Novel Gomisin B analogues as potential cytotoxic agents: Design, synthesis, biological evaluation and docking studies.

As part of pharmacological-phytochemical integrated studies on medicinal flora, Gomisin B (1) was isolated as major phytochemical lead from schisandra grandiflora, a plant traditionally used in different Asian systems of medicine. A series of 1,2,3-triazoles derivatives were synthesized at the C-7' position of the gomisin B core through diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5q) were well characterized using modern spectroscopic techniques and evaluated for their anti-cancer activity against a panel of five human cancerous cell-lines. Among them, compound 5b exhibited the best cytotoxicity against SIHA cell (IC50 0.24 µM) which was more than the standard drug doxorubicin, while the other derivatives were exhibited moderate to low activities in tested cell lines. The cell cycle analysis indicated that compound 5b stalled HeLa cells at G2/M phase. 5b promoted tubulin polymerization and this was supported by the docking studies, wherein 5b showed significant binding affinity at the colchicine binding pocket of tubulin. Overall, we identified a novel small molecule that demonstrated anticancer activity by promoting in vitro tubulin assembly.

Advanced glycation end-products inhibitors isolated from Schisandra grandiflora.

Free radicals scavenging and advanced glycation end-products (AGEs) inhibitory potentials in crude chloroform extract of Schisandra grandiflora were evaluated. Bioassay-guided isolation of the chloroform extract led to the identification of 24 compounds. Among the isolates, ( ± ) gomisin M1, arisantetralone C and D, macelignan, saurulignan B and SZ-MO displayed potent-free radical scavenging as well as AGEs inhibitory potentials. This is the first report identifying the presence of AGEs inhibitory activity and assigning AGEs inhibitory activity to these compounds. Therefore, our research finds new application of traditional medicinal plant S. grandiflora having capacity to reduce formation and accumulation of AGEs in diabetes.

Novel sesquiterpenes from Schisandra grandiflora: isolation, cytotoxic activity and synthesis of their triazole derivatives using "click" reaction.

Phytochemical investigation of hexane extract from the fruits of Schisandra grandiflora afforded three novel sesquiterpenes (1-3) along with the three known compounds (4-6). The structures of these isolates were determined by extensive analysis of spectroscopic data (1D, 2D NMR). Further, a series of triazole analogues of 3 and 4 were prepared using "Click" reaction protocol. The reaction scheme involving one-carbon homologation of 3 and 4 using the Bestmann-Ohira reagent followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction of various azides leading to the formation of triazole analogues (20a-20k &21a-21c) which is being reported for the first time. All the triazole products were characterized using spectral data analysis. The anti-proliferative activity of the isolates and the synthetic analogues were studied against Hela (Cervical cancer), A549 (Lung cancer), DU-145 (Prostate cancer), MCF-7 (Breast cancer) and B-16 (Mouse melanoma) cancer cell lines.

Phytochemical investigation of sesquiterpenes from the fruits of Schisandra chinensis and their cytotoxic activity.

Phytochemical investigation of ethanolic extract from the fruits of Schisandra chinensis led to the isolation of four new sesquiterpenes (1-4); their structures were determined by a combination of NMR (1D and 2D) and MS spectroscopic techniques. In addition, all these isolates were screened for their cytotoxic activities against MCF-7, Caco-2, Hela, Lncap, Hep G2 and MDA-MB231 cancer cell lines. Results indicated that compounds 2 and 3 displayed potent cytotoxic activity against Caco2 cell lines with IC50 values of 17.10 µg/mM and 16.46 µg/mM, respectively.

Methyl angolensate and mexicanolide-type limonoids from the seeds of Cipadessa baccifera.

Six new methyl angolensate type (1-6) and three new mexicanolide-type (7-9) limonoids, along with six known limonoids (10-15), were isolated from the seeds of Cipadessa baccifera. The structures of all these compounds were established by extensive 1D, 2D NMR, and HRESIMS experiments, and structures of 11 and 13 were further confirmed by a single crystal X-ray diffraction analysis, which are reported for the first time. The cytotoxic activities of these isolates were also studied against A549, MCF7, ME-180, HT-29, B-16, ACHN cancer cell lines using MTT assay, and results indicated that compounds 4, 10, and 14 displayed potent cytotoxic activity against B-16, ACHN cell lines with an IC50 values of 8.51 and 7.0 µg/mL, respectively.