Cardenolides and pentacyclic triterpenes isolated from leaves: their biological activities with molecular docking study.

Pentacyclic triterpenes and cardenolides were isolated from leaves. Their chemical structures were determined based on comprehensive 1D and 2D NMR spectroscopy. Their MIC was determined against 12 microorganisms. Their exerted cytotoxicity on the immortalized normal cells, hTERT-RPE1 was assessed by the sulforhodamine-B assay. The viral inhibitory effects of compounds against Newcastle disease virus (NDV) and H5N1 influenza virus IV were evaluated. Four antioxidant assays were performed in comparison with BHT and trolox and a weak activity was exhibited. Acovenoside A was with potent against H5N1-IV and NDV with IC ≤ 3.2 and ≤ 2.1 μg/ml and SI values of 93.75 and 95.23%, respectively, in comparison to ribavirin. Its CC record on Vero cells was > 400 and 200 μg/ml, respectively. Acobioside A was the most active compound against a broad range of microbes while was the most sensitive. Its MIC (0.07 μg/ml) was 1/100-fold of the recorded CC (7.1 μg/ml/72 h) against hTERT-RPE1. The molecular docking of compounds on human DNA topoisomerase I (Top1-DNA) and IV glycoprotein hemagglutinin were studied using MOE program. This study has introduced the cardenolides rather than triterpenoids with the best docking score and binding interaction with the active site of the studied proteins.