Synthesis, Crystal Structure, DFT Studies and Evaluation of the Antioxidant Activity of 3,4-Dimethoxybenzenamine Schiff Bases

Abstract

Schiff bases of 3,4-dimethoxybenzenamine 1 – 25 were synthesized and evaluated for their antioxidant activity. All the synthesized compounds were characterized by various spectroscopic techniques. In addition, the characterizations of compounds 13 , 15 and 16 were supported by crystal X-ray determinations and their geometrical parameters were compared with theoretical DFT calculations at the B3LYP level of theory. Furthermore, the X-ray crystal data of two non-crystalline compounds 8 and 18 were theoretically calculated and compared with the practical values of compounds 13 , 15 , 16 and found a good agreement. The compounds showed good DPPH scavenging activity ranging from 10.12 to 84.34 μM where compounds 1 – 4 and 6 showed stronger activity than the standard n -propyl gallate. For the superoxide anion radical assay, compounds 1 – 3 showed better activity than the standard.

Synthesis of novel derivatives of oxindole, their urease inhibition and molecular docking studies

“…The (E)-4-((6-chloro-2-oxoindolin-3-ylidene)methyl)benzohydrazide was treated with different acetophenones and aryl aldehydes in the presence of acetic acid to give desired products (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) Scheme-2. …”

“…Benzohydrazones were recently reported to possess diuretic [19], antioxidant [20][21][22][23], antiglycation [24][25][26] α-glucosidase [27] and antileishmanial [28] activities.…”

Synthesis of 3,4,5-trihydroxybenzohydrazone and evaluation of their urease inhibition potential

“…Benzohydrazones having heterocyclic rings were reported to have antiglycation, anticonvulsant, Phosphodiesterase-1 inhibitors, antiproliferative, antifungal and anti-HIV activities (Kabak et al, 1999;Ku¨c¸u¨kgu¨zel et al, 2004;Khan et al, 2014a;Jamil et al, 2015;Pandeya et al, 1999). Several benzohydrazones reported interesting bioactivities, such as antifungal, anticonvulsant, anti-inflammatory, antibacterial, antimalarial, antiplatelets, analgesic, antituberculosis, antioxidant (Loncle et al, 2004;Ku¨c¸u¨kgu¨zel et al, 2003;Todeschini et al, 1998;Melnyk et al, 2006;Lima et al, 2000;Cunha et al, 2003;Kaymakc¸ıog˘lu et al, 2006;Aziz et al, 2014), antileishmanial, insecticidal, immunoconjugates, antimycobacterial, adriamycin proteinase inhibition and activity against protozoan parasite (Sawada et al, 2003;Taha et al, 2013;Ku¨c¸u¨kgu¨zel and Rollas, 2002;Greenfield et al, 1990;Caffery et al, 2002). Other benzohydrazone derivatives have reported b-glucuronidase ) and aglucosidase inhibition activity .…”

Antiglycation and antioxidant potential of novel imidazo[4,5-b]pyridine benzohydrazones

“…Interestingly, imidazole moiety is also considered significant for antiglycation activity as it was found that, free amino group of imidazole ring will competes with amine side groups of proteins in the presence of reactive dicarbonyl compounds (Brownson and Hipkiss, 2000). Benzohydrazides are reported to possess a broad variety of biological activities such as antiglycation (Khan et al, 2013a, b andKhan et al, 2015;Jamil et al, 2015), antioxidant (Aziz et al, 2014;Khan et al, 2012), antileishmanial , antibacterial (Imran et al, 2014), b-glucuronidase , urease and c) and a-glucosidase (Taha et al, 2015f).…”