Antimicrobial activity of organotin(IV) compounds: a review

A comprehensive review on antimicrobial activity of organotin(IV) compounds is presented. Copyright © 2008 John Wiley & Sons, Ltd.     

Inula viscosa (L.) Aiton leaves and flower buds: Effect of extraction solvent/technique on their antioxidant ability,antimicrobial properties and phenolic profile

Abstract

This study was designed to establish the most effective solvent/technique for extracting antioxidant phytoconstituents from leaves and flower buds of Inula viscosa (L.) Aiton (Asteraceae) grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. The antioxidant potential was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. I. viscosa leaf and flower bud extracts displayed the strongest effect in the DPPH test, being the Soxhlet ethanol the most active ones (IC₅₀ = 54.24?±?0.21?μg/mL and 39.77?±?0.23?μg/mL); thus, they were selected for further investigations. The antimicrobial efficacy of the Soxhlet ethanol extracts against ATCC and food isolates strains was assayed; the leaf extract showed the best activity, and Candida albicans was the most sensitive strain (MIC = 125?µg/mL). The extracts resulted non-toxic against Artemia salina. Among the phenolics characterised by HPLC-PDA-ESI-MS, hispidulin hexoside, patuletin and spinacetin were identified for the first time.     

Biological characteristics of Edgeworthia tomentosa (Thunb.) Nakai flowers and antimicrobial properties of their essential oils

Edgeworthia tomentosa (Thunb.) Nakai belongs to Thymelaeaceae family, its alabastrum is used as the traditional Chinese medicine ‘Buddleja Officinalis Maxim’. The present study was to elucidate the ultrastructure characteristics of the flower, the phytochemical composition of the aroma essential oils (EOs) and the relevant antimicrobial properties. There were exclusive characters of calyx, ovule, anther and pollen grain of the flowers under scanning electron microscopy. A total of 40 phytochemical components representing 98% of the EOs were successfully identified: monoterpenes and sesquiterpenes were the dominant terpenoids according to Kovats retention index and MS database. EOs exhibited a broad spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria, the best bacteriostatic effect was against Diplococcus pneumonia with MIC and MBC values ranging between 7.8 and 62.5 and 26.0–71.0 μg/mL, respectively. These results demonstrate that the surface microscopic morphological characteristics of Edgeworthia chrysantha Lindl. flowers, are full-scale chemical composition and antimicrobial properties of the EOs.     

新型2-(2'-取代亚肼基)-1,3-二硫杂环戊烷衍生物的合成和菌活性研究

通过结构改造并结合活性基团的拼接合成了11个未见文献报道的新型2-(2'-取代亚肼基)-1,3-二硫杂环戊烷类化合物,所有的目标物的结构都经HNMR,MS,IR和元素分析证实,选择了其中5个化合物对7种细菌进行了抑菌活性1测试,并与市售农药20%三环唑、70%威尔达甲托的抑菌活性进行对比,发现它们比市售农药有更为广泛的杀菌谱,对照农药只对金黄色葡萄球菌有良好的抑菌作用而这些化合物则对所选择的七个菌种均有良好的抑菌作用.其中化合物2-(对氟苯氧乙酰亚肼基)-1,3-二硫杂环戊烷(4c)的杀菌谱很广,它对金色葡萄球菌、大肠杆菌、白色念珠菌的抑杀活性都很好.     

Chemical constituents from the flowering buds of Bauhinia tomentosa Linn (FBBT)

Isolation and characterisation of compounds, 1-(2′-hydroxy-4′-methoxyphenyl)-3-(4″-methoxyphenyl)-2-hydroxypropane-1,3-dione (1), 5-hydroxyflavone (2), 3,5,7,3′,4′-pentahydroxyflavone (3), 3,5,7,2′,4′-pentahydroxyflavone (4) and 5,7,3′,4′-tetrahydroxyflavone-3-O-rhamnoside (5) are reported from the air dried flowering buds of Bauhinia tomentosa Linn. Their structures are determined on the basis of extensive chemical and spectral evidences. Compound (1) is reported for the first time from the plant source. While compounds (2) and (4) are reported for the first time from this genus, compound (2) is reported for the second time from the natural source.     

