3952
K. Shanab et al. / Bioorg. Med. Chem. Lett. 20 (2010) 3950–3952
734 cmÀ1. MS: m/z (% relative intensity) 269 (M+, 1), 225 (1), 211 (1), 128 (1),
101 (7), 71 (15), 58 (100), 42 (9).
while ring systems containing one nitrogen (with the exception of
2) exhibit low antiproliferative activity.
Surprisingly, it was demonstrated by standard DNA intercalat-
ing UV experiments that the most active compound 3a does not
intercalate into DNA (as exemplified in Fig. 2).15
Compound 1b: 1H NMR (CDCl3): d (ppm): 1.89–2.03 (m, 2H), 2.23 (t, J = 7.1 Hz,
2H), 2.91 (s, 6H), 4.47 (t, J = 5.6 Hz, 2H), 6.72 (d, J = 2.6 Hz, 1H), 7.07 (d,
J = 2.8 Hz, 1H), 7.88 (dd, J = 5.1 Hz und 0.8 Hz, 1H), 8.95 (d, J = 4.9 Hz, 1H), 9.32
(s, 1H). 13C NMR (CDCl3): d (ppm): 28.3, 45.2, 47.4, 55.6, 107.9, 118.7, 126.2,
129.0, 129.8, 132.6, 139.6, 148.4, 154.9, 174.2, 180.2. IR (KBr): mmax 1668, 1652,
As demonstrated earlier by the authors,7 oxime derivatives of
compound 2a with excellent antiproliferative activities were also
identified as not DNA binding. Comparing the activities for 3a
against RKOp27 with or without p27 induced cell cycle arrest sug-
gest, that a G2/M-phase cell cycle arrest (as displayed by e.g., tubi-
lin inhibitors) is not involved. However, the mode of action
remains to be elucidated.
1584, 1496, 1392, 1368, 1253, 1238, 1183, 1036, 931, 731 cmÀ1. MS: m/z (%
relative intensity) 283 (M+, 2), 211 (4), 141 (2), 101 (3), 84 (8), 77 (10), 58
(100), 42 (12).
Compound 2a: Mp = 148 °C. 1H NMR (CDCl3): d (ppm): 2.30 (s, 6H), 2.73 (t,
J = 6.5 Hz, 2H), 4.57 (t, J = 6.5 Hz, 2H), 6.77 (d, J = 2.8 Hz, 1H), 7.10 (d, J = 2.8 Hz,
1H), 7.94 (d, J = 4.9 Hz, 1H), 8.98 (d, J = 5.0 Hz, 1H), 9.37 (s, 1H). 13C NMR
(CDCl3): d (ppm): 45.6, 47.3, 59.5, 108.2, 118.8, 126.8, 128.7, 129.8, 132.1,
139.2, 148.4, 154.9, 175.4, 179.7. IR (KBr): mmax 1668, 1646, 1583, 1502, 1378,
1247 cmÀ1. MS: m/z (% relative intensity) 269 (M+, 1), 211 (1), 155 (1), 128 (3),
101 (1), 71 (6), 58 (100).
In conclusion, pyrrole annelated isoquinolines, quinazolines,
quinolines and quinoxalines were synthesized and characterized.16
These compounds were screened for cytotoxic activity against dif-
ferent cell lines. Compounds containing a quinazoline core exhib-
ited superior EC50 values compared with compounds containing
different positional isomers on nitrogen containing ring systems.
Quinazoline 3a does not intercalate into DNA, which suggests that
the cytotoxic effects underlie a different mechanism than classical
DNA intercalating agents. These results provide useful information
for further studies and for the development of an extended com-
pound library.
Compound 2b: 1H NMR (CDCl3): d (ppm): 1.88–2.06 (m, 2H), 2.21 (s, 6H), 2.26
(t, J = 6.8 Hz, 2H), 4.50 (t, J = 7.0 Hz, 2H), 6.75 (d, J = 2.4 Hz, 1H), 7.06 (d,
J = 2.7 Hz, 1H), 7.93 (d, J = 4.9 Hz, 1H), 8.97 (d, J = 4.9 Hz, 1H), 9.35 (s, 1H). 13C
NMR (CDCl3): d (ppm): 28.4, 45.2, 47.5, 55.7, 108.0, 118.7, 126.8, 128.8, 129.8,
132.1, 139.2, 148.4, 154.9, 175.2, 179.6. IR (KBr): mmax 3430, 2815, 1667, 1652,
1583, 1497, 1389, 1251 cmÀ1. MS: m/z (% relative intensity) 283 (M+, 1), 211
(13), 98 (26), 84 (12), 72 (16), 58 (100).
