New indolequinazoline alkaloids from the fruits of Tetradium ruticarpum.

In this research, five new indolequinazoline alkaloids (1-5), along with six known indolequinazoline alkaloids (6-11) were obtained from the fruits of Tetradium ruticarpum. Their structures were elucidated through comprehensive spectroscopic data of 1D and 2D NMR, HRESIMS and ECD spectra. Additionally, all isolates were assayed for their SIRT1 inhibitory activities in vitro and compounds 2, 7, 10 and 11 exhibited activities with IC50 values ranged from 43.16 to 118.35 µM.

Withanolides from Physalis angulata var. villosa and the Relative Configurational Revision of Some Known Analogs.

Physalis angulata var. villosa is a plant possessing abundant withanolides, but in-depth research is lacking. In our ongoing study of P. angulata var. villosa, 15 previously undescribed withanolides (1-15), along with 21 known analogs (16-36), were isolated from the whole plant. The structures of the withanolides (1-15) were elucidated based on analysis of their 1D and 2D NMR, HRESIMS, and ECD data. Additionally, the application of γ-gauche effects with the help of ROESY correlations led to the formulation of empirical rules for withanolides with 14-OH/15-OAc to rapidly determine the 14-OH orientations, making it possible to propose configurational revisions of 19 previously reported analogs (1'-19'). Withanolides 1, 4-6, and 10 showed potent cytotoxic activities against three human cancer cell lines (HCT-116, MDA-MB-231, and A549).

Withanolides from Physalin angulata and Their Inhibitory Effects on Nitric Oxide Production.

Six new withanolides, angulasteroidins A-F (1-6), along with twelve known analogs (7-18) were isolated from the whole plants of Physalis angulata. Their structures were elucidated by analysis of 1D and 2D NMR, ECD and IR spectra, HR-ESI-MS data, and ECD calculation. Compounds 1 and 6 were rare 1-10 seco withanolides. Compounds 2-4, 7-9, and 15 exhibited significant inhibitory activity on the production of nitric oxide in the LPS-activated RAW 264.7 mouse macrophage cell lines with IC50 values ranging from 0.23 to 9.06 µM.

New N-oxide alkaloids from the stems of Sinomenium acutum.

Six new alkaloids (1-6) and six known alkaloids (7-12) were obtained from the stems of Sinomenium acutum. Among them, compounds 1-3 and 6 were four N-oxide alkaloids. The structures and absolute configurations of these new alkaloids were elucidated through comprehensive data of 1D and 2D NMR, HRESIMS and ECD spectra. All isolated compounds were evaluated in vitro for their inhibitory activities against nitric oxide (NO) production and inhibitory effects on AChE. Among them, the sinomenine N-oxide (9) was the most potent NO production inhibitor, with an IC50 value of 23.04 µM.