Evaluation of the Antibacterial and Antifungal Capacity of Nanoemulsions Loaded with Synthetic Chalcone Derivatives Di-Benzyl Cinnamaldehyde and Benzyl 4-Aminochalcone

With the increase in antimicrobial resistance,it has become necessary to explore alternative approaches for combating and preventing diseases.DB-cinnamaldehyde(CNM)and Benzyl4-amino(B4AM)are bioactive compounds derived from chalcones but with restricted solubility in aqueous media.Nanoemulsions can enhance the solubility of compounds and can be a promising alternative in the development of novel antimicrobials,with reduced side effects and prolonged release.The objective of this study was to evaluate the stability of oil-in-water nanoemulsions loaded with two distinct types of chalcones at two different dosages,to propose a stable formulation with antimicrobial properties.Results showed that nanoemulsions presented high encapsulation efficiency,low polydispersity index(PDI)and particle size below 200 nm,indicating that emulsification was a suitable method for nanoemulsion preparation.Nanoemulsions with higher dosages exhibited significant antimicrobial effects when compared to free chalcones and positive controls.Notably,B4AM nanoemulsions at higher dosages showed expressive activity against Salmonella minnesota,with a 420%greater inhibitory response compared to the free form and showing equivalence to the positive control.CNM nanoemulsions showed excellent inhibitory activity at the highest dosage,equivalent to the positive control against S.minnesota and Staphylococcus aureus.The greater number of conjugated bonds in CNM increased the antimicrobial activity in comparison with B4AM,and the formation of nanometric domains enhanced the bioavailability,being a promising alternative for antimicrobial applications.

含冠醚环的查尔酮(Chalcones)的合成

查尔酮是合成黄酮类化合物的中间体,有些查尔酮有生理活性,例如:含卤素、羟基或杂环的查尔酮有抗菌活性。为了合成含冠醚环的黄酮类化合物,我们用4′-甲酰基苯并-15-冠-5(1)与邻羟基苯乙酮或其取代物(2)缩合,合成了一系列含冠醚环的查尔酮(3):

A novel impedance immunosensor based on O-phenylenediamine modified gold electrode to analyze abscisic acid

An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL...

Two new chalcones from Fordia cauliflora

Two new chalcones,β,2′,4′,5′-tetramethoxychalcone 1,andβ,2′,5′-trimethoxyfurano[4″,5″：3′,4′]-chalcone 2 were obtainedfrom an ethyl acetate-soluble fraction of ethanol extract of the stem of Fordia cauliflora.Their chemical structures were determinedby analysis of spectroscopic evidences.

A Solid Phase Synthesis of Chalcones by Claisen-Schmidt Condensations

In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroquine-resistant strains of Plasmodium falciparum, a methodology for the solid phase synthesis of chalcone (1, 3-diphenyl-2-propen-1-one) analogues in reasonably high yields has been developed.

(E)-2-Benzylidenecycloalkanones XII.*Kinetic Measurement of Bovine and Human Serum Albumine Interaction with Selected Chalcones and Their Cyclic Chalcone Analogues by UV Spectrophotometry

UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.

Polymerization of o-Phenylenediamine Catalyzed byHemeproteins Encapsulated in Reversed Micelle

Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe 3+/Fe 2+(E m7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.

Studies on the Reaction Between α－Acetylthioformanilide and o-Phenylenediamine

,3-Disubstituted quinoxalines were synthesized from α-acetylthioformanilide and ophenylenediamine. Further studies sliowed that there existed competitive re- actions. One was a condensation reaction which produced substituted quinoxaline and the other was a substitution reaction which produced substituted quinoxaline-2- thione.

THE REACTION OF ETHYL AROYLACETATES AND o-PHENYLENEDIAMINE

Instead of 2-(aroylmethylene)benzimidazolines 3 or 2-(aroyl-methyl)benzimidazoles 4, 4-aryl-2, 3-dihydro-1H-1, 5-benzodiazepin-2-ones 5 were obtained exclusively from the reaction of o-phenylenediamine (1) and ethyl aroylacetates 2 in the presence of a catalytic amount of potassium hydroxide.

