Synthesis and biological evaluation of α-triazolyl chalcones as a new type of potential antimicrobial agents and their interaction with calf thymus DNA and human serum albumin.

A series of α-triazolyl chalcones were efficiently synthesized. Most of the prepared compounds showed effective antibacterial and antifungal activities. Noticeably, α-triazolyl derivative 9a exhibited low MIC value of 4 µg/mL against MRSA and Micrococcus luteus, which was comparable or even superior to reference drugs. The further research revealed that compound 9a could effectively intercalate into Calf Thymus DNA to form 9a-DNA complex which might block DNA replication to exert their powerful antimicrobial activities. Competitive interactions between 9a and metal ions to Human Serum Albumin (HSA) suggested the participation of Fe(3+), K(+) and Mg(2+) ions in 9a-HSA system could increase the concentration of free 9a, shorten its storage time and half-life in the blood, thus improving its antimicrobial efficacy.

(Z)-1-[4-Fluoro-2-(pyrrolidin-1-yl)phen-yl]-3-phenyl-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-one.

In the title mol-ecule, C(21)H(19)FN(4)O, the triazole ring forms dihedral angles of 67.0 (1) and 59.6 (1)° with the phenyl and fluoro-substituted benzene rings, respectively. The dihedral angle between the phenyl ring and the fluoro-substituted benzene ring is 79.1 (1)°. The pyrrolidine ring is in a half-chair conformation. In the crystal, weak C-H⋯O and C-H⋯N hydrogen bonds connect mol-ecules into layers parallel to (001).

7-(6-Bromo-hex-yloxy)-4-methyl-2H-chromen-2-one.

In the title mol-ecule, C(16)H(19)BrO(3), all non-H atoms apart from the Br atom are approximately coplanar, with a maximum deviation of 0.242 (4) Å. The C-C-C-Br torsion angle is 66.5 (4)°.

(Z)-3-(4-Chloro-phen-yl)-1-(2,4-difluoro-phen-yl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-one.

The asymmetric unit of the title compound, C(17)H(10)ClF(2)N(3)O, contains three independent mol-ecules. In each mol-ecule, the C=C bond has a cis conformation with respect to the triazole and chloro-phenyl groups. The dihedral angles formed by the triazole ring with the diflurophenyl and chloro-phenyl benzene rings, respectively, are 20.10 (14) and 73.22 (15), 25.31 (15) and 84.44 (15), and 16.44 (13) and 61.72 (14)° in the three mol-ecules while the dihedral angles between the benzene rings are 66.54 (13), 85.82 (12) and 58.37 (12)°.

(Z)-1,3-Bis(4-chloro-phen-yl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-one.

In the title mol-ecule, C(17)H(11)Cl(2)N(3)O, the C=C bond connecting the triazole and 4-chloro-phenyl groups adopts a Z geometry. The dihedral angles formed by the triazole ring and the 4-chloro substituted benzene rings are 67.3 (1) and 59.1 (1)°. The dihedral angle between the two benzene rings is 73.5 (1)°.

(Z)-1-(2,4-Difluoro-phen-yl)-3-(4-fluoro-phen-yl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-one.

In the title mol-ecule, C(17)H(10)F(3)N(3)O, the C=C bond connecting the triazole ring and 4-fluoro-phenyl groups adopts a Z conformation. The triazole ring forms dihedral angles of 15.3 (1) and 63.5 (1)°, with the 2,4-difluoro-substituted and 4-fluoro-substituted benzene rings, respectively. The dihedral angle between the two benzene rings is 51.8 (1)°.