Transition Met Chem (2013) 38:481–488
483
the absence and presence of the oxovanadium complex
d6): 13.70 (br s, 1H, COOH), 10.31 (s, 1H, OH), 8.62 (s,
1H, –CH=N–), 8.26 (d, 1H, ArH), 7.90 (s, 1H, ArH), 7.68
(d, 1H, ArH), 7.22 (m, 1H, ArH), 7.10 (d, 1H, ArH), 6.73
[
20 lM] as a function of the temperature. The temperature
-
1
was scanned from 50 to 90 °C at a speed of 5 °C min
.
(d, 1H, ArH), 6.50 (t, 1H, ArH).
Photoinduced cleavage of pBR322 DNA
Synthesis of [VO(NOSAA)(bpy)] (1)
The cleavage of supercoiled pBR322 DNA by the com-
plexes was studied by gel electrophoresis; pBR322 DNA
3
A solution of NOSAA (0.1430 g, 0.5 mmol) in 100 cm of
0
(
0.1 lg) was treated with the oxovanadium complex in
buffer B. The samples were analyzed by electrophoresis for
.5 h at 85 V on 0.8 % agarose gel in TBE (89 mM Tris–
absolute methanol with 2,2 -bipyridyl (0.0780 g, 0.5 mmol)
was refluxed at 80 °C under argon for 1 h. After dissolution,
1
VO(acac) (0.1325 g, 0.5 mmol) in absolute methanol
2
3
(10 cm ) was added dropwise to this mixture. After refluxing
borate acid, 2 mM EDTA, pH = 8.3). The gel was stained
with 1 lg/mL ethidium bromide and photographed on an
Alpha Innotech IS-5500 fluorescence, chemiluminescence,
and visible imaging system [7, 8, 22–24].
for another 4 h, the reddish-brown precipitate was isolated
from the hot solution, washed with absolute methanol, and
dried in vacuo. Yield: 0.1579 g, 62.3 %. Anal. Calcd. for
C H N O V: C, 56.8; H, 3.2; N, 11.1 %; Found: C, 56.2; H,
2
4 16 4 6
?
Cytotoxicity assays
3.1; N, 11.0 %. ES-MS (CH OH, m/z): 508.0 ([M ? H] ).
3
-1
IR (KBr)(mmax/cm ): 3,338 (w) (ArH), 3,082(w) (ArH),
1,635 (vs) (C=N ? C=C), 1,599 (s) (C=C),1,387 (s), 1,357
The effects of the complexes on the growth of myeloma
cells (Ag8.653) were determined by MTT dye assay. The
compounds were dissolved in DMSO and diluted with
RPMI 1,640 to the required concentrations prior to use.
The control well was prepared by the addition of culture
medium (100 lL). Wells containing culture medium
without cells were used as blanks. Myeloma cells with a
(s), 1,320 (vs) (NO ) 1,204(w) (C–O), 1,102 (s), 964 (s)(VO),
2
893 (m), 868 (m), 768 (m), 663(m), 581 (w), 555 (m), 508
1
(m). H NMR (500 MHz, DMSO-d ):8.69 (s, 1H, –CH=N–),
6
8.30–8.40 (br m, 5H, ArH), 7.90–7.97 (br m, 5H, ArH),
7.40–7.55 (br m, 5H, ArH). Magnetic moment: l : 1.73BM.
eff
4
0
density of 2 9 10 cells per well were precultured into
Synthesis of [VO(NOSAA)(4,4 -dimebpy)] (2)
9
6-well microtiter plates for 48 h at 37 °C, 5 % CO . Upon
2
completion of the incubation, stock MTT dye solution was
added to each well. After 4-h incubation, a solution con-
taining N,N-dimethylformide (50 %) sodium dodecyl sul-
fate (20 %) was added to solubilize the MTT formazan.
The cell viability was determined by measuring the
absorbance of each well at 490 nm using a Multiskan
ASCENT microplate reader. IC50 values were determined
by plotting the percentage viability versus concentration on
a logarithmic graph and reading off the concentration at
which 50 % of cells remained viable relative to the control.
This complex was synthesized by a similar procedure as for
0
complex (1), but with 4,4 -dimebpy (0.0920 g, 0.5 mmol)
in place of bpy. Yield: 0.1571 g, 59 %. Anal. Calcd. For
C H N O V: C, 58.3; H, 3.7; N, 10.5 %; Found: C, 57.5;
2
6 20 4 6
H, 3.7; N, 10.0 %. ES-MS (CH OH, m/z): 536.1
3
?
-1
([M ? H] ). IR (KBr)(mmax/cm ): 3,064 (w) (ArH), 1,630
(vs) (C=N ? C=C), 1,603 (s) (C=C), 1,546 (m), 1,320 (vs)
(NO ), 1,249 (s) (C–O), 1,207 (w), 1,182 (w), 1,159 (w),
2
972 (s) (VO), 838 (m), 801 (m), 721 (m), 664 (m), 556 (w),
1
410 (w). H NMR (500 MHz, DMSO-d ): 8.53 (s, 1H,
6
–CH = N–), 8.20–8.23 (br m, 4H, ArH), 7.30–7.69 (br m,
Synthesis of (NOSAA)
4H, ArH), 7.27–7.28 (br m, 5H, ArH), 2.40 (s, 6H, CH3).
Magnetic moment: l : 1. 71BM.
eff
A solution of anthranilic acid (0.6850 g, 5 mmol) in
3
absolute methanol (10 cm ) was slowly added to a solution
Synthesis of [VO(NOSAA)(phen)] (3)
of 2-hydroxy-5-nitrosalicylaldehyde (0.8350 g, 5 mmol) in
3
absolute methanol (30 cm ). The mixture was stirred at
This complex was synthesized by a similar procedure as
for the complex (1), but with phen (0.090 g, 0.5 mmol) in
place of bpy. Yield: 0.1739 g, 66 %. Anal. Calcd. For
C H N O V: C, 58.8; H, 3.0; N, 10.6 %; Found: C, 58.5;
50 °C for 3 h gave a red precipitate, which was filtered off
and washed with diethyl ether, then dried in vacuo. Yield:
1
.0063 g, 70 %. Anal. Calcd. for C H N O : C, 58.7; H,
14 10 2 5
26 16 4 6
?
3
.5; N, 9.8 %; Found: C, 58.6; H, 3.5; N, 9.7 %. ES-MS
?
H, 3.0; N, 9.1 %. ES-MS (CH OH, m/z): 532.1 ([M ? H] ).
3
-1
IR (KBr)(mmax/cm ): 3,067 (w) (ArH), 1,633 (vs)
(C=N ? C=C), 1,594 (s) (C=C), 1,497 (m) (C=C), 1,354
-1
CH OH, m/z): 287.3 ([M ? 1] ). IR (KBr)(mmax/cm ):
(
3
3
,440 (br) (OH), 3,083 (m, ArH), 1,710 (s) (COOH), 1,638
vs) (C=N ? C=C), 1,609 (s) (C=C), 1,453 (m) (C=C),
,384 (m), 1,332 (vs) (NO ), 1,246 (vs) (C–O), 897 (s), 831
(
(s) (NO ), 1,225 (s) (C–O), 1,147 (w), 1,101 (m), 972
2
1
(s) (VO), 843 (m), 727 (m), 662 (m), 559 (w), 411 (w). H
1
2
1
(
vs), 753 (s), 688 (m), 631(s). H NMR (500 MHz, DMSO-
NMR (500 MHz, DMSO-d ): 9.10 (s, 1H, –CH=N–),
6
123