Compound 3a: Mp = 177–178 °C. 1H NMR (CDCl3): d (ppm): 2.23 (s, 6H), 2.67
(t, J = 6.37 Hz, 2H), 4.50 (t, J = 6.44 Hz, 2H), 6.79 (d, J = 2.64 Hz, 1H), 7.13 (d,
J = 2.78 Hz, 1H), 9.45 (s, 1H), 9.51 (s, 1H). 13C NMR. (CDCl3): d (ppm): 45.4, 47.2,
59.2, 109.0, 125.7, 129.0, 129.2, 132.8, 154.7, 156.8, 173.2, 177.9. IR (KBr): mmax
3092, 2761, 1670, 1566, 1498, 1372, 1249, 1040, 955 cmÀ1. MS: m/z (% relative
intensity) 270 (M+, 1), 226 (1), 120 (1), 106 (1), 79 (1), 65 (1), 58(100).
Compound 3b: Mp = 88 °C. 1H NMR (CDCl3): d (ppm): 1.97 (m, 2H), 2.23–2.31
(m, 8H), 4.52 (t, J = 6.94 Hz, 2H), 6.88 (d, J = 2.64 Hz, 2H), 7.15 (d, J = 2.66 Hz,
1H), 9.53 (s, 1H), 9.60 (s, 1H). 13C NMR (CDCl3): d (ppm): 28.3, 45.2, 47.6, 55.6,
References and notes
109.0, 125.9, 129.2, 129.5, 133.0 154.9, 157.0, 173.3, 178.1. IR (KBr): mmax 3116,
2805, 1656, 1548, 1498, 1404, 1371, 1254, 1192, 935 cmÀ1. MS: m/z (% relative
intensity) 284 (M+, 5), 213 (4), 212 (4), 149 (2), 84 (12), 72 (12), 59 (5), 58(100).
Compound 4a: Mp = 148–149 °C. 1H NMR (CDCl3): d (ppm): 2.29 (s, 6H), 2.72
(t, J = 6.50 Hz, 2H), 4.55 (t, J = 6.50 Hz, 2H), 6.85 (d, J = 2.78 Hz, 1H), 7.10 (d,
J = 2.78 Hz, 1H), 7.60 (dd, J = 4.67/7.83 Hz, 1H), 7.47 (dd, J = 1.70/7.90 Hz, 1H),
8.95 (dd, J = 1.70/4.62 Hz, 1H). 13C NMR (CDCl3): d (ppm): 45.6, 47.2, 59.5,
108.8, 126.7, 129.4, 129.6, 130.8, 132.2, 134.6, 149.5, 153.4, 174.7, 179.0. IR
1. Edan, G.; Morrissey, S.; Le Page, E. J. Neurol. Sci. 2004, 223, 35.
2. Dunn, C. J.; Goa, K. L. Drugs Aging 1996, 9, 122.
3. Frishman, W. H.; Sung, H. M.; Yee, H. C.; Liu, L. L.; Keefe, D.; Einzig, A. I.;
Dutcher, J. J. Curr. Probl. Cancer 1997, 21, 301.
4. Tomillero, A.; Moral, M. A. Methods Find. Exp. Clin. Pharmacol. 2009, 31, 661.
5. Mukherji, D.; Pettengell, R. Drugs Today (Barc.) 2009, 45, 797.
6. Cavalletti, E.; Crippa, L.; Mainardi, P.; Oggioni, N.; Cavagnoli, R.; Bellini, O.; Sala,
F. Invest. New Drugs 2007, 25, 87.
7. Shanab, K.; Pongprom, N.; Wulz, E.; Holzer, W.; Spreitzer, H.; Schmidt, P.;
Aicher, B.; Müller, G.; Günther, E. Bioorg. Med. Chem. Lett. 2007, 17, 6091.
8. Pongprom, N.; Bachitsch, H.; Bauchinger, A.; Ettefagh, H.; Haider, T.; Hofer, M.;
Knafl, H.; Slanz, R.; Waismeyer, M.; Wieser, F.; Spreitzer, H. Chem. Monthly
2010, 141, 53.