Thallium(I) Tropolonates: Synthesis,Structure, Spectral Characteristics,and Antimicrobial Activity Compared to Lead(II) and Bismuth(III) Analogues

Synthesis, single-crystal X-ray determination diffraction and FT-IR, NMR (¹H, ¹³C, ¹⁹F and ²⁰⁵Tl), UV–vis, and luminescence spectra characteristics were described for series of thallium(I) compounds: thallium(I) triflate (Tl(OTf)), 1:1 co-crystals of thallium(I) triflate and tropolone (Htrop), Tl(OTf)·Htrop, as well as simple thallium(I) chelates: Tl(trop) (1), Tl(5-metrop) (2), Tl(hino) (3), with Htrop, 5-methyltropolone (5-meHtrop), 4-isopropyltropolone (hinokitiol, Hhino), respectively, and additionally more complex {Tl@[Tl(hino)]₆}(OTf) (4) compound. Comparison of their antimicrobial activity with selected lead(II) and bismuth(III) analogs and free ligands showed that only bismuth(III) complexes demonstrated significant antimicrobial activity, from two- to fivefold larger than the free ligands.     

Antimicrobial and Anticancer Application of Silver(I) Dipeptide Complexes

Three silver(I) dipeptide complexes [Ag(GlyGly)]_n(NO₃)_n (AgGlyGly), [Ag₂(GlyAla)(NO₃)₂]_n (AgGlyAla) and [Ag₂(HGlyAsp)(NO₃)]_n (AgGlyAsp) were prepared, investigated and characterized by vibrational spectroscopy (mid-IR), elemental and thermogravimetric analysis and mass spectrometry. For AgGlyGly, X-ray crystallography was also performed. Their stability in biological testing media was verified by time-dependent NMR measurements. Their in vitro antimicrobial activity was evaluated against selected pathogenic microorganisms. Moreover, the influence of silver(I) dipeptide complexes on microbial film formation was described. Further, the cytotoxicity of the complexes against selected cancer cells (BLM, MDA-MB-231, HeLa, HCT116, MCF-7 and Jurkat) and fibroblasts (BJ-5ta) using a colorimetric MTS assay was tested, and the selectivity index (SI) was identified. The mechanism of action of Ag(I) dipeptide complexes was elucidated and discussed by the study in terms of their binding affinity toward the CT DNA, the ability to cleave the DNA and the ability to influence numbers of cells within each cell cycle phase. The new silver(I) dipeptide complexes are able to bind into DNA by noncovalent interaction, and the topoisomerase I inhibition study showed that the studied complexes inhibit its activity at a concentration of 15 μM.     

Synthesis,characterization and antimicrobial activity of pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with 2,6-diacetylpyridine bis(trimethylammoniumacetohydrazone)

Pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized and characterized by elemental analyses, IR and UV–vis spectra, molar conductivity, and magnetic susceptibility. Crystal structures of the Co(II) and Ni(II) complexes were also determined. Antimicrobial activities of the ligand and metal complexes were examined.     

含双咪唑配体的锌配位聚合物的晶体结构、荧光性质及抑菌性能研究

本文报道了一个基于双咪唑配体的锌配位聚合物[Zn(oxa)(bbi)]n(1)(oxa=草酸,bbi=1,1′-(1,4-丁二基)双咪唑),并对该化合物进行元素分析、红外和X-射线单晶衍射分析。结果表明标题化合物通过配位键和π-π堆积作用力形成了一个由(4,4)拓扑形状的二维网络组成的具有大孔洞的三维金属有机框架结构。除此之外,测定了配合物1的荧光发射光谱并对其微生物抑菌性能进行了初步研究。     

Synthesis,physico-chemical characterization and bioevaluation of Ni(II), Pd(II), and Pt(II) complexes with 1-(o-tolyl)biguanide: Antimicrobial and antitumor studies

New complexes of type [M(tbg)₂]Cl₂ [tbg = 1-(o-tolyl)biguanide; M = Ni(II), Pd(II), and Pt(II)] were synthesized and characterized to develop new biologically active compounds. The features of the complexes were assigned from microanalytical and thermal data. The NMR, FT-IR, and UV-Vis spectra were established by comparison with HtbgCl. All complexes exhibit a square-planar geometry resulting from the chelating behavior of tbg. The HtbgCl and [Ni(tbg)₂]Cl₂ complexes were fully characterized by single-crystal X-ray diffraction. The HtbgCl species crystallize in the monoclinic C2/c spatial group, while the Ni(II) complex adopts an orthorhombic Pna2₁ spatial group. The structure is stabilized by a complex hydrogen bonds network. The in vitro antimicrobial assays revealed improved antimicrobial activity for complexes in comparison with the ligand against both planktonic and biofilm embedded microbial cells. The most efficient compound, showing the largest spectrum of antimicrobial activity, including Gram-positive and Gram-negative bacteria, as well as fungal strains, in both planktonic and biofilm growth states was the Pd(II) complex, followed by the Pt(II) complex. The Pt(II) compound exhibited the most significant antiproliferative activity on the human cervical cancer SiHa cell line, inducing a cell cycle arrest in the G2/M phase.     

