Volume 23, Issue 5

The genus Saussurea (Asteraceae) contains about 400 species distributed around Asia and Europe and used in the traditional medicines of many cultures. The main compounds isolated from Saussurea species are terpenoids, in particular, sesquiterpenoids are dominant. This review lists 404 chemical constituents as well as their biological activity (111 references).

S -[(4,5-dihydro-1 H -imidazol-2-yl)methyl]sulfothioate, a new imidazoline-containing Bunte salt 4 was prepared by reacting 2-chloromethylimidazoline 3 with sodium thiosulfate in aqueous solution at room temperature. The mechanism of the concerted S N 2 reaction pathway was studied by means of quantum chemical calculations at the B3LYP/6-31G** level of theory. The molecular structure of compound 4 incorporating a formal amidine moiety was confirmed by single crystal X-ray diffraction analysis, while its electronic structure was studied using quantum chemical calculations at the MP2/6-311++G** level of theory.

Reaction between substituted thiazolylamine or oxazolylamine, triethyl orthoformate and sodium azide in the presence of tributylmethylammonium chloride in DMSO furnishes 1-substituted 1 H -1,2,3,4-tetrazole in high yield.

A new, simple method for the synthesis of 4 H -1,3,5-oxadiazine derivatives was developed based on the dehydrogenation reaction of N -amidoalkylated thioureas with dicyclohexylcarbodiimide. The reaction was carried out in acetonitrile under reflux for 50–60 min. The precipitated products were easily purified by crystallization from acetonitrile or ethanol. The yields were 30–70%. The structure of the synthesized compounds was determined by IR, 1 H NMR, 13 C NMR, MS and X-ray crystallography.

A convenient method for the synthesis of spiro[indeno[1,2- b ]quinoxaline-[1,3,4]oxadiazole]s involves a 1,3-dipolar cycloaddition reaction of nitrile imines generated in situ with indenoquinoxaline derivatives.

A facile one-pot synthesis of spirooxindolinopyrrolizidines incorporating the pyrene moiety was accomplished in good yields through a 1,3-dipolar cycloaddition reaction of 3-aryl-1-(pyren-1-yl)prop-2-en-1-one derivatives with in situ -generated azomethine ylides.

Benzene-1,2-diamine was treated with 2-nitrobenzaldehyde in EtOH, and the product was reduced with hydrazine hydrate in the presence of Fe(C) without separation to give 2-(1 H -benzo[ d ]imidazol-2-yl)aniline ( 1 ). Reactions of compound 1 with isatins in the presence of iodine in an ionic liquid furnished 5 H -spiro[benzo[4, 5]imidazo[1,2- c ]quinazoline-6,3′-indolin]-2′-ones in high yields.

A novel benzothiazole-functionalized Schiff-base derivative L was prepared and its metal-ion sensing properties were investigated. Sensor L displays selective naked-eye color change from yellow to green in the presence of Cr 3+ in aqueous solution at pH 7.2, while other cations do not interfere with the recognition of Cr 3+ . The proposed mechanism is supported by Job’s plot evaluation, IR and ESI-MS studies. The association constant and detection limit of sensor L to Cr 3+ are 5.73×10 4 m −1 and 2.1×10 −8 m , respectively. A B3LYP/6-31G (d,p) basis set was employed for optimization of L and L -Cr 3+ complex.

This study reports the acid-base properties of taxifolin (Tf) in HCl media and aqueous complexation with Ni(II). The equilibrium processes was investigated using a spectrophotometric technique and ab initio calculations. Equilibrium constant of protonation was determined using a non-linear Cox-Yates method. Analysis of Ni(II)-Tf complex species under metal dominance conditions was performed in tris-buffer solution. For interpretation and verification of experimental results the Def2-SVP/DFT/PBE0/SMD level was used.

Zirconium oxide nanoparticles are an efficient catalyst for the preparation of 1 H -pyrazolo[1,2- b ]phthalazine-5,10-diones via a three-component reaction of phthalhydrazide, aromatic aldehydes and malononitrile under solvent-free conditions.

New 4,4′-(4,6-dimethoxy-1,3-phenylene)-bis( N -substituted thiazol-2-amine) derivatives 5a–j were synthesized from 1,1′-(4,6-dimethoxy-1,3-phenylene)-bis(2-bromoethanone) 3 and substituted thioureas 4a–j under conventional and microwave irradiation conditions. All products were subjected to in vitro antibacterial and anti-TB evaluation. Some of the compounds exhibit good activities against Bacillus subtilis (+ve), Escherichia coli (−ve) strains and Mycobacterium tuberculosis H37Rv.