DOI: 10.3109/14756366.2012.752363
Tetrazole derivatives
3
For C10H9ClN4OS calculated: 44.70% C, 3.38% H and 20.85% 1H-NMR (500 MHz, DMSO-d6): ꢁ 4.01 (3H, s, CH3), 4.96 (2H, s,
N; found 44.72% C, 3.38% H and 21.00% N.
CH2), 7.64 (1H, d, J ¼ 8.60 Hz, Ar-H), 7.68 (1H, dd, J1 ¼ 2.05 Hz,
J2 ¼ 8.52 Ar-H), 7.97 (1H, s, Ar-H).
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.38, 43.73, 130.32, 130.74,
133.32, 133.68, 134.01, 138.96, 154.32 and 192.14.
MS (FAB) [M þ 1]þ: m/z 304.
1-(4-Florophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]ethanone (8)
IR (KBr) ꢀmax (cmꢀ1): 1683 (C¼O), 1579 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 4.08 (3H, s, CH3), 5.1 (2H, s,
CH2), 7.42 (2H, d, J ¼ 8.02 Hz, Ar-H), 8.15 (2H, d, J ¼ 8.04 Hz,
Ar-H).
For C10H8Cl2N4OS calculated: 39.62% C, 2.66% H and
18.48% N; found 39.67% C, 2.68% H and 18.52% N.
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.37, 41.93, 117.06, 117.24,
132.80, 132.87, 154.62, 165.88, 167.89 and 192.97.
MS (FAB) [M þ 1]þ: m/z 253.
1-(3,4-Dichlorophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]etha-
none (14)
IR (KBr) ꢀmax (cmꢀ1): 1669 (C¼O), 1571 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 4.01 (3H, s, CH3), 5.11 (2H, s,
CH2), 7.88 (1H, d, J ¼ 8.46 Hz, Ar-H), 8.02 (1H, d, J ¼ 9.05 Hz,
Ar-H), 8.29 (1H, s, Ar-H).
For C10H9FN4OS calculated: 47.61% C, 3.60% H and 22.21%
N; found 47.64% C, 3.58% H and 22.19% N.
1-(4-Bromophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]ethanone (9)
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.40, 41.78, 129.69, 131.68,
132.52, 133.21, 136.53, 138.06, 154.45 and 192.82.
MS (FAB) [M þ 1]þ: m/z 304.
IR (KBr) ꢀmax (cmꢀ1): 1684 (C¼O), 1580 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 4.00 (3H, s, CH3), 5.1 (2H, s,
CH2), 7.80 (2H, d, J ¼ 8.60 Hz, Ar-H), 7.97 (2H, d, J ¼ 8.6 Hz,
Ar-H).
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.36, 41.92, 129.37, 130.33,
131.78, 133.25, 154.65 and 193.69.
For C10H8Cl2N4OS calculated: 39.62% C, 2.66% H and
18.48% N; found 39.60% C, 2.63% H and 18.53% N.
Biology
MS (FAB) [M þ 1]þ: m/z 314.
For C10H9BrN4OS calculated: 38.85% C, 2.90% H and 17.89%
N; found 38.82% C, 2.98% H and 17.90% N.
Anticandidal activity
The antifungal properties of compounds 1–14 were evaluated by
the broth microdilution method according to the modified
National Committee for Clinical Laboratory Standards
(NCCLS) M27-A2 standard procedure44. Tested candida strains
were Candida albicans (isolate, obtained from Department of
Microbiology, Faculty of Medicine, Osmangazi University,
Eskisehir, Turkey), C. albicans (ATCC 90028), C. glabrata
(isolate-1 obtained from Department of Microbiology, Faculty of
Medicine, Osmangazi University, Eskisehir, Turkey), C. tropicalis
(NRRL Y-12968), C. krusei (NRRL Y-7179), C. parapsilosis
(NRRL Y-12696), C. albicans (NRRL Y-12983), C. glabrata
(isolate-2 obtained from Department of Microbiology, Faculty of
1-(4-Nitrophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]ethanone (10)
IR (KBr) ꢀmax (cmꢀ1): 1669 (C¼O), 1570 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 4.02 (3H, s, CH3), 5.18 (2H, s,
CH2), 8.3 (2H, d, J ¼ 8.95 Hz, Ar-H), 8.4(2H, d, J ¼ 8.87 Hz, Ar-H).