Antioxidant and Cytotoxicity Potential of Six Synthesized Chalcones

Background: Chalcones are open-chain flavonoids which display a large number of pharmacological activities such as cytotoxic, anti-inflammatory including antioxidant. The objective of this study was to assess antioxidant and cytotoxic activity of six synthesized chalcones. Methodology: For the current experiments, 1,3-diphenylpropenone (compound R) was used as molecular model to synthetize six compounds, namely three benzyl-benzimidazolyl-chalcones (U1, U2, WAC1) and three imidazopyridinyl-chalcones (V1, V2, V3). All the compounds were evaluated for their ability to scavenge the stable free ABTS.+ radical cation, according to the method develop by Choong et al. In addition, the cytotoxicity test described by Price et al., was performed using healthy human cell line, then in human malignant cell lines (HEP-2, A549). Results: All synthesized chalcones reduced the ABTS.+ radical cation. Indeed, benzyl benzimidazolyl compounds WAC1, U1, U2, by developing respectively 39.61%, 66.09%, and 84.20% percentages of reduction, showed an antioxidant effect 6, 11 and 14 times greater than the compound R (6.14%). As a result, imidazopyridinyl-chalcones compounds, namely V1, V2 and V3 reduced the ABTS.+ radical cation at 91.62%, 99.84% and 97.45% respectively, being 15 and 16 times more active than the compound R. About cytotoxicity, V2 inhibited not significantly HEP-2 malignant cells growth at 48.64%, compared to the standard product, i.e. doxorubicin that inhibited the growth of the same cells at 42.37%. WAC1 inhibited significantly the growth of A549 malignant cells at 89.53%, more than doxorubicin which percentage of growth inhibition was 71.58%. Conclusion: The presence of the α, β-unsaturated carbonyl system (or 1,3-diphenylpropenone) along with a benzimidazole or imidazopyridine heterocyclic ring is likely to contribute to both cytotoxic and antioxidant activities of these compounds.

Investigation of Interaction of Some Chalcones and Cyclic Chalcone Analogues with Outer Mitochondrial Membrane by UV-VIS and Fluorescence Spectroscopy

Interaction of the synthetic chalcones (1b,1c) and their cyclic analogues (2b,2c) with bovine (BSA) and human serum albumin (HSA) as well as with rat liver mitochondria (RLM) was studied by fluorescence spectroscopy. The maxima of emission fluorescence spectra were changed only in the case of 2b and 2c during interaction with BSA, HSA as well as mitochondrial outer membrane showing a slight hypsochromic shift and decrease of fluorescence. Interaction of the methoxy-(1b,2b) and the dimethylamino-substituted (1c,2c) compounds with outer mitochondrial membrane were studied by fluorescence polarization. Fluorescence polarization of 1b in the presence of the two proteins and mitochondria was found to be unchanged. Under similar conditions (2b,1c,2c) showed continuously increasing fluorescence polarization signal during the 30 minute period of investigations. Since fluorescence polarization supposes that as a result of binding these substances to proteins and lipids. Compound 2c displayed a continuous increase of fluorescence polarization signal in the presence of proteins (BSA, HSA), yeast cytoplasm (YC) and mitochondria (YM and RLM). This compound displayed a significant cytotoxic effect. This pattern of interaction with proteins might be one of the contributing vectors of the observed cytotoxicity against several human carcinoma cell lines.

