In vitro antioxidant,antifungal and antibacterial activities of five international Calibrachoa cultivars

The total phenolic, flavonoid and tannin contents in leaf extracts of Calibrachoa x hybrida (C.h.) (Solanaceae) international cultivars, as well as their overall antioxidant activities using DPPH and linoleic acid assays, were investigated. Furthermore, the antifungal and the antibacterial activities were examined against a wide spectrum of micro-organisms. DPPH and linoleic acid assays ranged from 62.1 to 80.1% and of 74.1–93.4%, respectively. C.h. Superbells® Trailing Rose (CHST), C.h. Superbells® Frost Fire, C.h. Superbells® Strawberry Punch, C.h. Superbells® Dreamsicle and C.h. Superbells® Plum (CHSP) varied in their antifungal and the antibacterial activities against a wide spectrum of micro-organisms. CHSP exhibited the highest antioxidant, antifungal and antibacterial activities followed by CHST. These activities might be attributed to the presence of phenolic, flavonoid and tannin compounds, indicating that these cultivars might be potential sources of therapeutic substances.     

3-Thiolated 2-azetidinones: synthesis and in vitro antibacterial and antifungal activities

A series of 3-thiolated β-lactams were synthesized by [2+2] ketene-imine cycloaddition reaction from S-substituted mercaptoacetic acids and Schiff bases. Then, some of the 3-methylthio β-lactams were converted to 3-(methylsulfinyl) β-lactams and 3-(methylsulfonyl) β-lactams using m-CPBA under different reaction conditions. All the compounds were characterized by spectral data and elemental analyses and were evaluated for their in vitro antibacterial and antifungal activities against pathogenic strains including Staphylococcus aureus (Methicillin resistant strain). The preliminary screening results indicated that some of these compounds demonstrated moderate to very good antibacterial and antifungal activities.     

Synthesis of CuS and ZnO/Zn(OH)2 nanoparticles and their evaluation for in vitro antibacterial and antifungal activities

In this study, the copper sulfide nanoparticles (CuS‐NPs) and the zinc oxide/zinc hydroxide nanoparticles ((ZnO/Zn(OH)₂‐NPs) were synthesized by a simple and low‐cost method, and the synthesized nanoparticles were characterized and identified by UV–Vis, field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The antimicrobial activity of the CuS‐NPs and the ZnO/Zn(OH)₂‐NPs were examined by broth dilution to determine the minimal inhibitory concentration (MIC) of antibacterial agent required to inhibit the growth of a pathogen and the minimum bactericidal concentration (MBC) required to kill a particular bacterium. Agar disc diffusion method was used to determine the zone of inhibition. The nanoparticles demonstrated potent antibacterial activity against Klebsiella pneumonia (ATCC 1827), Acinetobacter baumannii (ATCC 150504), Escherichia coli (ATCC 33218) and Staphylococcus aureus (ATCC 25293). Antifungal activity against Aspergillus oryzae (PTCC 5164) was also obtained. The data obtained from antimicrobial activities by broth dilution and agar disc diffusion methods exhibited the CuS‐NPs were more effective than the ZnO/Zn(OH)₂‐NPs. A good correlation was observed between the data obtained by both methods.     

2-甲酰基-3-乙酰基-4-甲基-5-苄氧羰基吡咯的合成

甲酰基乙酰基甲基苄氧羰基吡咯;二甲基乙酰基苄氧羰基吡咯;加成环化;选择性氧化     

Synthesis of 3-substituted-4-methyl-5-acetyl-4-thiazoline-2-thione

The reaction of various potassium salts [RNHC(=S)SK, R = N(CH₃)₂, morpholino, piperidino, and hexahydro-1-(1H)-azepinyl] with 3-chloro-2,4-pentanedione in ethanol at 25–30° afforded the 1-acetylacetonyl substitutedaminodithiocarbamates 1–4 [RNHC(=S)SCH(COCH₃)₂]. Under refluxing conditions, the same reactants gave the heterocyclic compounds 5–8. Possible mechanism and supporting ir, nmr and mass spectral data are discussed.     

