Yufang He

Synthesis, characterization and cytotoxicity of new rotundic acid derivatives.

Rotundic acid (RA, 1), a natural compound, exhibits potent tumor cell growth inhibiting properties. To date there are no reports on derivatives of RA. Furthermore, the 28-COOH position of RA might make it unstable and induced serious gastrointestinal side effects when it was applied in vivo. Therefore, in order to explore and make use of this compound, eight new amino acid derivatives of RA at the 28-COOH position were synthesized and evaluated for their cytotoxicities in vitro on three tumor cell lines including A375, HepG2 and NCI-H446. As a result, a few of these new amino acid derivatives showed stronger cytotoxicity. Compound 5a was found to have the best inhibition activity on the three tested human tumor cell lines with IC50 values of less than 10 μM compared with RA treatment. Meanwhile, the cytotoxicity of compound 6b was significantly higher than that of RA on the A375 cell line and almost the same as RA on the HepG2 and NCI-H446 cell lines. Hence, compounds 5a and 6b may serve as potential lead compounds for the development of new anti-tumor drugs.

Novel rotundic acid derivatives: Synthesis, structural characterization and in vitro antitumor activity

Six novel rotundic acid (RA, 1) derivatives 4a-4f modified at the 28-COOH position were synthesized, and their structures were confirmed by IR, MS, 1H NMR and 13C NMR. The derivatives were evaluated for cytotoxic properties on the following three tumor cell lines: HeLa, HepG2 and SGC-7901. Compound 4f showed better cytotoxic activity compared with RA treatment and lower IC50 (4.16 µM) on HepG2 cells than on HeLa (8.54 µM) and SGC-7901 cells (11.32 µM). The anticancer mechanism of compound 4f was studied through cell cycle progression and apoptosis. Notably, compound 4f was able to induce apoptosis and G0/G1 cell cycle arrest of HepG2 at a concentration of 4.16 µM. In summary, RA was modified to obtain six novel derivatives. Compound 4f exhibited better cytotoxicity and may be developed as a potential agent against hepatocellular carcinoma.

Design, synthesis and cytotoxicity of cell death mechanism of rotundic acid derivatives

In the present investigation, 16 new rotundic acid (RA) derivatives modified at the C-3, C-23 and C-28 positions were synthesized. The cytotoxicities of the derivatives were evaluated against HeLa, A375, HepG2, SPC-A1 and NCI-H446 human tumor cell lines by MTT assay. Among these derivatives, compounds 4-7 exhibited stronger cell growth inhibitory than RA and compound 4 was found to be the best inhibition activity on five human tumor cell lines with IC50 <10 μM. The apoptosis mechanism of compound 4 in HeLa cells was investigated by western blot analysis. The results indicated that compound 4 could induce apoptosis through increasing protein expression of cleaved caspase-3 and Bax, and decreasing protein expression of Bcl-2. In summary, the present work suggests that compound 4 might serve as an effective chemotherapeutic candidate.

Design, synthesis and evaluation of antitumor activity of new rotundic acid acylhydrazone derivatives.

Abstract In light of the important antitumor activity of acylhydrazone compounds and based on our previous study, 18 new rotundic acid (RA) acylhydrazone derivatives were synthesized. All of the compounds were characterized by their spectroscopic data. The antiproliferative activity of the compounds was evaluated in vitro via the MTT method in three tumor cell lines, including A-375 (human malignant melanoma cells), SPC-A1 (human lung adenocarcinoma) and NCI-H446 (small cell lung cancer). The results showed that the antiproliferative activity of all of the compounds on the NCI-H446 cell line did not increase compared to RA, however, most of the derivatives exhibited higher activity against the A375 and SPC-A1 cell lines as compared to RA. Importantly, the antiproliferative activities of compounds 5a and 5b were the highest among the compounds, with IC50 values <10 μM. Collectively, compounds 5a and 5b may act as potential anti-tumor agents in the future.