Protonation Sites in Benzimidazolyl-Chalcones Molecules: An ab Initio and DFT Investigation

In this work, we have focused our investigations on the protonation sites predilection in the benzimidazolyl- chalcones (BZC) derivatives. Particularly, we are interested in the study of geometrical and energetical parameters. BZC are well known for their particularly nematicidal activity. Ten (10) BZC derivatives coded BZC-1 to BZC-10, with various larvicidal concentrations, have been selected for this work. They all are different one from another by the phenyl ring which is substituted by electron modulators such as alkyl, hydroxyl, alkoxy, aminoalkyl, halogen and nitro or replaced by the furan. Quantum chemical methods, namely HF/6-311 + G(d,p) and MPW1PW91/6- 311 + G(d,p) theory levels have been used to determine the geometrical and energetical parameters by the protonation on each heteroatom of the BZC derivative. An accuracy results with relatively less time consuming has been obtained using Hartree-Fock (HF) and Density Functional Theory methods (DFT/MPW1PW91). The calculations results allow identifying the sp2 nitrogen as the preferential site of protonation in BZC derivative compounds.

新型查尔酮衍生物抗乳腺癌活性的3D-QSAR模型构建及分子设计

为了获得较高抗乳腺癌活性的新型化合物,对18个新型查尔酮衍生物抗乳腺癌活性(pIC_(50))进行了三维定量构效关系(3D-QSAR)研究。其中14个化合物作为训练集用于构建3D-QSAR模型,其余化合物(含模板分子)作为测试集对所建模型进行验证。所建3D-QSAR模型的交叉验证系数R^(2)_(CV)为0.569,非交叉验证系数R^(2)为0.974,说明所建模型具有良好的稳定性和预测能力。该模型中立体场、静电场对pIC_(50)的贡献分别为58.8%和41.2%,表明影响该类化合物抗肿瘤活性的主要因素是取代基的疏水性、空间位阻和电荷分布。通过对模型的分析,设计了5个具有较高pIC_(50)的新化合物,有待通过后续医学实验加以验证。

大白菜CHS基因鉴定及其在高氮水平下转录表达分析

为了探究高氮水平引起大白菜叶柄黑点症加剧的机制,通过对抗、感叶柄黑点症大白菜品系进行正常氮和高氮水平处理,处理前和处理后不同时间对叶柄取样并进行转录组测序,然后再对大白菜查尔酮合酶(chalcone synthetase,CHS)基因进行鉴定并分析不同的大白菜CHS基因在正常氮水平和高氮水平、抗性品系和感性品系之间的差异表达,结果表明,共鉴定到7个大白菜CHS基因,其中有3个(BrCHS1、BrCHS3及BrCHS4)在高氮水平下表达量比正常氮水平下高,且在高氮水平下感性品系表达量高于抗性品系。因此推测这3个大白菜CHS基因可能与大白菜叶柄黑点症的形成有关。研究结果为揭示大白菜叶柄黑点症发生机制奠定了基础。

非甾体抗炎药修饰查尔酮衍生物的制备和表征

长期服用非甾体抗炎药会给患者带来严重的副作用,如胃肠道出血、心血管疾病等。受查尔酮生物活性多样性的启发,本文以非甾体抗炎药(阿司匹林、布洛芬、萘普生、甲灭酸、氟灭酸、依托度酸、吲哚美辛)和查尔酮为原料,EDCI为缩合剂,DMAP为催化剂,经酯化反应得到7种查尔酮衍生物,产物的收率为67%~86%。

