钨钼杂多酸及其盐与二甲基亚砜加合物的制备和性质研究

在乙腈和水的混合溶剂中制备了9种钨钼杂多酸和杂多酸盐的二甲基亚砜加合物。研究结果表明,加合物中杂阴离子的Keggin结构基本不变。配体DMSO以S=O键上的氧作为配位原子,它不直接与杂阴离子骨架结构发生配位作用,而是与杂多酸中的质子氢或杂多酸盐中的金属阳离子以氢键或配位键相配位,生成的质子(钅羊)离子和金属配离子再通过离子缔合键与杂阴离子相结合,形成杂多酸或杂多酸盐加合物。     

Synthesis and properties of poly(oxyethylene)s containing thioether,sulfoxide, or sulfone groups

Poly[oxy(ethylthiomethyl)ethylene] (ETE) was prepared from poly[oxy (chloromethyl)ethylene] (CE) by reaction with sodium ethanethiolate. Sulfoxide and sulfone analogues were synthesized by oxidation of the poly[oxy(ethylthiomethyl)ethylene]. By changing the chloromethyl/sodium ethanethiolate ratio, poly[oxy (chloromethyl)ethylene-co-oxy(ethylthiomethyl)ethylene] (CE-ETEs) were easily made. Poly[oxy(ethylsulfinylmethyl)ethylene] (ESXE), poly[oxy(chloromethyl)ethylene-co-oxy(ethylsulfinylmethyl)ethylene] (CE-ESXEs), poly[oxy(ethylsulfonylmethyl)ethylene] (ESE), and poly[oxy(chloromethyl)ethylene-co-oxy(ethylsulfonylmethyl)ethylene] (CE-ESEs) were obtained by oxidation of ETE or CE-ETEs. There was little if any chain degradation. The (co)polymer structures were confirmed by FTIR and ¹H-NMR spectroscopic studies. Their thermal properties were studied by DSC and TGA. T_gs of ETE, ESXE, and ESE were -57, 36, and 57°C, respectively, and T_d,os (initial decomposition temperature, TGA) were 331, 198, and 308°C, respectively. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 793–801, 1998     

Multicomponent Synthesis of 2-(2,4-Diamino-3-cyano-5H-chromeno[2,3-b]pyridin-5-yl)malonic Acids in DMSO

Dimethyl sulfoxide is a widely used solvent in organic synthesis and in the pharmaceutical industry because of its low cost, stability, and low toxicity. Multicomponent reactions are an advanced approach that has become an efficient, economical, and eco-friendly substitute for the conventional sequential multi-step synthesis of various biologically active compounds. This approach was adopted for the synthesis of previously unknown 2-(2,4-diamino-3-cyano-5H-chromeno[2,3-b]pyridin-5-yl)malonic acids via transformation of salicylaldehydes, malononitrile dimer, and malonic acid. It was shown that the use of DMSO at room temperature makes it possible to synthesize previously unavailable compounds. The investigation of the reaction mechanism using ¹H-NMR monitoring made it possible to confirm the proposed mechanism of the transformation. The structure of synthesized 5H-chromeno[2,3-b]pyridines was confirmed by 2D-NMR spectroscopy.     

Synthesis,spectroscopic study,X-ray diffraction,and comparative antimicrobial study of Schiff bases based on o-toluidine and their Co(II) complexes

