Uvarmicranones A and B, two new benzoquinones and cytotoxic constituents from the stems of Uvaria micrantha (A. DC.) Hook. f. & Thomson

Design, synthesis, and evaluation of new anti-inflammatory natural products amide derivatives endowed with anti-blood cancer activity towards development of potential multifunctional agents against hematological cancers

New amide derivatives of the natural product 5,6,7-trimethoxyflavanone were designed as multifunctional antiproliferative molecules against blood cancer and the associated inflammatory conditions. The targeted compounds were synthesized efficiently in three linear steps employing known chalcone starting materials. Compounds 2h, 2i, 2l, 2t, 2v and 2x having bromo or nitro substituted-phenyl rings elicited potential inhibitory effects on macrophages production of nitric oxide, PGE₂ and TNF-α which are proinflammatory mediators involved in tumorigenesis and progression of blood cancer. Additionally, evaluation of direct inhibitory effects on the growth of diverse blood cancers including leukemia, lymphoma, and myeloma cell lines unveiled compound 2v as the most potential molecules eliciting at least five-folds the potency of the standard imatinib drug over the used diverse blood cancers. Furthermore, compound 2v showed good selectivity to blood cancer cells rather than normal MRC5 cells. Moreover, compound 2v triggered death of HL60 leukemia cells via apoptosis induction. In conclusion, the natural product-derived compound 2v might serve as a multifunctional lead compound for further development of agents for treatment of blood cancers.

Acetogenins from the stems of Uvaria micrantha showing antiproliferative effects on HepG2 liver cancer cells

Five mono-tetrahydrofuran acetogenins: uvamicranins A-E and three known mono-tetrahydrofuran acetogenins; reticulatacin, calamistrin A, and uvarigrin, were isolated from the stems of Uvaria micrantha (Annonaceae). Their structures were elucidated by 2D NMR and high-resolution mass spectral analysis. The absolute configurations of uvamicranins A and B were determined by modified Mosher's method. Evaluation of antiproliferative activity of the isolated compounds showed that they were more potent towards the human hepatocellular carcinoma cell line HepG2, compared to the five other tested cell lines. Among the tested compounds, uvamicranin B (UvB) and uvarigrin (Uv) possessed strong antiproliferative activity with IC50 values of 2.89 ± 0.71 μM and 0.37 ± 0.06 μM, respectively. The antiproliferative mechanism of UvB and Uv, was investigated in HepG2 cell line showing that both compounds marginally induced apoptotic cell death, but exhibited cytostatic effect through induction of cell cycle arrest at the G2/M phase.