Monophenylantimony(III) Derivatives of Cyclic Dithiocarbamates; Synthesis,Spectroscopic Characterization,and Antimicrobial Study

Abstract

Some new monophenylantimony(III) compounds having the formulas have been synthesized by reaction of phenylantimony(III) dichloride with the sodium salt of cyclic dithiocarbamates in 1:1 and 1:2 molar ratios. These newly synthesized compounds have been characterized by elemental analyses, molecular weight measurements, and their plausible structures have been proposed on the basis of IR, NMR (¹H and ¹³C), and ESI-mass studies. Sodium salts of cyclic dithiocarbamates and their corresponding organoantimony(III) derivatives (1–8) have been screened for antimicrobial activity against E. coli, P. aeruginosa (Bacteria) and A. niger and A. flavus (Fungi).     

Synthesis,characterization, DFT calculations and antimicrobial activity of pentagonal-bipyramidal Zn(II) and Cd(II) complexes with 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone)

Isothiocyanate complexes of Zn(II) and Cd(II) with the condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized, characterized, and their antimicrobial activities were evaluated. The structures of the complexes were determined by elemental analysis, IR, and NMR spectroscopy. The crystal structure of the Zn(II) complex was also determined. Quantum-chemical calculations of the geometry and total energy of isomers of 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone) were performed in vacuum and methanol solution, with the aim to explain conformational behavior and E/Z isomerism of this compound. DFT calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N–Cd–N coordination of SCN^? is the most stable. Complexes of Zn(II) and Cd(II) exhibited low to moderate activity against the tested microbial strains.     

The Synthesis and Evaluation of Diethyl Benzylphosphonates as Potential Antimicrobial Agents

The impact of substituent at phenyl ring of diethyl benzylphosphonate derivatives on cytotoxic activity was studied. The organophosphonates were obtained based on developed palladium-catalyzed α, β-homodiarylation of vinyl esters protocol. The new synthetic pathway toward 1,2-bis(4-((diethoxyphosphoryl)methyl)phenyl)ethyl acetate was proposed which significantly improves the overall yield of the final product (from 1% to 38%). Several newly synthesized organophosphonates were tested as new potential antimicrobial drugs on model Escherichia coli bacterial strains (K12 and R2-R3). All tested compounds show the highest selectivity and activity against K12 and R2 strains. Preliminary cellular studies using MIC and MBC tests and digestion of Fpg after modification of bacterial DNA suggest that selected benzylphosphonate derivatives may have greater potential as antibacterial agents than typically used antibiotics such as ciprofloxacin, bleomycin and cloxacillin. These compounds are highly specific for pathogenic E. coli strains based on the model strains used and may be engaged in the future as new substitutes for commonly used antibiotics, which is especially important due to the increasing resistance of bacteria to various drugs and antibiotics.     

A new analog of pyrrolezanthine from the roots of Reynoutria ciliinervis (Nakai) Moldenke

In the present study, a new analogue of pyrrolezanthine (1) was isolated from the roots of Reynoutria ciliinervis (Nakai) Moldenke. Its structure was elucidated mainly by NMR, HR-ESI-MS and the single-crystal X-ray diffraction spectroscopic data. Meanwhile, the antimicrobial activity of compound 1 was measured, it exhibited potent antifungal activity against Sclerotinia sclerotiorum with MIC value of 31.2 μg/mL.     

Antimicrobial secondary metabolites of an endolichenic Aspergillus niger isolated from lichen thallus of Parmotrema ravum

Abstract

A new 6-benzyl-γ-pyrone (1), named aspergyllone was isolated from the culture filtrates of an endolichenic fungus Aspergillus niger Tiegh, obtained from lichen thallus Parmotrema ravum (Krog & Swinscow) Serus, collected in India. 1 was isolated for the first time from an endolichenic fungus together with six other known metabolites identified as aurasperones A (2) and D (3), asperpyrone A (4), fonsecinone A (5), carbonarone A (6) and pyrophen (7). The compounds were tested against a panel of human, plant, food borne and fish pathogens. Aspergyllone showed strong selective antifungal activity against Candida parapsilosis (Ashford) Langeron & Talice, with an IC₅₀ of 52?µg/mL. Aurasperone A and pyrophen showed moderate to strong antimicrobial activity inhibiting seven different test pathogens, being pyrophen active with IC₅₀ ranging from 35 to 97?µg/mL.

