scholarly journals In VirtoAntioxidant Activities of New 4,5-Dihydro-1H,2,4-triazol-5-ones having Thiophene Ring with their Acidic Properties

2011 ◽  
Vol 8 (4) ◽  
pp. 1734-1746 ◽  
Author(s):  
H. Yuksek ◽  
F. Islamoglu ◽  
O. Gursoy Kol ◽  
S. Bahceci ◽  
M. Bekar ◽  
...  

Seven new 3-alkyl(aryl)-4-(2-thienymethylenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones(2)were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones(1)with thiophene-2-carbaldehyde. In addition,N-acetyl derivatives of compounds2d-2gwere also prepared. The structures of eleven new compounds synthesized were determined by elemental analysis as well as IR, NMR and UV spectral data. In addition, compounds2a-gand3a,3b,3d-fwere also screened for their antioxidant activities and2a-gwere potentiometrically titrated with tetrabutylammonium hydroxide (TBAH) in four nonaqueous solvents (isopropyl alcohol,t-butyl alcohol, acetonitrile andN,N-dimethyl formamide). Also half-neutralization potential values and the corresponding pKa values were determined in all cases.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
H. Yuksek ◽  
O. Akyildirim ◽  
O. Gursoy Kol

Nine new 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives were synthesized and characterized by elemental analyses and IR,1H-NMR,13C-NMR and UV spectral data. The synthesized compounds were analyzed for theirin vitropotential antioxidant activities in three different methods. Those antioxidant activities were compared to standard antioxidants such as BHA, BHT andα-tocopherol. Compounds4e,5aand5dshowed best activity for iron binding. In addition, the compounds4were titrated potentiometrically with tetrabutylammonium hydroxide (TBAH) in four non-aqueous solvents (isopropyl alcohol,tert-butyl alcohol, acetone andN,N-dimethyl formamide). Thus, the half-neutralization potential values and the correspondingpKavalues were determined in all cases.


2002 ◽  
Vol 67 (8) ◽  
pp. 1215-1222 ◽  
Author(s):  
Şule Bahçeci ◽  
Haydar Yüksek ◽  
Zafer Ocak ◽  
Ibrahim Azakli ◽  
Muzaffer Alkan ◽  
...  

The synthesis of 3-alkyl(aryl)-4-[4-(dimethylamino)benzylideneamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) with 4-(dimethylamino)benzaldehyde is described. The newly synthesized 3 type compounds were titrated potentiometrically with tetrabutylammonium hydroxide in three non-aqueous solvents, including acetonitrile, isopropyl alcohol and N,N-dimethylformamide. The half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, N-acetyl derivatives of 3 type compounds were also obtained. The new synthesized compounds in the study were fully characterized.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4271
Author(s):  
Asma Alshamari ◽  
Mahmoud Al-Qudah ◽  
Fedaa Hamadeh ◽  
Lo’ay Al-Momani ◽  
Sultan Abu-Orabi

A series of derivatives of trans-3-(2,4,6-trimethoxyphenyl)4,5-dihydroisoxazolo-4,5-bis[carbonyl-(4′phenyl)thiosemicarbazide (9) and of trans-3-(2,4,6-trimethoxyphenyl)-4,5-dihydro isoxazolo-4,5-bis(aroylcarbohydrazide) (10a–c) were synthesized from trans-3-(2,4,6-trimethoxyphenyl)-4,5-dihydro-4,5-bis(hydrazenocarbonyl)isoxazole (8). The structures of the compounds were elucidated by both elemental and spectral (IR, NMR, and MS) analysis. Compound 9 shows activity against some bacterial species. No antibacterial activities were observed for compounds 10a–c. The antioxidant activity of the new compounds has been screened. Compound 9 showed higher antioxidant activity using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2’-azino–bis(3-ethylbenzoline-6-sulfonic acid) diammonium salt methods.