(KBr): m
max 3415, 1677, 1655, 1578, 1388, 1250, 940 cmÀ1. MS: m/z (% relative
intensity) 269 (M+, 1), 86 (2), 78 (2), 71 (12), 70 (2), 69 (2), 58 (100).
Compound 4b: Mp = 99 °C. 1H NMR (CDCl3): d (ppm): 1.94 (m, 2H), 2.13–2.24
(m, 8H), 4.44 (t, J = 6.75 Hz, 2H), 6.68 (d, J = 2.66 Hz, 1H), 7.02 (d, J = 2.26 Hz,
1H), 7.56 (dd, J = 4.66/6.94 Hz, 1H), 8.41 (d, J = 7.84 Hz, 1H), 8.89 (d, J = 4.56 Hz,
1H). 13C NMR (CDCl3): d (ppm): 28.3, 45.1, 47.3, 55.6, 108.5, 126.6, 129.3, 129.5,
9. Spreitzer, H.; Pichler, A.; Holzer, W.; Kratzel, M.; Slanz, R.; Koulouri, A.; Krenn,
P.; Parrer, U.; Szieber, P. Heterocycles 2001, 54, 111.
130.6, 132.2, 134.4, 149.4, 153.2, 174.3, 174.3. IR (KBr): mmax 3413, 2945, 1651,
1500, 1394, 1243, 936, 706 cmÀ1. MS: m/z (% relative intensity) 283 (M+, 6),
212 (5), 211 (7), 156 (2), 155 (2), 113 (2), 58(100).
10. Kitahara, Y.; Nakahara, S.; Tanaka, Y.; Kubo, A. Heterocycles 1992, 34, 1623.
11. Boger, D. L.; Duff, S. R.; Panek, J. S.; Yasuda, M. J. Org. Chem. 1985, 50, 5782.
12. Wu, Y.-L.; Chuang, C.-P.; Lin, P.-Y. Tetrahedron 2001, 57, 5543.
13. Schmidt, M.; Lu, Y.; Liu, B.; Fang, M.; Mendelsohn, J.; Fan, Z. Oncogene 2000, 19,
2423.
14. Scudiero, D. A.; Shoemaker, R. H.; Paull, K. D.; Monks, A.; Tierney, S.; Nofziger,
T. H.; Currens, M. J.; Seniff, D.; Boyd, M. R. Cancer Res. 1988, 48, 4827.
15. The UV absorption curve of compound 3a shows a complete overlay to an UV
absorption curve of compound 3a added to DNA. A second experiment using a
Compound 5a: Mp = 269 °C. 1H NMR (CDCl3): d (ppm): 2.25 (s, 6H), 2.69 (t,
J = 6.63 Hz, 2H), 4.53 (t, J = 6.62 Hz, 2H), 6.68 (d, J = 2.78 Hz, 1H), 7.04 (d,
J = 2.64 Hz, 1H), 7.54 (dd, J = 4.74/7.88 Hz, 1H), 8.40 (dd, J = 1.64/7.82 Hz, 1H),
8.88 (dd, J = 1.70/4.74 Hz, 1H). 13C NMR (CDCl3): d (ppm): 45.4, 47.2, 59.3,
107.8, 126.6, 128.4, 130.2, 130.3, 131.9, 134.5, 149.5, 153.3, 173.7, 179.0. IR
(KBr): mmax 3092, 2945, 2771, 1661, 1573, 1500, 1394, 1243 cmÀ1. MS: m/z (%
relative intensity) 269 (M+, 1), 78 (2), 71 (15), 70 (13), 59 (4), 58 (100).
Compound 5b: 1H NMR (CDCl3): d (ppm): 1.97 (m, 2H), 2.17–2.26 (m, 8H), 4.48
(t, J = 6.94 Hz, 2H), 6.69 (d, J = 2.66 Hz, 1H), 7.02 (d, J = 2.64 Hz, 1H), 7.55 (dd,
J = 4.72/7.76 Hz, 1H), 8.41 (dd, J = 1.58/7.76 Hz, 1H), 8.89 (dd, J = 1.70/4.60 Hz,
1H). 13C NMR (CDCl3): d (ppm): 28.2, 45.1, 47.6, 55.7, 107.6, 126.6, 128.5, 130.2,
compound concentration of 125
lmol and determining UV absorptions
between 230 nm and 350 nm shows again no shift in absorption maxima.