One-pot synthesis of new hydantoin (thiohydantoin) derivatives and evaluation of their antibacterial and antioxidant activities

One-pot four-component reactions of phenacyl bromides, parabanic or thioparabanic acids, thiophenols, and triphenylphosphine in the presence of triethylamine afforded new derivatives of hydantoin or thiohydantoin in good to high yields (65%-90%). Their antibacterial activities were evaluated against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Among the synthesized compounds, the obtained products from 2-hydroxythiophenol exhibited higher antibacterial activity than those obtained from 2-aminothiophenol. Compound 9l including N,N′^′-diphenyl thiohydantoin moiety showed the highest antibacterial activity (26.0 ± 01.4) against B subtilis, in comparison with other synthesized samples. The antioxidant activities of the synthesized hydantoins and thiohydantoins were investigated by DPPH radical-scavenging based on Blois method. The results showed that all the compounds have high DPPH inhibition potency (77.4%-83.9%) that it could be due to existence of heteroatoms with lone pair electrons and exchangeable protons on their NH₂ and OH groups.     

Diversity oriented design of various benzophenone derivatives and their in vitro antifungal and antibacterial activities

A series of new substituted benzophenone derivatives was designed, synthesized and screened for their antifungal and antibacterial activities. The bioassays indicated that most of the synthesized compounds showed some antifungal activity against the tested phytopathogenic fungi, but lower antibacterial activities towards the five vibrios isolated from marine sources. The preliminary structure activity relationship (SAR) of the compounds was also discussed.     

A new synthesis of N-alkyl 3-acetyl-4-methoxycarbonylmethyl-2-methyl-1,4-dihydropyridines utilizing sec-aminodienyl esters with acetylacetone

The reactions of sec-aminodienyl esters 3 with acetylacetone (4) afforded N-alkyl 3-acetyl-4-methoxycarbonylmethyl-2-methyl-1,4-dihydropyridines 5 and enamines 6, providing a new azaelectrocyclization reaction.     

Synthesis,characterization, antioxidant,and antibacterial activities of new 2,3-dimethoxy and 3-acetoxy-2-methyl benzamides

Research on Chemical Intermediates - We performed a series of novel benzamide compounds which were synthesized starting from 2,3-dimethoxybenzoic acid or 3-acetoxy-2-methylbenzoic acid and amine...     

Synthesis of 2-acetyl-3-methyl-4H-1,4-benzothiazine and its derivatives

Summary 2-Aminothiophenol (1) reacts with 3-chloro-2,4-pentanedione (2) in the presence of pyridine to form 2-acetyl-3-methyl-4H-1,4-benzothiazine (3) in high yields. Reaction of3 with hydrazine gives 4-(2-aminophenylthio)-3,5-dimethylpyrazole (5). Condensation of3 with 4-nitrobenzaldehyde yields the corresponding Schiff base7. Hydroxylamine with benzothiazine3 affords 3,9a-dimethyl-3a, 9a-dihydro-9H-isoxazolo[4,5-b][1,4]benzothiazine (8).

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Synthese von 2-Acetyl-3-methyl-4H-1, 4-benzothiazin und seinen Derivaten

Zusammenfassung 2-Aminothiophenol (1) reagiert mit 3-Chlor-2,4-pentandion (2) in Anwesenheit von Pyridin unter Bildung von 2-Acetyl-3-methyl-4H-1,4-benzothiazin (3) in sehr hoher Ausbeute. Benzothiazin3 kondensiert mit Hydrazin zu 4-(2-Aminophenylthio)-3,5-dimethylpyrazol (5), dessen Aminogruppe reagiert mit 4-Nitrobenzaldehyd zu einer Schiffschen Base (7), die spektroskopisch charakterisiert wurde. Benzothiazin3 mit Hydroxylamin ergibt 3,9a-Dimethyl-3a,9a-dihydro-9H-isoxazolo[4,5-b][1,4]benzothiazin (8). Die Stereochemie der letztgenannten Verbindung wurde ermittelt.

