Design, Synthesis And SAR Study Of Analogues Of Stilbenoids And Chalcone

Stilbene derivatives are widely distributed in nature, which are thought to be phytoalexins. There is a growing interest in stilbene derivatives because many activities have been observed in some of the naturally occurring as well as some of the synthetic stilbenes. Activities include antitumor, anti-allergic, antileukemic, anti-platelet aggregative, inhibition of SARA coronavirus replication, anti-inflammatory, anti-HIV, antibacterial, anti-herpes simplex virus, and antioxidant. In plants, the stilbenes play important roles, especially in heartwood protection as part of both constitutive and inducible defense mechanisms, and in dormancy and growth inhibition. Certain stilbenoids, besides being toxic to insects and other organisms, have mammalian antifeedant and nematicidal properties. In this paper, we synthesized a series of stilbene derivatives and their antifeedant activity toward the third-instar larvae of Brontispa longissima were tested, and studied the preliminary structure-activity relationships of these stilbenes. The results showed that compounds 2-4g,2-4b and 2-7 had effective antifeedant activities with AFC50 values of 0.218, 0.327 and 0.226 mg/mL respectively. And the results revealed that different structural variations attached to the stilbenoid ring had different antifeed activities against Brontispa longissima. And some important SAR information has been revealed. Further investigation on the 3D QSAR model was carried out using CoMFA analysis.In addition, chalcones (1,3-diaryl-2-propen-1-ones) constitute an important class of natural products belonging to the flavonoids family and some of them possess anticancer, antimalarial, antiinflammatory, and antimicrobial activities. In this paper, a series of substituted chalcones were synthesized. we firstly evaluated antibacterial activities of the chalcone derivatives against Mango stem end rot pathogen and Colletotrichum gloeosporioides on mango fruit and studied the preliminary structure-activity relationships of these chalcones. The results showed that compound 4-3-3 and 4-3-15 had effective inhibition against Colletotrichum gloeosporioides on mango fruit with inhibition rate 81.9% and 88.60% respectively. Compound 4-3-10 and 4-3-26 had very high inhibition against Mango stem end rot pathogen with inhibition rate 90.56% and 86.35%, respectively. And the same time, the structure-activity relationships of the chalcone derivatives had been also discussed. The above results not only lead to a better understanding of structural requirements of antifeedant and antibacterial activities but also can help in the design of novel compounds with enhanced activity.