茶皂素―金属复合抗菌剂的制备及抗菌性能研究

通过抑菌环法探讨了茶皂素、金属离子、茶皂素―金属复合抗菌剂对大肠杆菌和金黄色葡萄球菌的抗菌活性,考察了茶皂素纯度、浓度、金属离子种类等因素对抗菌剂抗菌活性的影响。结果表明,茶皂素的抗菌活性与单一的金属离子的抗菌活性相当,茶皂素对大肠杆菌的最低抑制浓度为5 mg/mL,对金黄色葡萄球菌的最低抑制浓度是10 mg/mL;茶皂素与金属离子复配抗菌活性具有协同效应,尤其茶皂素―锌复合抗菌剂对大肠杆菌的抑制效果大大加强。     

Synthesis and Biological Activity of 3-[4H-(1,2,4)-Triazolyl]-2,6-diaryl-1,3,5-oxadiazine-4-thione

4-Amino-1,2,4-triazole (1) undergoes facile condensation with aromatic aldehydes to afford the corresponding 4-(arylidene-amino)-4H-[1,2,4]-triazole (2a–h) in good yield. Rearrangement of compounds (2a–h) with benzoyl isothiocyanate/4-chloro-benzoyl isothiocyanate/2,4-dichloro-benzoyl isothiocyanate yields corresponding 1,3,5-oxadiazine derivatives (3). Structural elucidation of these compounds was based on elementary analysis and spectral data studies. The newly synthesized compounds were evaluated for their antibacterial activities.     

Synthesis of Some 2-(3-Alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles as Novel Antibacterial Agents

Abstract

Herein, we describe a one-pot synthesis of some novel 2-(3-alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles (6) involving the reaction of 3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazole-1-thiocarboxamides (3) with 3-bromoacetylcoumarins (5) in the presence of sodium carbonate in ethanol. Reaction of 3 with 5 in the absence of sodium carbonate, however, resulted in the formation of 2-(3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazol-1-yl)-4-(coumarin-3-yl)thiazoles, which were subsequently dehydrated to 6 by refluxing in ethanol in the presence of sodium carbonate. The structure of the synthesized compounds (6) was confirmed by infrared (IR), mass, ¹H NMR, and ¹³C NMR spectra and elemental analysis data. Newly synthesized compounds (6) showed moderate to good activity against Gram-positive bacteria.     

Synthesis, Crystal Structure and Antibacterial Activity of Two Hydrazones Derived from 2-Fluorobenzhydrazide

Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 (Ⅰ) and C14H10F2N2O (Ⅱ), have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds crystallize in monoclinic, space group P21/c with a = 7.0514(14), b = 25.928(5), c = 7.7099(15), β = 111.823(2)°, V = 1308.6(4)3, Z = 4, C14H10FN3O3, Mr = 287.25, Dc = 1.458 g/cm3, μ(MoKα) = 0.115 mm-1, F(000) = 592, the final R = 0.0841 and wR = 0.2489 for 1901 observed reflections (I > 2σ(I)) for I; a = 11.232(3), b =12.735(4), c = 8.612(2) , β = 90.869(3)°, V = 1231.7(6)3, Z = 4, C14H10F2N2O, Mr = 260.24, Dc = 1.403 g/cm3, μ(MoKα) = 0.111 mm-1, F(000) = 536, the final R = 0.0453 and wR = 0.1085 for 1317 observed reflections (I > 2σ(I)) for Ⅱ. The antibacterial activities of both compounds against two bacteria were first studied and one compound showed considerable antibacterial activity against K. Pneumonia and S. aureus.     

Synthesis, Characterization, Spectroscopy and Study of Antimicrobial Properties of Two New Substituted Trichloroaluminate（Ⅲ） Complexes [AlCl3X]- （X = SCN-, CN-）

The synthesis and characterization of two new aluminate(Ⅲ) complexes with general formula K[AlCl3X] are reported. These compounds derived from aluminate trichloride and related salts. Potassium trichlorothiocyanoaluminate, PCTA, and potassium trichlorocyanatoalu-minate, PCCA, are two new ionic aluminate complexes. They can be easily synthesized in a nearly quantitative yield by using the direct reaction of AlCl3 and KX. The complexes were characterized by physico-chemical and spectroscopic methods. Theoretical calculations have been used for the extraction of structural and spectroscopic data of these new synthesized complexes. The antibacterial activities of such compounds were studied against the Staphylococcus aureus, Escherichia coli, Staphylococcus Epidermidis, Estreptococo B and Shigella.     

