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antibacterial activity revealed that biscyclic macrocycle
1 remarkably inhibited all the pathogenic bacteria in
most of the tested concentrations as compared to other
three compounds and control.
13. (a) Rajakumar, P.; Dhanasekaran, M.; Selvam, S.; Ara-
vindan, P. G.; Velumurugan, D. J. Org. Chem. 2005, 70,
3267; (b) Rajakumar, P.; Selvam, S.; Dhanasekaran, M.
Tetrahedron Lett. 2005, 46, 6127; (c) Rajakumar, P.;
Sekar, K.; Srinivasan, K. Tetrahedron Lett. 2005, 46, 1905;
(d) Rajakumar, P.; Srisailas, M. Tetrahedron 2003, 59,
5373; (e) Rajakumar, P.; Srisailas, M. Tetrahedron Lett.
2002, 43, 1909; (f) Rajakumar, P.; Srisailas, M. Tetrahe-
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Tetrahedron 2001, 57, 9749.
In addition, the chiral biscyclic macrocycle 1 was active
against the test pathogens at all three different pH values
of 5–7. Further, compound 1 was also found to be supe-
rior to the commercial antibiotic, tetracycline, in con-
trolling E. coli, P. vulgaris and P. aeruginosa when
tested at pH 7. The minimum inhibitory concentra-
tions18 of compound 1 were between 15 and 25 mM as
compared to 25 and 100 mM for other compounds
and tetracycline. However, its effect against P. mirabilis
was equal to that of tetracycline (Table 1).
30
14. Cyclophane 1. Yield 54%; ½aꢁD ꢀ17.40, (c 0.01, CHCl3);
1
mp 195 ꢁC; H NMR (500 MHz, CDCl3): d 5.00 (d, 4H,
J = 13.0 Hz); 5.12 (t, 8H, J = 15.3 Hz); 5.19 (d, 4H,
J = 13.0 Hz); 6.44 (s, 2H); 6.86 (d, 8H, J = 8.4 Hz); 6.93
(d, 8H, J = 8.4 Hz); 6.97 (d, 2H, J = 10.0 Hz); 7.19–7.23
(m, 8H); 7.25 (s, 4H); 7.27–7.34 (m, 4H); 7.61–7.64 (m,
2H); 7.68–7.71 (m, 2H); 7.85 (d, 4H, J = 8.4 Hz); 7.88 (d,
4H, J = 9.2 Hz); 8.25–8.28 (m, 2H); 9.06 (d, 2H,
J = 9.9 Hz); 13.38 (s, 2H): 13C NMR (125 MHz, CDCl3):
d 69.8, 70.0, 104.8, 109.8, 111.2, 117.0, 120.2, 123.7, 125.4,
126.5, 126.7, 127.2, 128.1, 129.3, 129.5, 133.2, 133.5, 134.1,
134.2, 135.2, 136.0, 137.2, 148.1, 153.8, 159.5, 166.0, 184.3;
m/z (FAB-MS) 1491 (M+). Elemental Anal. Calcd for
In conclusion, the compounds 1, 2, 14 and 17 exhibited
good antibacterial activity against all the four human
pathogenic bacteria. The compound 1 may be developed
as antibiotic drug as it showed superior activity against
all the test pathogens than the other compounds includ-
ing tetracycline. However, further studies are required to
determine their potential against a wide range of human
pathogens and its mode of actions. Synthesis of more
permanent fluorescence sensing chiral macrocycles and
their antibacterial activity as well as molecular recogni-
tion towards chiral guest molecules is on the way.
C100H70N2O12: C, 80.52; H, 4.73; N, 1.88. Found: C,
80.37; H, 4.69; N, 1.78.
30
15. Cyclophane 2. Yield 43%; ½aꢁD ꢀ273.33 (c 0.01, CHCl3);
1
mp 205 ꢁC; H NMR (500 MHz, CDCl3): d 4.93 (d, 4H,
J = 13.0 Hz); 5.11 (d, 4H, J = 13.0 Hz); 4.97 (d, 4H,
J = 13.0 Hz); 5.03 (d, 4H, J = 13.0 Hz); 5.22 (s, 4H); 6.17
(br s, 2H); 6.75–6.77 (m, 14H); 6.86 (d, 8H, J = 7.7 Hz);
7.19– 7.25 (m, 10H); 7.29–7.32 (m, 6H); 7.50 (t, 2H,
J = 8.4 Hz); 7.83–7.85 (m, 6H); 7.88 (d, 4H, J = 9.2 Hz):
13C NMR (125 MHz, CDCl3): d 69.9, 70.9, 101.0, 108.6,
115.3, 119.3, 119.6, 120.2, 120.7, 123.7, 124.8, 125.4, 126.6,
126.7, 128.1, 129.3, 129.4, 133.8, 134.2, 134.9, 136.3, 136.9,
139.2, 153.8, 158.3, 159.6, 182.5, 184.0; m/z (FAB-MS)
1465 (M+). Elemental Anal. Calcd for C100H72O12: C,
81.95; H, 4.95. Found: C, 81.77; H, 4.86.
Acknowledgments
The authors thank CSIR, India, for financial assistance,
SAIF, CDRI, Lucknow, for FAB-MS spectra and Dr.
P. Ramamurthy, NCUFP, University of Madras, for
fluorescence studies. S.S. thanks CSIR for SRF.
30
16. Cyclophane 3 Yield 63%; ½aꢁD ꢀ250.94, (c 0.01, CHCl3);
1
References and notes
mp 265 ꢁC; H NMR (500 MHz, CDCl3): d 4.84–4.93 (m,
12H); 4.98 (d, 4H, J = 13.0 Hz); 5.15 (d, 4H, J = 13.0 Hz);
6.06 (s, 2H); 6.20 (s, 4H); 6.73 (d, 8H, J = 8.0 Hz); 6.89 (d,
8H, J = 8.0 Hz); 7.23–7.27 (m, 12H); 7.31–7.33 (m, 10H);
7.40 (d, 2H, J = 9.2 Hz); 7.84–7.89 (m, 10H); 7.95 (d, 2H,
J = 9.2 Hz): 13C NMR (125 MHz, CDCl3): d 69.8, 69.9,
70.7, 100.9, 108.5, 115.2, 116.0, 120.2, 120.6, 123.7, 123.9,
125.4, 125.7, 126.5, 126.7, 128.1, 129.3, 129.5, 129.6, 134.2,
134.3, 136.4, 136.9, 140.2, 153.8, 154.2, 159.1; m/z (FAB-
MS) 1511 (M+). Elemental Anal. Calcd for C106H78O10: C,
84.22; H, 5.20. Found: C, 84.01; H, 5.29.
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