1972 ◽  
Vol 55 (4) ◽  
pp. 762-767
Author(s):  
R D Stubblefield ◽  
O L Shotwell ◽  
G M Shannon

Abstract A survey of known anatoxin solvent systems for resolution of aflatoxins M1 and M2 on TLC plates revealed that the best system for determining aflatoxins B1, B2, G1, G2, M1, and M2 is isopropyl alcohol-acetone-chloroform (5 + 10 + 85). Substitution of various alcohols for isopropyl alcohol in this system demonstrated that maximum resolution of M1 and M2 was achieved with n-amyl alcohol-acetone-chloroform (10 + 10 + 80); however, B1, B2, G1, and G2 migrated with the solvent front. When alcohol-chloroform (5 + 95) mixtures were investigated, n-propyl, n-butyl, and tert-butyl alcohol + chloroform resolved M1 and M2 best but did not separate B1, B2, G1, or G2. Molar absorptivities of both M1 and M2 were determined in methanol, chloroform, acetonitrile, and acetonitrile-benzene (2 + 98). Relative fluorescent intensities of aflatoxins B1, M1, and M2 were compared on both developed and undeveloped TLC plates. Fluorescent intensities of B1 and M1 on silica gel were nearly equal, and the intensity of M2 was 1.4–1.5 times that of the other 2 aflatoxins. Water adducts of anatoxin M1 and parasiticol were prepared. The diacetate adducts of parasiticol were formed by treatment with acetic anhydride and concentrated HC1. Monoacetyl derivatives of M1, M2, and parasiticol were obtained by treatment with pyridine and acetic anhydride. Good resolution of the water-addition derivatives of B1, G1, parasiticol, and Mi on TLC plates was achieved with isopropyl alcoholacetone-chloroform (5 + 10 + 85).


Author(s):  
Asma Alshamari ◽  
Mahmoud Al-Qudah ◽  
Fedaa Hamadeh ◽  
Lo’ay Al-Momani ◽  
Sultan Abu-Orabi

A series of derivatives of trans-3-(2,4,6-trimethoxy phenyl)-4,5-dihydro isoxazolo-4,5-bis(aroylcarbohydrazide) and of trans-3-(2,4,6-trimethoxyphenyl)4,5-dihydroisoxazolo-4,5-bis[carbonyl-(4’phenyl)thiosemi- carbazide (9) were synthesized from trans-3-(2,4,6-trimethoxyphenyl)-4,5-dihydro-4,5-bis(hydrazenocarbonyl) Isoxazole (8). The structures of the Compounds were elucidated by elemental and spectral (IR, NMR, and MS) analysis. The compound 9 show activity against some bacterial species. Whereas, no activity was observed for compounds 10a, 10b and 10c against all bacterial species. The antioxidant activity of new compounds has been screened. Compound 9 showed higher antioxidant activity using the DPPH and ATBS method.


2020 ◽  
Vol 5 (443) ◽  
pp. 85-91
Author(s):  
Ibrayev M.K., ◽  
◽  
Takibayeva A.T., ◽  
Fazylov S.D., ◽  
Rakhimberlinova Zh.B., ◽  
...  

This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.


2018 ◽  
Vol 21 (3) ◽  
pp. 204-214 ◽  
Author(s):  
Vesna Rastija ◽  
Maja Molnar ◽  
Tena Siladi ◽  
Vijay Hariram Masand

Aims and Objectives: The aim of this study was to derive robust and reliable QSAR models for clarification and prediction of antioxidant activity of 43 heterocyclic and Schiff bases dipicolinic acid derivatives. According to the best obtained QSAR model, structures of new compounds with possible great activities should be proposed. Methods: Molecular descriptors were calculated by DRAGON and ADMEWORKS from optimized molecular structure and two algorithms were used for creating the training and test sets in both set of descriptors. Regression analysis and validation of models were performed using QSARINS. Results: The model with best internal validation result was obtained by DRAGON descriptors (MATS4m, EEig03d, BELm4, Mor10p), split by ranking method (R2 = 0.805; R2 ext = 0.833; F = 30.914). The model with best external validation result was obtained by ADMEWORKS descriptors (NDB, MATS5p, MDEN33, TPSA), split by random method (R2 = 0.692; R2 ext = 0.848; F = 16.818). Conclusion: Important structural requirements for great antioxidant activity are: low number of double bonds in molecules; absence of tertial nitrogen atoms; higher number of hydrogen bond donors; enhanced molecular polarity; and symmetrical moiety. Two new compounds with potentially great antioxidant activities were proposed.


