To investigate the effects and mechanisms of 4-(1H-indol-1-yl)-4-oxobutanoic acid spliced podophyllotoxin derivatives (3a–3l) on tumor cells. The MTT method was adopted to evaluate (3a–3l) antitumor activity in vitro against A549 cells, A549/DDP cells, MCF-7 cells. The results showed that compound 3l had the most prominent inhibitory effect and high selectivity with IC50 18.53 ± 1.51 µM against A549/DDP cells. Meanwhile, the effects of compound 3l on the nuclear state, cell cycle and apoptosis of A549/DDP cells showed that compound 3l induced apoptosis by delaying the G2/M phase of A549/DDP cell cycle. In addition, molecular docking of compound 3l also showed that it could form a good hydrogen bond with ARG-158 (d = 2.6, 2.7 Å) and HIS-406 (d = 2.5 Å) at the colchicine site of tubulin. Compound 3l could provide lead compound for the development of new multi-drug resistant anti-tumor drugs.
Fubin Luo,Shuguang Yang,Zhehang Shi,Yingbing Zou,Hongzhou Li
Epoxy-based vitrimers appear as a promising alternative to common epoxy materials. Nevertheless, the possibility of epoxy vitrimers in practical applications is limited by their high flammability. In this study, a novel bio-based casein phosphopeptide chelating zinc (CPP-Zn) is purposely developed, specifically designed to serve as a flame retardant and smoke suppressant for epoxy vitrimer, operating through a condensed phase mechanism. To further enhance the fire safety of epoxy resins, DOPO derivative (DDP) is synthesized through grafting with bio-based itaconate and subsequently used as a synergistic flame retardant in combination with CPP-Zn. DDP exhibits gas phase flame retardant mechanism through the release of free radical scavangers generated during combustion. As a result of the combination of condensed and gas phase effect, the composite achieves self-extinguishing within 1 second, attains a V-0 rating in UL-94 testing, and boasts an LOI of 32.3 %. Additional, it shows a remarkable 73.7 % reduction in heat release rate (HRR) and 27.2 % in total smoke production (TSP) compared with neat epoxy vitrimer. The experimental results also evidence that the characteristic features of vitrimers, self-healing and recyclability, have been retained in the prepared flame-retarded composites. The remolded 50D/EST-25Cz is still able to maintain 72.2 % of its tensile strength . This opens promising avenues for the development of highly fire-safe and eco-friendly epoxy resins.