     

Acid — Base properties of 3,4-dimethyl-2-thiazolone, 4-methyl-2-thiazolone,and 5-acetyl-4-methyl-2-thiazolone

In contrast to 2-methoxy-4-methylthiazole and 2,4-dimethylthiazole, the protonation of 3,4-dimethyl-2-thiazolone does not proceed in media with acidities up to H₀=–3.99. The acidity of N-H increases by 2.4 orders of magnitude on passing from 4-methyl-2-thiazolone to its 5-acetyl derivative. The data obtained from a study of the acid-base properties in conjunction with the results of calculations of the 3,4-dimethyl-2-thiazolone and thiazole molecules by the MO method make it possible to conclude that there is a charge in the 5 position of 2-thiazolones and that this is the reason for the facile acylation of these compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1622–1625, December, 1972.     

Synthesis and characterization of new thiazolidinones containing coumarin moieties and their antibacterial and antioxidant activities

New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, N-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and N-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide) were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP). The new compounds were screened for antibacterial activity. Most of them are more active against E. coli S. aureus and B. subtilis than standard references.     

Synthesis, antibacterial, antifungal and antiviral activity evaluation of some new bis-Schiff bases of isatin and their derivatives

Twelve new bis-Schiff bases of isatin, benzylisatin and 5-fluoroisatin 3a-3l were prepared by condensation of isatin, benzylisatin and 5-fluoroisatin with primary aromatic amines. The chemical structures of the products were confirmed by 1H- and 13CNMR, IR and mass spectral data. The compounds were screened for antiviral activity against a panel of DNA and RNA viruses. Minimum cytotoxic and minimum virus-inhibitory concentrations of these compounds were determined. Compounds 3c and 3i were the most cytotoxic in HEL cells. These newly synthesized bis-Schiff bases were also tested for their antibacterial and antifungal activities. They did not display activity against S. cerevisiae (ATCC 28383) or C. albicans (CIP 1180-79).     

Synthesis of 6,8-dichloroquinolones utilizing new method and evaluation of their antibacterial activities

Several 6,8-dichloroquinolone analogues were synthesized from the key intermediate compound of 2,3,4,5-tetrachlorobenzene carbonyl chloride,which was obtained from the starting material of tetrachlorophthalic anhydride.Their in vitro antibacterial activities were evaluated.As a result of this study,compounds 21c and 21d were twofold more potent than ciprofloxacin (CPFX) and norfloxacin (NFLX) against Staphylococcus aureus-9,and with the same potent as CPFX and NFLX while against Escherichia coli-2,but were less potent than references in against Pseudomonas aeruginosa-17.     

Synthesis of bipyrazoles and pyrazoloisoxazoles from 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one

Phenylhydrazine or hydrazine react with 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one ( 1 ) to give 4-acetoacetyl-3-methylpyrazolin-5-ones 4 . The synthesis of bipyrazoles and pyrazoloisoxazoles from 4 are reported.     

A new indole alkaloid,antioxidant and antibacterial activities of crude extracts from Saccocalyx satureioides

Abstract

The new acylated indole alkaloid glucoside indole-3-carboxylic acid-(6'-O-caffeoyl)-β-D-glucoside 1 has been isolated from the ethyl acetate (EtOAC) extract of Saccocalyx satureioides Coss. & Dur. (Lamiaceae) together with eight known secondary metabolites 2-9. Two indoles 2 and 3, five methylated flavone aglycones 4-8 and one monoterpene glucoside 9 were reported for the first time in the genus Saccocalyx. The structural elucidation of these compounds was accomplished by spectroscopic methods including 1?D (¹H and ¹³C) and 2?D (COSY, HSQC and HMBC) NMR techniques, and mass spectrometry, and by comparison with literature data. Light petroleum, EtOAc, chloroform and n-butanol (n-BuOH) extracts of S. Satureioides were screened for their antioxidant activity using DPPH radical scavenging and β-carotene bleaching methods. The antibacterial activity of these extracts indicates that n-BuOH and EtOAc extracts possess the strongest activity.