New Compounds. Derivatives of 3-Methoxy-4-nitrobenzoic Acid and 3-Carbomethoxy-4-nitrobenzoic Acid

1952 ◽  
Vol 74 (19) ◽  
pp. 4969-4969
Author(s):  
Theodor Liss
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.


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.


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.


1979 ◽  
Vol 57 (5) ◽  
pp. 385-395 ◽  
Author(s):  
Michael M. Talgoy ◽  
Harry W. Duckworth

Evidence is presented that a number of derivatives of adenylic acid may bind to the allosteric NADH binding site of Escherichia coli citrate synthase. This evidence includes the facts that all the adenylates inhibit NADH binding in a competitive manner and that those which have been tested protect an enzyme sulfhydryl group from reaction with 5,5′-dithiobis-(2-nitrobenzoic acid) in the same way that NADH does. However, whereas NADH is a potent inhibitor of citrate synthase, most of the adenylates are activators. The best activator, ADP-ribose, increases the affinity of the enzyme for the substrate, acetyl-CoA, and saturates the enzyme in a sigmoid manner. A fluorescence technique, involving the displacement of 8-anilino-1-naphthalenesulfonate from its complex with citrate synthase, is used to obtain saturation curves for several nucleotides under nonassay conditions. It is found that acetyl-coenzyme A, coenzyme A, and ADP-ribose all bind to the enzyme cooperatively, and that the binding of each becomes tighter in the presence of KCl the activator, and oxaloacetic acid (OAA), the second substrate. Another inhibitor, α-ketoglutarate, can compete with OAA in the absence of KClbut not in its presence. The nature of the allosteric site of citrate synthase, and the modes of action of several activators and inhibitors, are discussed in the light of this evidence.


2018 ◽  
Vol 10 (1) ◽  
pp. 153
Author(s):  
Iniobong E. Ante ◽  
Sherifat A Aboaba ◽  
Hina Siddiqui ◽  
Muhammad A Bashir ◽  
Muhammad I Choudhary

A new series of 2-aminopyridine derivatives were synthesised. N-acylation of 2-amino-3-chloro-5-(trifluoromethyl) pyridine and 2-amino-5-(trifluoromethyl) pyridine with series of acid chlorides afforded a total of fourteen (14) amide compounds. The structures of the new compounds have been established by their IR, NMR and mass spectra data. All the compounds were tested for their activity against four (4) multi-drug resistant (MDR) bacteria Staphylococcus aureus strains using microplate alamar blue assay. The MDR-Staphylococcus aureus strains employed for this study were Epidermic Methicilin Resistant Staphylococcus aureus (EMRSA-17), Methicilin Resistant Staphylococcus aureus (MRSA-252), Epidermic Methicilin Resistant Staphylococcus aureus (EMRSA-16) and Pakistani Drug resistant clinical isolate of Staphylococcus aureus (PRSA). Other bacteria strains also used include Escherichia coli (ATCC 2592), Shigella flexenari (ATCC 12022), Staphylococcus aureus (NCTC 6571) and Pseudomonas aeruginosa (NCTC 10662). The synthesised compounds exhibited very good activity against the four MDR-Staphylococcus aureus strains of which most of the compounds showed higher potencies for inhibiting the growth of the strains than vancomycin, the standard drug employed. The compounds reported here may serve as the starting point for the design and development of MDR-S.aureus inhibitors as antibacterial agents.


Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 99 ◽  
Author(s):  
Marian Frank ◽  
Ferhat Özkaya ◽  
Werner Müller ◽  
Alexandra Hamacher ◽  
Matthias Kassack ◽  
...  

The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4–19). The addition of several inorganic salts to the rice medium mainly influenced the accumulation of these secondary metabolites. Fermentation of the fungus on white bean medium yielded the new waspergillamide B (1) featuring an unusual p-nitrobenzoic acid as partial structure. Moreover, two new compounds, ochraspergillic acids A and B (2 and 3), which are both adducts of dihydropenicillic acid and o- or p-aminobenzoic acid, were isolated from the co-culture of the fungus with Bacillus subtilis. Compound 2 was also detected in axenic fungal cultures following the addition of either anthranilic acid or tryptophan to the rice medium. The structures of the new compounds were established by 1D and 2DNMR experiments as well as from the HRMS data. The absolute configuration of 1 was elucidated following hydrolysis and derivatization of the amino acids using Marfey’s reagent. Viomellein (9) and ochratoxin B (18) exhibited strong cytotoxicity against the A2780 human ovarian carcinoma cells with IC50 values of 5.0 and 3.0 µM, respectively.


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.


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