Using Acridinorange as reference compound, a shift in absorption maxima for
about 25 nm was observed. Set-up of DNA intercalation experiment: stock
solution of reference and test compounds up to 5 mM concentration in 5% (v:v)
DMSO or methanol were prepared. The compound solution was diluted
stepwise in reaction buffer (5 mM NaH2PO4, 5 mM Na2HPO4, 70 mM NaCl, pH
7) and a compound concentration resulting in absorbance [abs max] of approx.
1–2 was determined in 96 well UV plates (Costar, Acton, MA) between 350 nm
130.4, 132.0, 134.5, 149.6, 153.4, 173.6, 179.3. IR (KBr): mmax 2943, 2818, 2767,
1663, 1578, 1501, 1399, 1240, 1064, 939 cmÀ1. MS: m/z (% relative intensity)
283 (M+, 2), 212 (6), 211 (10), 95 (4), 85 (8), 84 (98), 81 (11), 71 (4), 69 (19), 59
(5), 58(100).
Compound 6a: Mp = 189–190 °C. 1H NMR (CDCl3): d (ppm): 2.29 (s, 6H), 2.74
(t, J = 6.57 Hz, 2H), 4.59 (t, J = 6.63 Hz, 2H), 6.86 (d, J = 2.66 Hz, 1H), 7.17 (d,
J = 2.66 Hz, 1H), 8.91 (s, 2H). 13C NMR (CDCl3): d (ppm): 45.4, 47.3, 59.2, 109.0,
and 600 nm using
a Spectramax 190 plus reader (Molecular Devices,
Sunnyvale, CA). Finally, curves of the determined compound test
concentration using reaction buffer with or without 2 mg/ml (w:v) calf
thymus DNA (Sigma–Aldrich Corp., St. Louis, MO) were compared.
129.3, 130.2, 133.0, 145.5, 145.9, 147.4, 147.5, 172.5, 177.7. IR (KBr): mmax 1664,
1500, 1396, 1254, 1191, 1084, 994 cmÀ1. MS: m/z (% relative intensity) 270
(M+, 1), 78 (2), 71 (29), 70 (4), 64 (2), 59 (5), 58 (100).
16. All of the final structures were confirmed by 1H NMR, 13C NMR, IR, and MS as
the following. Compound 1a: Mp = 99 °C. 1H NMR (CDCl3): d (ppm): 2.27 (s,
6H), 2.69 (dt, J = 5.2 Hz und 1.1 Hz, 2H), 4.52 (t, J = 6.4 Hz, 2H), 6.73 (d,
J = 2.5 Hz, 1H), 7.11 (dd, J = 2.6 Hz und 1.3 Hz, 1H), 7.89 (d, J = 4.9 Hz, 1H), 8.96
(dd, J = 4.9 Hz und 1.9 Hz, 1H), 9.33 (s, 1H). 13C NMR (CDCl3): d (ppm): 45.5,
47.3, 59.4, 108.2, 118.7, 126.2, 129.0, 129.7, 132.6, 139.6, 148.4, 154.9, 174.4,
180.2. IR (KBr): mmax 3102, 2771, 1661, 1586, 1499, 1399, 1247, 1025, 934,
Compound 6b: 1H NMR (CDCl3): d (ppm): 2.06 (m, 2H), 2.28 (s, 6H), 2.38 (t,
J = 6.82 Hz, 2H), 4.55 (t, J = 7.01 Hz, 1H), 6.88 (d, J = 2.52 Hz, 1H), 7.15 (d,
J = 2.76, 1H), 8.94 (s, 2H). 13C NMR (CDCl3): d (ppm): 28.0, 44.8, 47.7, 55.5,
108.9, 129.4, 130.3, 133.0, 145.6, 145.9, 147.4, 147.5, 172.4, 177.7. IR (KBr):
m
max 3420, 2963, 2930, 1667, 1502, 1397, 1254, 1085 cmÀ1. MS: m/z (% relative
intensity) 284 (M+, 2), 215 (3), 212 (5), 120 (3), 85 (8), 84 (81), 72 (6), 59 (5),
58(100).