2,2＂-Bipyridine Adduct of Bis（O,O＇-di（2- phenylethyl）dithiophosphato）cadmium（ll）： Synthesis, Spectroscopic Characterization, Crystal Structure and Antibacterial Activity

A new 2,2＂-bipyridine adduct of bis（O,O＇-di（2-phenylethyl）dithiophosphato） cadmium（II）, [Cd{S2P（OCH2CH2Ph）2}2＂bipy] （1, bipy -- 2,2＂-bipyridine）, was synthesized and characterized by elemental analyses, IR, UV-vis, 1H NMR, fluorescence spectroscopy, thermo-gravimetric analysis, and X-ray single-crystal diffraction. The crystal of 1 crystallizes in triclinic, space group P1 with a = 10.4607（19）, b = 11.679（2）, c = 18.480（3） A, a = 98.900（2）, β = 103.321（2）, ）, = 91.779（2）, V= 2165.2（7） A3, Dc = 1.447 g/cm3, Z = 2, C42H4404N2P2S4Cd, Mr = 943.37, F（000） = 968,μ = 0.814 mm-1, the final R = 0.0536 and wR = 0.1206 for 6275 observed reflections with 1 〉 2a（/） and R = 0.0690 and wR = 0.1339 for all data. The result shows that the Cd（1） centre is five-coordinated by two N and three S atoms in a highly distorted square pyramidal configuration. The C-H＇＂S hydrogen bonding interactions and a set of weak intermolecular r-r stacking between adjacent aromatic rings stabilize the structure and make 1 assemble into a 1D zig-zag chain. In addition, the antibacterial activities of 1 against Escherichia coli, Bacillus subtilis and Staphylococcus bacteria were also screened by disc diffusion method.     

2,6,6-三甲基-双环[3,1,1]庚基-3-(4-芳基-2-噻唑)腙类化合物的合成及其抑菌和抗肿瘤活性研究

以α-蒎烯为起始原料,经加成、氧化、缩合制得中间体,继而与α-溴代芳基乙酮在常温下反应合成12个新型2,6,6-三甲基-双环[3,1,1]庚基-3-(4-芳基-2-噻唑)腙类化合物,产率达52.4%~88.9%.其结构经1H NMR,13C NMR,IR,LC/MS和元素分析进行了确证.初步生物活性测试结果表明:部分目标化合物具有较好的抑菌活性和一定的抗肿瘤活性.     

石墨烯/锌铁氧体复合物的制备及抗菌性能

用氧化还原法和化学共沉淀法分别制备了石墨烯(GE)和石墨烯/锌铁氧体(GE/ZnFe2O4)复合物,通过现代测试技术表征了样品的物相结构、组成和微观形貌.以大肠杆菌、金黄色葡萄球菌和白色念珠菌为测试菌种,分别对样品的抗菌性能进行了研究.结果表明,样品的抗菌活性受GE/ZnFe2O4复合物中GE和ZnFe2O4质量比(mG/Z)以及菌种的影响,其中mG/Z=0.4的复合物对三种菌均有较好的抗菌效果,其最小抑菌浓度分别为25、25和12.5μg/mL;复合物对白色念珠菌的抗菌效果最好,这与菌种的结构有关.此外,对样品的抗菌机理进行了详细研究.     

槲皮素-3-O-丙基衍生物的合成及生物活性研究

槲皮素是具有丰富生物活性的黄酮类化合物,药理活性显著。本文以槲皮素为先导物,选择性对C环3位羟基进行修饰,以廉价的芦丁为原料,经苄基保护、Williamson成醚反应,再经Pd/C催化加氢脱苄基得到28个未见文献报道的槲皮素-3-O-丙基衍生物,其结构经¹H NMR、¹³C NMR、ESI-MS进行确证。采用MTT法考察了所合成化合物对人食管鳞癌（EC109）、人胃癌（HGC27）、人乳腺癌（MCF-7）、小鼠黑色素瘤（B16-F10）的增殖抑制作用。结果显示,通过化学方法对槲皮素结构进行修饰后,其体外抗肿瘤活性增强。其中,化合物F3(IC₅₀=5.23±0.37μmol/L)、F5(IC₅₀=2.63±0.09μmol/L)对小鼠黑色素瘤（B16-F10）抑制作用比5-氟尿嘧啶(IC₅₀=14.38±0.27μmol/L)好,值得进一步研究。     

Conifers Phytochemicals: A Valuable Forest with Therapeutic Potential

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.