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.40, 42.18, 125.17, 131.16,
141.06, 151.65, 154.47 and 193.81.
MS (FAB) [M þ 1]þ: m/z 280.
For C10H9N5O3S calculated: 43.01% C, 3.25% H and 25.08%
N; found 43.05% C, 3.27% H and 25.04% N.
1-(2,4-Dimethylphenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]etha-
none (11)
Medicine,
Ketoconazole was used as positive control.
Osmangazi
University,
Eskisehir,
Turkey).
IR (KBr) ꢀmax (cmꢀ1): 1685 (C¼O), 1582 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 2.34 (3H, s, C–CH3), 2.37 (3H,
s, C–CH3), 3.99 (3H, s, N–CH3), 4.98 (2H, s, CH2), 7.17 (2H, s,
Ar-H), 7.20 (1H, d, J ¼ 8.00 Hz, Ar-H), 7.88 (1H, d, J ¼ 7.91,
Ar-H).
Stock solutions were prepared in dimethylsulfoxide (DMSO,
Carlo-Erba, Val de Reuil, France). Overnight grown Candida
suspensions in Mueller–Hinton Broth were standardized to
106 CFU/ml using suspension turbidity detector (BioSan, Riga,
Latvia) adjusted to McFarland no. 0.5. Different from the NCCLS
method, 100 mL of each Candida suspension was added into the
wells. Sterile distilled water and medium servedas a positive growth
control. The first well without turbidity was assigned as the
minimum inhibitory concentration (MIC, mg/mL). After incuba-
tion at 37 ꢁC for 18–24 h, antifungal activity was detected by
spraying of 0.5% TTC (triphenyl tetrazolium chloride, Merck)
aqueous solution. MIC was defined as the lowest concentration of
compounds that inhibited visible growth, as indicated by the TTC
staining.
13C-NMR (125 MHz, DMSO-d6): ꢁ 21.46, 26.95, 34.31, 43.82,
127.75, 131.11, 133.81, 133.96, 139.58, 143.85, 154.78 and 196.73.
MS (FAB) [M þ 1]þ: m/z 263.
For C12H14N4OS calculated: 54.94% C, 5.38% H and 21.36%
N; found 54.96% C, 5.37% H and 21.34% N.
1-(2,4-Dichlorophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]etha-
none (12)
IR (KBr) ꢀmax (cmꢀ1): 1677 (C¼O), 1574 (C¼N).
1H-NMR (500 MHz, DMSO-d6): ꢁ 3.99 (3H, s, CH3), 4.96 (2H, s,
CH2), 7.65 (1H, dd, J1 ¼ 2.04 Hz, J ¼ 10.51 Hz, Ar-H), 7.81 (1H,
d, J ¼ 2.00 Hz, Ar-H), 7.92 (1H, d, J ¼ 8.5 Hz, Ar-H).
13C-NMR (125 MHz, DMSO-d6): ꢁ 34.37, 43.83, 128.94, 131.56,
132.80, 133.01, 136.16, 138.38, 154.42 and 192.64.
MS (FAB) [M þ 1]þ: m/z 304.
Cytotoxicity
The cytotoxic activities of the tested compounds were determined
by cell proliferation analysis using the standard 3-(4,5-
dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)
assay45,46. Mouse embryonic fibroblast (NIH/3T3) cells were
cultured in 96-well flat-bottom plates at 37 ꢁC for 24 h
(2 ꢂ 104 cells per well). All the compounds were dissolved in
DMSO individually and added to culture wells at varying
concentrations (0.5–500 mg/mL), the highest final DMSO con-
centration was under 0.1%. After 24 h of drug incubation at 37 ꢁC,
20 mL MTT solution (5 mg/mL MTT powder in PBS) was added
For C10H8Cl2N4OS calculated: 39.62% C, 2.66% H and
18.48% N; found 39.65% C, 2.67% H and 18.51% N.
1-(2,5-Dichlorophenyl)-2-[(1-methyl-1H-tetrazol-5-yl)thio]etha-
none (13)
IR (KBr) ꢀmax (cmꢀ1): 1684 (C¼O), 1590 (C¼N).