Schiff bases are versatile compounds for the design of the ternary complex. An experiment has been made to synthesize two novel complexes of Co(II). Here, The primary ligand, L₁ was prepared by the condensation reaction of o-toluidine with 3-formyl chromone or o-toluidine with 3- methylquinolinecarbaldehyde and the secondary ligand which was 8-Hydroxyquinoline. These potent complexes were prepared by condensation of primary and secondary ligands with Cobalt salt. The reaction was performed through the conventional reflux method. The newly synthesized chromone and quinoline derived novel compounds are proposed to have significant antimicrobial activity against selective strains of bacteria and fungi. This can be great opportunity for researchers and the use of biological applications of the synthesized novel compounds can be a part of unique field of research for the future to be focus. Chromone derivative has great biological diversity in the medicinal and pharmaceutical fields. Along with these compounds, quinoline derivatives also have antibacterial, and antifungal activities. The synthesized ligand and complex were characterized by elemental analysis, molecular weight determination, magnetic moment measurement, melting point determination, spectral analysis (IR, UV–Vis, ¹H NMR, Mass, etc.), and X-ray diffraction. The synthesized complexes were paramagnetic and non-electrolytic in nature. The Uv–Vis, FTIR, NMR, and Mass spectra suggest the octahedral geometry of the complexes. The synthesized compounds were further evaluated for biological studies against selected bacterial and fungal strains. It has been observed that the antimicrobial activity of most of the complexes are better than that of ligands.     

2-Ketophenyl Assisted Biomimetic Synthesis of 3-Thio Substituted Glycals at Room Temperature

Herein we designed a strategy for the synthesis of regioselective and stereoselective displacement of C-3 acetate group in the presence of other C-4 and C-6 acetate of 2-ketophenyl-glycal by different aromatic and cyclic aliphatic thiol nucleophiles taking inspiration from cytosolic esterase mediated thiolation of glucosamine sugars into cellular glycan. Under a mild base condition at room temperature, the protocol generated a library of 3-arylthiosugars with excellent yields and high axial selectivity. This stereoselective approach tolerated well with different ester-protected glycals and thiophenols, aliphatic cyclic thiols, and mercaptans. A variety of control experiments were conducted to establish the mechanism and reason behind the stereoselectivity.     

Polyphenolic characterization and evaluation of multimode antioxidant,cytotoxic, biocompatibility and antimicrobial potential of selected ethno-medicinal plant extracts

IntroductionScientific evidence about biological profile of natural products can support their traditional uses. The current work was aimed to assess phytochemical and biological profile of nine medicinal plants collected from Herbalists.MethodsExtracts prepared in different solvents were subjected to phytochemical, antioxidant, enzyme inhibitory, cytotoxic, and antimicrobial activities. Reverse phase-high performance liquid chromatography (RP-HPLC) analysis was performed for the quantification of polyphenols.ResultsResults showed methanol extract (M) being potent as compared to others. Gentian lutea M showed maximum extract recovery (15.00 ± 0.11 % w/w) and TFC (30.82 ± 0.21 μg QE/mg extract). Nigella sativa M displayed highest TPC (44.99 ± 0.43 μg GAE/mg extract) and TAC (334.72 ± 0.35 μg AAE/ mg extract). Results showed noteworthy quantities of vanillic acid, rutin, kaempferol, emodin in ethyl acetate (EA) and methanol (M) extracts of plants assessed by RP-HPLC. Gentisic acid was highest (11.75 µg/mg extract) in T. arjuna M extract. Similarly, maximum %FRSA (82.28 ± 0.03 %) and TRP (160.40 ± 0.38 μg AAE/ mg extract) were depicted by Terminalia chebula and Chamomilla recutita, respectively. Moreover, Mentha longifolia and G. lutea M demonstrated noteworthy (p < 0.05) antibacterial activity against Staphylococcus aureus (14 ± 0.7 mm) and Klebsiella pneumoniae (12 ± 0.3 mm), respectively. Curcuma amada, C. recutita, Murraya koenigii and G. lutea M had significant α-glucosidase activity. Another good solvent for extraction was ethyl acetate (EA), whose extracts were secondary to methanol in producing significant biological profile. For example, EA of N. sativa (TPC: 1.46 ± 0.45 µg GAE/ mg extract), G. lutea (TRP: 160.33 ± 0.52 μg AAE/mg extract: ZOI of 12 ± 0.5 mm in K. pneumoniae) and Mormodica charantia (α-amylase inhibition: 39.5 ± 0.10 %) showed significant bioactivities. All extracts displayed mild antifungal protein kinase inhibition activities and were significantly (greater than80 %: p < 0.05) cytotoxic to brine shrimps with negligible hemolytic activity.ConclusionBriefly, variable polarity solvent extracts of studied plants will be processed for isolation of antioxidant, cytotoxic, carbohydrate enzyme inhibitory and antibacterial compounds.     

