Lasiokaurin derivatives: synthesis, antimicrobial and antitumor biological evaluation, and apoptosis-inducing effects

Herein, a series of lasiokaurin derivatives were designed and synthesized. All the derivatives together with lasiokaurin and oridonin were tested for their antimicrobial and antiproliferative activity. Compound 16 showed the most promising antimicrobial activity with MICs of 2.0 and 1.0 μg/mL against Gram-Positive bacteria S. aureus and B. subtilis, respectively. All the synthetic lasiokaurin derivatives showed better antiproliferative activity than parent compound lasiokaurin 1. Compound 10 exhibited the strongest cytotoxicity with IC₅₀ values of 0.47 and 0.20 μM against MGC-803 and CaEs-17 cells, accordingly. Moreover, it was shown to have potent antitumor activity in vivo in a murine model of MGC-803 gastric cancer. Preliminary SARs were also concluded based on obtained data. The apoptosis-inducing effects of 10 were further investigated using CaEs-17 cells. The results showed that lasiokaurin derivative 10 could induce apoptosis via mitochondria related pathway and arrest CaEs-17 cell cycle at S phase. Compound 10 could also affect apoptosis-related proteins that was up-regulation of CDK2 and down-regulation of ATM and cyclin A1.