Nitroguanylhydrazones of Aldehydes: Their Antitubercular Activity, Ultraviolet Absorption Spectra and Structure*†

Novel Aminoguanidine Hydrazone Analogues: From Potential Antimicrobial Agents to Potent Cholinesterase Inhibitors

“…In addition to bioactive AG and 1,3-diaminoguanidine derivatives summarized briefly in Introduction section, we utilize knowledge about antimicrobial nitrofuran drugs nitrofurantoin and nitrofurazone (antibacterial, antifungal, antiprotozoal agents), anti-MRSA 5-nitrothiophene analogues of antimicrobial drug nifuroxazide [21], antibiotic robenidine used mainly in control of Coccidia infections in poultry and rabbit suppression also drug-resistant Gram-positive cocci [22], topical antibacterial drug ambazone with anticancer properties [23], antiviral agent methisazone [24], as well as our recent 3,5-dihalogenosalicylidene aminobenzoic acid derivatives identified as potent compounds against Gram-positive bacteria, yeasts and molds [17,18]. Nitroaminoguanidines are effective as inhibitors of phytopathogenic fungi [25] and mycobacteria [26].…”

Acidic and Basic Dissociation Constants and Structure

“…In the case of these guanidine derivatives, the main contributing form to the resonance hybrid is not a form with a separation of charge +nh2 nh2 H2N-C-N-B but a form without a separation of charge H2N-C=N-B which is more stable. Recently it has been shown from chemical, dipole moment, dissociation constant and spectra data that nitroguanidine, nitroaminoguanidine, nitrosoguanidine, 2-nitriminoimidazolidine, l-nitro-2-nitriminoimidazolidine, and azo-bis(nitroformamidine) have structures of this type which are properly designated nitroimines (3)(4)(5)(6)(7)(8). In these cases the nitroimine form is more stable not only because it does not have a separation of charge, but also because the double bond is now conjugated with the nitro nh2 0 group H2N-C=N-N->0 and additional stabilization results from this conjugation.…”