Utilizing a pharmacophore hybridization approach, we have designed and synthesized a novel series of 28 new heterobivalent β-carbolines. The in vitro cytotoxic potential of each compound was evaluated against the five cancer cell lines (LLC, BGC-823, CT-26, Bel-7402, and MCF-7) of different origin—murine and human, with the aim of determining the potency and selectivity of the compounds. Compound 8z showed antitumor activities with half-maximal inhibitory concentration (IC₅₀) values of 9.9 ± 0.9, 8.6 ± 1.4, 6.2 ± 2.5, 9.9 ± 0.5, and 5.7 ± 1.2 µM against the tested five cancer cell lines. Moreover, the effect of compound 8z on the angiogenesis process was investigated using a chicken chorioallantoic membrane (CAM) in vivo model. At a concentration of 5 μM, compound 8z showed a positive effect on angiogenesis. The results of this study contribute to the further elucidation of the biological regulatory role of heterobivalent β-carbolines and provide helpful information on the development of vascular targeting antitumor drugs.

Toxoplasma gondii is a globally important zoonotic pathogen that causes widespread infections in both human and animal populations. Current pharmacological treatments for toxoplasmosis are plagued by considerable limitations, highlighting the urgent demand for novel therapeutic agents with hight efficacy and low toxicity. β-carboline (βC) alkaloids, due to their inherent biological activities, represent promising candidates with substantial therapeutic potential. In this study, we designed and synthesized a novel β-carboline derivative, H-168-B, and systematically evaluated its anti-T. gondii activity through both in vitro and in vivo experiments. In vitro assays revealed that H-168-B exhibited relatively low cytotoxicity in Vero cells (cell viability >90%) and effectively inhibited the proliferation of T. gondii tachyzoites (IC₅₀ = 34.52 μM). Additionally, plaque assays conducted in HFF cells showed a dose-dependent decrease in plaque formation, with near-complete inhibition observed at 100 μM. This concentration also significantly impaired parasite invasion and intracellular replication. In an infected ICR mouse model, H-168-B treatment stabilized body weight, extended mouse survival time by 30%, and exerted moderate organ-protective effects compared with sulfadiazine. Collectively, these results identify H-168-B as a promising novel anti-parasitic compound warranting further investigation.