2020 ◽  
Vol 17 ◽  
Author(s):  
Rahele Bargebid ◽  
Ali Khalafi-Nezhad ◽  
Kamiar Zomorodian ◽  
Leila Zamani ◽  
Ali Ahmadinejad ◽  
...  

Introduction: Mannich reaction is a typical example of a three-component condensation reaction and the chemistry of Mannich bases has been the matter of search by researchers. Here an efficient procedure for the synthesis of some new Mannich derivatives of simple phenols is described. Methods: In this procedure a microwave-assisted and solvent less condensation were done between different phenols, secondary amines and paraformaldehyde. The reactions proceed in the presence of catalytic amount of nano ZnO and tetrabutylammonium bromide (TBAB) in excellent yields. 10 new compounds were synthesized (A1-A10). Chemical structures of all new compounds were confirmed by different spectroscopic methods. We optimized the chemical reactions in different conditions. Optimization reactions were done in the presence of different mineral oxides, different amount of TBAB and also different solvents. Nano ZnO and TBAB in catalytic amounts and solvent free conditions were the best conditions. All the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated against some Candida, filaments fungi, gram positive and gram negative bacteria by broth micro dilution method as recommended by CLSI. Results: The result showed that compounds A2, A3 and A4 against most of the tested Candida species and compounds A5 and A7 against C. parapsilosis and C. tropicalis, exhibited considerable antifungal activities. Also Compounds A8 and A10 showed desirable antifungal activities against C. neoformance and C. parapsilosis, respectively. The antibacterial activities of the synthesized compounds were also evaluated. Compounds A6 - A10 against E. Fecalis and compounds A5, A7, A9 and A10 against P. aeruginosa showed desirable antibacterial activities. Discussion: We have synthesized some new Mannich adducts of poly-hydroxyl phenols in the presence of nano-ZnO as a reusable catalyst, with the hope of discovering new lead compounds serving as potent antimicrobial agents. The advantages of this method are generality, high yields with short reaction times, simplicity, low cost and matching with green chemistry protocols. The antimicriobial studies of Mannich derivatives of phenols showed desirable results in vitro.


1998 ◽  
Vol 63 (3) ◽  
pp. 293-298
Author(s):  
Vladislav Holba

The solubilities of cesium dianilinetetraisothiocyanatochromate(III) in water as well as in aqueous methanol, isopropyl alcohol, tert-butyl alcohol and acetonitrile were measured as a function of temperature and solvent composition. The Gibbs energies, enthalpies and entropies of transfer of the salt from water to the given solvents have been evaluated from experimental data. The contribution of [Cr(C6H5NH2)2(NCS)4]- ion to the Gibbs energy of transfer of the investigated salt has been calculated using the tetraphenylarsonium tetraphenylborate (TATB) reference electrolyte assumption.


2021 ◽  
Vol 11 (3) ◽  
pp. 1180
Author(s):  
Kinga Paruch ◽  
Łukasz Popiołek ◽  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Malm ◽  
...  

Bacterial infections, especially those caused by strains resistant to commonly used antibiotics and chemotherapeutics, are still a current threat to public health. Therefore, the search for new molecules with potential antimicrobial activity is an important research goal. In this article, we present the synthesis and evaluation of the in vitro antimicrobial activity of a series of 15 new derivatives of 4-methyl-1,2,3-thiadiazole-5-carboxylic acid. The potential antimicrobial effect of the new compounds was observed mainly against Gram-positive bacteria. Compound 15, with the 5-nitro-2-furoyl moiety, showed the highest bioactivity: minimum inhibitory concentration (MIC) = 1.95–15.62 µg/mL and minimum bactericidal concentration (MBC)/MIC = 1–4 µg/mL.


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