Synthesis and Biological Evaluation of 3,5‐Dimethoxystilbene Analogs

Abstract

In our continuing effort to discover natural product-based pest management agents, derivatives of 3,5-dimethoxystilbene were synthesized yielding 27 new and six known compounds. Compounds 11 and 12 showed strong Aedes aegypti larvicidal activity (LC 45.31 and 49.93 μm, respectively). Furthermore, 11 and 12 exhibited high effectiveness against larvae of pesticide-susceptible and pyrethroid-resistant strains of Ae. aegypti; activity against the adult mosquitoes was low. Compounds 6f, 6g, and 6i at either 83.3 or 166.7 μg/ml reduced the mobility of second-stage juveniles (J2) of the root-knot nematode (Meloidogyne incognita) that hatched from eggs immersed in the test compounds for 7 days. However, there was little or no effect on J2 placed directly into these compounds, and none of the analogs suppressed M. incognita egg hatch. The compounds were tested for inhibition of some agriculturally important fungi; 6a, 7a, and 7e demonstrated strong inhibition of Colletotrichum species. Activity of the stilbenes against some human pathogens was also explored; 11, 12, and 16 showed moderate inhibitory activity against Cryptococcus neoformans, Staphylococcus aureus, methicillin-resistant S. aureus, and Mycobacterium intracellulare. Except for 11 and 12, which were active against mosquito larvae and some human pathogens, no single analog demonstrated activity in all the tests, indicating specific activities. Synthesis of the analogs and structure-activity relationships are discussed.

Design, Synthesis and Cytotoxicity of Thiazole-Based Stilbene Analogs as Novel DNA Topoisomerase IB Inhibitors

“…All the target compounds were identified and characterized by 1 H-NMR, 13 C-NMR and ESI-HRMS. In the 1 H-NMR spectra of the target compounds, the signals of the vinylic CH proton connected to the thiazole ring were observed at around 6.93–7.38 ppm, and the peaks of the vinylic CH proton connected to the benzene ring appeared in the 7.10–7.64 ppm range, generally appearing as a doublet with a coupling constant J = 16.0 Hz or 16.5 Hz, which indicated that the target compounds are of the E -configuration [ 30 ]. In the 13 C NMR spectra, the signals of the vinylic carbon adjacent to the thiazole ring could be found at around 119.3–124.6 ppm, and the peaks of the vinylic carbon adjacent to the benzene ring were observed in the range of 130.8–137.9 ppm.…”

SK-03-92 Drug Kills Intracellular Mycobacterium tuberculosis

“…Tamoxifen (a phenylstilbene compound) is being explored as an anti-mycobacterial drug, acting as a host-directed therapeutic that assists macrophages in killing mycobacterial cells [ 19 , 20 , 21 ]. Analogs of 3,5-dimethoxystilbene had MIC values that ranged from 61.68 and 74.04 μg/mL against M. intracellulare [ 22 ]. The 3-fluoro-Z-stilbene exhibited an MIC of 26 μg/mL against M. bovis [ 23 ].…”