Synthesis and Biological Activities of N-Alkyl Derivatives of o-,m-,and p-Nitro (E)-4-Azachalcones and Stereoselective Photochemistry in Solution,with Theoretical Calculations

摘要

The N-alkyl derivatisation and photochemical dimerisation of 3 o-,m-,and p-nitro substituted 4-azachalcones (1-3) yielded 3 new o-,m-,and p-nitro substituted (E)-N-decyl-4-azachalcomum bromides,(2E)-l-(2-nitrophenyl)-3-(N-decyl-4-pyridinium bromide)-2-propen-l-one (4),(2.E)-l-(3-nitrophenyl)-3-(N-decyl-4-pyridinium bromide)-2-propen-l-one (5),and (2ZS)-l-(4-mtrophenyl)-3-(N-decyl-4-pyridinium bromide)-2-propen-l-one (6),and 3 new dimers in solution,(l beta,2 alpha)-di-(3-nitrobenzoyl)-(3 beta,4 alpha)-di-(4-pyridinyl)cyclobutane (7),(l beta,2 alpha)-di-(4-nitrobenzoyl)-(3 beta,4 alpha)-di-(4-pyridinyl)cyclobutane (8a),and (l beta,2 beta)-di-(4-nitrobenzoyl)-(3 beta,4 alpha)-di-(4-pyridinyl)cyclobutane (8b),stereoselectively.The monomeric compounds showed good antimicrobial activity against test micro-organisms.The most sensitive micro-organisms were Gram-positive bacteria.The monomers also showed high antioxidant activity,while the dimerisation products 7-8a,b were less active. Compound 6 was found to have similar or even higher activity when compared to the standard antioxidants Trolox~R and vitamin C,respectively.The possible dimerisation products of compounds 1-3 were calculated theoretically. Experimental and theoretical calculations showed that delta-truxinic type dimer is the most stable isomer.