     

Synthesis,antimicrobial and antioxidant activity of bis sulfonamide/carbamate derivatives of bis-(4-aminophenyl) methane

A series of new bis sulfonamide/carbamate derivatives of bis-(4-aminophenyl)methane 3 ( a–d )/ 5 ( a–f ) were synthesized from bis-(4-aminophenyl)methane ( 1 ) using various pharmacologically active sulfonyl chlorides 2 ( a–d ) and carbonochloridates 4 ( a–f ) in high yields. The structures of all the newly synthesized compounds were characterized by the Infrared spectroscopy, NMR (¹H and ¹³C), mass, and elemental analyses. Further, all the synthesized compounds were tested for the antioxidant activity by using 2, 2-diphenyl-1-picrylhydrazyl, NO, and H₂O₂ scavenging methods and antimicrobial activity. Most of the compounds exhibited good antioxidant and antimicrobial activities.     

Dipyrrinato-Iridium(III) Complexes for Application in Photodynamic Therapy and Antimicrobial Photodynamic Inactivation

The generation of bio-targetable photosensitizers is of utmost importance to the emerging field of photodynamic therapy and antimicrobial (photo-)therapy. A synthetic strategy is presented in which chelating dipyrrin moieties are used to enhance the known photoactivity of iridium(III) metal complexes. Formed complexes can thus be functionalized in a facile manner with a range of targeting groups at their chemically active reaction sites. Dipyrrins with N- and O-substituents afforded (dipy)iridium(III) complexes via complexation with the respective Cp*-iridium(III) and ppy-iridium(III) precursors (dipy=dipyrrinato, Cp*=pentamethyl-η⁵-cyclopentadienyl, ppy=2-phenylpyridyl). Similarly, electron-deficient [Ir^III(dipy)(ppy)₂] complexes could be used for post-functionalization, forming alkenyl, alkynyl and glyco-appended iridium(III) complexes. The phototoxic activity of these complexes has been assessed in cellular and bacterial assays with and without light; the [Ir^III(Cl)(Cp*)(dipy)] complexes and the glyco-substituted iridium(III) complexes showing particular promise as photomedicine candidates. Representative crystal structures of the complexes are also presented.     

5-取代-2-羟甲基苯酚衍生物的合成及体外抗肿瘤活性研究

以2-羟基-4-甲基苯甲酸为原料, 经过丙酮叉保护、NBS溴代制得中间体7-(溴甲基)-2,2-二甲基-4H-苯并[d][1,3]二氧六环-4-酮（4）,再分别和两种杂环仲胺发生N-烷基化反应制得化合物5a-b,最后经过四氢铝锂还原得到目标化合物1a-b,其结构经1H NMR、13C NMR和ESI-MS进行表征。同时,考察了N-烷基化反应和还原反应的反应条件,确定了N-烷基化反应的最佳条件为：物料比为n（吡唑）: n（化合物4）= 1.2 : 1;K2CO3用量为n（K2CO3）: n（化合物4）= 2.0 : 1;50℃反应5 h。最佳还原反应条件为：LiAlH4用量为n（LiAlH4）: n（化合物5a）= 1.2 : 1,-75℃反应时间为1.0 h。此外,采用了MTT法测试了所合成的化合物1a-b对HepG2,HeLa,MCF-7,A5494四种肿瘤细胞以及正常宫颈上皮细胞HUCEC的体外抑制活性。结果表明,目标化合物1a-b对HeLa细胞展现出了明显的抑制作用,其IC50分别为18.4和10.6 μmol ? L-1,而对正常的HUCEC没有抑制活性。这些结果有望为进一步开发具有抗肿瘤活性的2-羟甲基苯酚衍生物提供参考。     

Towards the Antimicrobial Finishing of Poly(isoprene)

Summary: Anionically polymerised (poly)isoprene was functionalized with cysteamine applying thiol-ene click chemistry. Subsequent quaternisation of the primary amino groups gave polymers with antimicrobial activity against Listeria monocytogenes, Eschericchia coli, Pseudomonas fluorescens and Staphylococcus aureus as revealed from tests performed according to the Japanese Industrial Standard Z2801:2000. The novel polymers feature sufficient thermal stability for the compounding with commodity polymers such as poly(propylene) and might be used as a non leaching additive to finish commodity polymers with antimicrobial acitivity.