Isolation, Identification and Chemical Modification of Bufadienolides from Bufo melanostictus Schneider and Their Cytotoxic Activities against Prostate Cancer Cells.

The traditional Chinese medicine toad venom (Venenum bufonis) has been extensively used to treat various diseases, including cancers, in China and other Southeast Asian countries. The major constituents of toad venom, e.g., bufadienolides and alkaloids, exhibit broad-spectrum pharmacological effects in cancers. Herein, two new bufadienolides (1 and 2), along with eleven known compounds (3-13) were successfully isolated from Bufo melanostictus Schneider. Their structures were elucidated by extensive spectroscopic data and X-ray diffraction analysis. Furthermore, four lactam derivatives were synthesized through the transformation of bufadienolides lactones. The inhibitory effects of these compounds against human prostate cancer cell lines PC-3 and DU145 were evaluated. The outcomes indicated a notable trend, with a substantial subset displaying nanomolar range IC50 values against PC-3 and DU145 cells, underscoring their pronounced cytotoxicity. Moreover, a noteworthy distinction surfaces, wherein lactones consistently outperformed their lactam counterparts, further validating their heightened potency for the treatment of prostate cancer. This study contributes significant preclinical evidence substantiating the therapeutic viability of bufadienolides and toad venom as intervention strategies for prostate cancer.

Cassaine diterpenoid glycosides from the seeds of Erythrophleum fordii Oliv. and their antiviral and anti-inflammatory activities.

Seven new cassaine diterpenoids (1-7) along with four known ones (8-11) were isolated from the seeds of Erythrophleum fordii Oliv. (Leguminosae). Their chemical structures were elucidated by extensive spectroscopic data interpretation and chemical methods. Compound 1 is a rare unsymmetrical dimer, which is formed by the linking of another cassaine diterpenoid acid glycoside to the 6-hydroxyl group of the sugar unit in a cassaine amide glycoside through an ester bond. Compound 2 is a cassaine diterpenoid acid derivative featuring an unusual Z double bond at C-13 and C-15. The in vitro antiviral and anti-inflammatory activities of 1-11 were evaluated. The results showed that compounds 1, 2 and 3 showed significant antiviral activities against human respiratory syncytial virus (RSV) with IC50s of 6.3, 7.8, and 9.4 µM, respectively. Compound 9 significantly suppressed the expression of nuclear factor-kappa B (NF-κB) with an IC50 value of 2.6 µM.

Cassaine diterpenoids from the seeds of Erythrophleum fordii and their cytotoxic activities.

Six new cassaine diterpenoids (1, 3-7), along with three known ones (2, 8-9) were isolated from the seeds of Erythrophleum fordii. Their structures were elucidated by extensive spectroscopic methods and acid hydrolysis. Compound 2 was tested to be the most potent one and showed more sensitive activities on MCF-7 and A549 cancer cells with IC50 values of 3.66 ±â€¯1.20 and 2.87 ±â€¯0.46 µM, respectively. Furthermore, compound 2 reduced the number of cell colonies significantly in a dose-dependent manner in the colony formation assay and triggered apoptosis of MCF-7 cell.