value of 1R,2S was >0.09 ppm, and that of 1S,2R was <0.05 ppm. Remarkably, this empirical rule is invalid in CDCl3. In addition, this method was also verified by a quantum 1H NMR calculation.