Enhanced skin anti-inflammatory and moisturizing action of gold nanoparticles produced utilizing Diospyros kaki fruit extracts

Inflammatory skin diseases (ISD) cause very severe itchy skin and dryness which is now a days an important issue which has to be taken care. Nanotechnology plays a main role in manufacturing cosmetic ingredients at a nanoscale size. Among different nanoparticles, gold (Au) is one of the non-toxic materials synthesized organically or inorganically. For synthesizing nanoparticles (NPs), using inorganic methods may cause some toxicity to cells, but using organic synthesis like plant extract is less toxic and environmentally friendly. Therefore, we synthesized DK-AuNPs using Diospyros kaki fruit extract. UPLC-MS/MS was used to evaluate phytochemicals responsible for converting salt into nanoparticles. The DK-AuNPs were characterized to confirm the formation of NPs. Furthermore, we analyzed the activity of DK-AuNPs on human keratinocytes (HaCaT cells). The DK-AuNPs showed 98.2 % cell survival upto 200 µg/mL against HaCaT cells. Additionally, compared to DK treatment, DK-AuNPs therapy decreased ROS production in TNF-α/IFN-γ (T + I) stimulated HaCaT cells by 68.7 %, whereas DK treatment reduced ROS generation by 27.8 %. Moreover, the skin anti-inflammatory potential and moisturizing effect of DK-AuNPs were analyzed using HaCaT cells. Furthermore, skin inflammatory activity biomarkers were downregulated through the MAPK/NFκB signaling pathway and showed significant inhibition by DK-AuNPs. Also, the skin moisturizing biomarkers such as HAS (1–3) were upregulated and HYAL (1–2) were downregulated by PI3K/AKT/NFκB through HAS2 regulation. Therefore, skin anti-inflammatory and moisturizing activity were enhanced by treatment with DK-AuNPs. In summary, we conclude that the DK-AuNPs could be a new alternative for skin disease.     

Synthesis and characterization of copolymers of β-cyclodextrin derivatives

Cyclodextrins (CDs) are cyclic oligosaccharides made up of d-glucose units connected by 1,4-glucosidic linkages. β-CD is a cyclical starch derivative containing seven glucopyranose units. β-CD derivatives have characteristic property of larger surface area, robust mechanical strength, high surface to volume ratio, electrical and optical properties for analyte determination, good dispersion, easy removal of the template, surface modification, functionalization and handling capacity. In this work, an attempt is made to prepare succinyl-β-CD-acrylamide (S-β-CD-AA) copolymer and β-CD-malic anhydride (β-CD-MAH) copolymer. For the synthesis of S-β-CD-AA, S-β-CD derivative is prepared and further, acrylamide (AA) along with cross-linker undergoes free radical copolymerization for the formation of gel like product. The degree of succinylation (DS) of β-CD derivative is estimated. S-β-CD-AA copolymer showed potential swelling, and deswelling characteristic. Another copolymer is prepared from β-CD malic anhydride derivative. Further, the derivative is treated with cellulose and ethylene diamine tetra acetate (EDTA) to form β-CD-MAH copolymer. The two derivatives are characterized by several techniques. Thermal stability of these copolymers is estimated with the help of thermogravimetric analysis. The basic characterization of the presence of functional groups is done using UV–visible spectroscopy, and infrared spectroscopy. The elemental analysis helped to estimate C, H, N, S in the synthesized compounds. The surface morphology characterization is done with the help of scanning electron microscopy. X-ray diffraction analysis helped in determination of crystal structure of β-CD-MAH. β-CD derivatives prepared may be potential candidate to prepare inclusion complex, in drug delivery, drug loading and several similar applications.