Compared with traditional structure-based approaches for the identification of species-specific ligands, the ab initio approach, based on large-scale protein sequences from different species, has been used to locate specific sites that may be important to the molecular selectivity of species. Statistically significant differences in the distribution of residues in different species and differences in the physicochemical properties of residue-specific sites may largely account for species selectivity. The nicotinic acetylcholine receptor (nAChR), an important neuro-receptor with significantly different ligand selectivity in different species, was used to test our method. Because of the lack of nAChR structural information, the mechanism of ligand discrimination is unclear which hinders attempts at novel molecular design. In this study, the specific site residues 186 and 189 in the principal subunits and residues 34, 55, 56, 57, 106 and 112 in complementary subunits of nAChR were identified by applying our method with stringent statistical cutoffs. These sites were predicted to contribute to ligand selectivity and this result coincides well with the known experimental data.
The crystal structure of the new title compound 3-（4-chlorophenyl）-8-cyano-2-（di-iso-propylamino）-5-methyl-7-（methylthio）-pyrido[4,3-d]pyrimidine-4（3H）-one（C22H24ClN5OS,Mr = 441.97）has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic,space group Pna21 with a = 7.6721（5）,b = 18.9370（11）,c = 15.6260（9）A,V = 2270.2（2）A^3,Z = 4,Dc = 1.293 g/cm^3,F（000）= 928,μ = 0.283 mm^-1,MoKa radiation（λ = 0.71073 A）,R = 0.0494 and wR = 0.1062 for 3278 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the py-ridopyrimidinone moiety are almost coplanar. Intramolecular C（20）-H（20）···N（4）,C（19）-H（19A）···N（3）,C（18）-H（18C）···N（3）and C（16）-H（16B）···O（5）hydrogen bonds together with weak C···π interactions are found in the structure.
Started from salicylic acid（SA） and related commercialized plant activators,based on molecular threedimensional shape and pharmacophore similarity comparison（SHAFTS）,a new lead compound benzotriazole was predicted and a series of benzotriazole derivatives were designed and synthesized.The bioassay showed that benzotriazole had high activity against a broad spectrum of diseases including fungi and oomycetes in vivo,but no activity in vitro.And the introduction of proper groups at the1＇-position and 5＇-position was beneficial to the activity.So,they had the potential to be exploited as novel plant activators.
选择硫脲为起始原料,与溴乙酸乙酯一步反应生成2-亚氨基-4-噻唑烷酮(2),与苯甲醛缩合得2-氨基-5-苯甲叉基-4-噻唑酮(3),再与取代苯甲酰氯反应,合成了7个未见文献报道的噻唑酮类化合物.通过IR,1 H NMR,13 C NMR和元素分析对目标化合物进行了结构鉴定,测定了它们的抗肿瘤活性和杀菌活性.结果表明:部分测试化合物对肿瘤细胞KB和CNE2有一定的抑制作用,化合物4a对6种病菌都有不同程度的抑制活性.
The 1,2,3-thiadiazole-carboxylate moiety was reported to be an important pharmacophore of plant activators.In this study,a series of novel plant activators based on thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate were designed and synthesized and their biological activity as plant activators was studied.The structures of the novel compounds were identifed by1H NMR,19F NMR and HRMS.The in vivo bioassay showed that these novel compounds had good effcacy against seven plant diseases.Especially,compounds 1a and 1c were more potent than the commercialized plant activator BTH.Almost no fungicidal activity was observed for the active compounds in the in vitro assay,which matched the requirements as plant activators.
A new crystal of 4-fluoro-N-（2-methyl-5-（（2-（p-tolyloxy）acetamido）methyl）pyrimi- din-4-yl）benzamide has been prepared at room temperature and characterized by 1H NMR, 13C- NMR, IR, MS, elemental analysis and X-ray single-crystal determination. The compound crystallizes in monoclinic, space group P21 /c with a = 17.226（5）, b = 13.934（4）, c = 17.262（5）, μ= 92.180（5）°, V = 4140（2） ？3, Dc = 1.311 g/cm3, Z = 8, F（000） = 1712 and ？？= 0.095 mm-1. The molecular packing in the crystal is the result of N-H…ydrogen bonds.