甘草查尔酮A与三种抗生素联用对产气荚膜梭菌感染小鼠的治疗作用

本研究旨在研究中药单体与抗生素联用对产气荚膜梭菌(Clostridium perfringens,CP)感染小鼠的影响。本试验以甘草查尔酮A(licorice chalcone A,LCA)为代表药物,探究LCA与抗生素联用的体外和体内治疗效果,通过联合药敏试验确定与中药单体LCA有协同作用的抗生素,测定了产气荚膜梭菌在不同浓度药物作用下的杀菌曲线、溶血试验、滑动试验以及对小鼠的气性坏疽治疗效果,比较不同种抗生素在不同浓度下与LCA联用的治疗作用。结果表明,克林霉素(clindamycin,CLDM)、四环素(tetracycline,TCN)、替米考星(tilmicosin,TMS)三种抗生素与LCA有协同作用。根据杀菌曲线结果显示,8μg·mL^(-1)LCA和16μg·mL^(-1)TMS几乎可以完全杀灭产气荚膜梭菌;2μg·mL^(-1)LCA与2μg·mL^(-1)TMS联合使用可显著降低细菌的溶血性,溶血几乎完全被抑制(溶血定量为9.08%)。值得注意的是,LCA对细菌的迁移力有一定的促进作用,能够提高菌毛介导的运动性,与TMS联用后其促进作用显著提升。动物体内试验结果表明,CLDM单独使用时对产气荚膜梭菌具有较好的抑制作用,治疗效果显著;TCN和TMS分别与LCA联合使用时表现出协同作用(FIC指数为0.375),同时治疗时也表现出较好的增效效果。因此,在治疗产气荚膜梭菌感染时,TMS与LCA联合作用,可以降低药物使用量并提高治疗效果。

多星韭AwCHI 1的克隆与分析及真核表达载体的构建

查尔酮异构酶(Chalcone isomerase,CHI)是类黄酮物质合成途径中的关键酶,能催化柚皮素查尔酮生成柚皮素,进而转化生成各种类型的黄酮类化合物。根据多星韭(Allium wullichii)转录组测序结果,运用PCR技术克隆获取多星韭查尔酮异构酶的编码基因(AwCHI 1),对基因序列进行分析,同时与真核表达载体pBI121进行连接,将其转入农杆菌GV3101感受态细胞中,完成农杆菌的转化。研究结果不仅为该基因的功能解析研究奠定了基础,也为多星韭类黄酮代谢途径的研究提供了重要基因资源。

Licoagrochalcone A的首次全合成

以对羟基苯甲醛和2,4-二羟基苯乙酮为原料,经C-异戊烯基化、选择性保护酚羟基、羟醛缩合和去保护基4步反应,首次完成了天然产物Licoagrochalcone A的全合成(总收率26.0%),其结构经1H NMR,IR和MS确证。

多花黄精查尔酮合酶PcCHS的原核表达、亚细胞定位及表达分析

【目的】探究查尔酮合酶(chalcone synthase,PcCHS)基因在多花黄精类黄酮合成中的作用,为后续解析PcCHS功能以及多花黄精新品种选育提供可靠的理论依据。【方法】以多花黄精为cDNA模板,克隆多花黄精PcCHS基因的编码序列,对该基因进行生物信息学分析。通过构建PcCHS的原核表达载体,纯化目的重组蛋白,验证该酶的体外表达活性。利用瞬时超表达体系探究该基因过表达后总黄酮的含量变化。利用Gateway技术构建亚细胞定位载体35S::PcCHS-GFP,通过本氏烟草表达系统确定目的蛋白亚细胞定位情况。【结果】PcCHS基因的开放阅读框为1 251 bp,理论分子量为44.63 kD,等电点为5.89,属于亲水蛋白,与石刁柏(Asparagus officinalis)CHS亲缘关系较近。原核表达实验表明,pET28a-PcCHS经IPTG(异丙基-β-D-硫代半乳糖苷)诱导表达可溶性重组蛋白,Western-blot显示大小约为45 kD,与预期大小一致,且纯化的目的蛋白具有一定的酶活性,能催化对香豆酰辅酶A和丙二酰辅酶A转化为柚皮素查尔酮。此外,PcCHS瞬时超表达中,PcCHS组的表达量显著高于空载K组,总黄酮含量也显著高于空载K组,最高可达1.83倍。亚细胞定位结果显示,该基因在细胞膜和细胞核中发挥作用。【结论】PcCHS基因原核表达的酶具有体外酶活性,其亚细胞定位于细胞膜和细胞核,且瞬时超表达能够显著提高多花黄精叶片总黄酮含量。