N.B. Kalamkar et al. / Tetrahedron 66 (2010) 8522e8526
8525
25
36.10; H, 7.07; Rf 0.3 (CH2Cl2/MeOH/25% NH4OH¼2/7/1); [
a
]
buffer (pH 9.8) and absorbance of the liberated p-nitrophenol was
measured at 405 nm with a UVevisible Spectrophotometer. Con-
trols were run simultaneously in the absence of test compound.
One unit of glycosidase activity is defined as the amount of enzyme
D
ꢀ12.6 (c 1.3, MeOH) [lit.13f
[a
]
26 ꢀ15.0 (c 1, H2O)].
D
4.1.5. 5,6-Dideoxy-6-(N-benzyl,N-benzyloxycarbonyl)amino-1,2-O-
isopropylidene- -gluco-1,4-furanose (5b). Reaction of 3b (1.7 g,
a-
D
that hydrolyzed 1 m
mol of p-nitrophenol per minute at 37 ꢁC. The
8.5 mmol) in dry CH2Cl2 (90 mL) with 1 M solution of DIBAL-H in
toluene (9.33 mL, 9.35 mmol) as stated for 4a furnished lactol 4b
(1.66 g, 97% crude yield) as a sticky solid. Reaction of 4b (1.2 g
5.94 mmol) with benzyl amine (0.71 mL, 6.53 mmol), sodium cya-
noborohydride (0.92 g, 14.8 mmol) and glacial acetic acid (0.05 mL
0.9 mmol) in dry methanol (2 mL) followed by reaction with benzyl
chloroformate in toluene (2.98 mL 17.81 mmol) and aq NaHCO3
(2.5 g, 29.7 mmol, 8 mL water) as described for 5a and column
chromatography using n-hexane/ethyl acetate¼4/1 yielded 5b
(2.43 g, 92% in two steps) as a colorless thick liquid. Found: C, 67.21;
inhibition constants (Ki) and the nature of the inhibition were de-
termined from LineweavereBurk plots.
Acknowledgements
We are grateful to Prof. M.S. Wadia for helpful discussions. We
are thankful to the University of Pune for financial support (BCUD/
OSD/184-2009). N.B.K. and V.M.K. are thankful to the CSIR, New
Delhi, for Senior Research Fellowships.
H, 7.12. C24H29NO6 requires:C, 67.43; H, 6.84; Rf 0.56 (n-hexane/ethyl
Supplementary data
25
acetate¼1/1); [
a]
ꢀ2.3 (c 2.54, CHCl3); IR (CH2Cl2) 3443 (broad),
D
1693,1220,1076 cmꢀ1; 1H NMR (300 MHz, CDCl3)
d 1.29 (3H, s, CH3),
Copies of 1H and 13C NMR spectra of 5a, 5b, 1c, 1c$HCl, 1d,
1d$HCl and LineweavereBurk plots of 1d against glycosidase.
Supplementary data associated with this article can be found in
MOL files and InChIKeys of the most important compounds de-
scribed in this article.
1.45 (3H, s, CH3), 1.54e2.0 (2H, m, H-5), 3.10e3.40 (2H, m, H-6),
3.80e4.20 (3H, m, H-3, H-4, OH), 4.38e4.6 (3H, m, NeCH2Ph, H-2),
5.20 (2H, s, O-CH2Ph), 5.82 (1H, d, J¼3.57, 1-H), 7.10e7.40 (10H, m,
AreH); 13C NMR (75 MHz, CDCl3)
d 26.0 (CH3), 26.5 (CH3), 43.5 (C-5),
44.0 (C-6) 50.7 (NeCH2Ph), 67.3 (O-CH2Ph) 74.9 (C-4), 78.0 (C-3),
85.1 (C-2), 104.2 (C-1), 111.1 (isopropylidene), 127.3, 127.7, 127.9,
128.3, 128.4, 136.2, 137.3 (Ar), 156.4 (NCOO).21
References and notes
4.1.6. 1,5,6-Trideoxy-1,6-imino- -xylo-hexitol (1d). Reaction of 5b
D
1. (a) Woynaroska, B.; Wilkiel, H.; Sharma, M.; Carpenter, N.; Fleet, G. W. J.; Ber-
nacki, R. J. Anticancer Res. 1992, 12, 161; (b) Gross, P. E.; Baker, M. A.; Carver, J. P.;
Dennis, J. W. Clin. Cancer Res. 1995, 1, 935.
2. (a) Johnston, P. S.; Coniff, R. F.; Hoogwerf, B. J.; Santiago, J. V.; Pi-Sunyer, F. X.;
Krol, A. Diabetes Care 1994, 17, 20; (b) Kleist, P.;Ehrlich, A.;Suzuki,Y.;Timmer, W.;
Wetzelsberger, N.; Luecker, P. W.; Fuder, H. Eur. J. Clin. Pharmacol. 1997, 53, 149.
3. (a) Alper, J. Science 2001, 291, 2338; (b) Stone, D. L.; Tayebi, N.; Orvisky, E. Hum.
Mutat. 2000, 15, 181.
4. (a) Robina, I.; Moreno-Vargas, A. J.; Carmona, A. T.; Vogel, P. Curr. Drug Metab.
2004, 5, 329; (b) Fleet, G. W. J.; Karpas, A.; Dwek, R. A.; Fellows, L. E.; Tyms, A.
S.; Petursson, S.; Namgoong, S. K.; Ramsden, N. G.; Smith, P. W.; Son, J. C.;
Wilson, F.; Witty, D. R.; Jacobs, G. S.; Rademacher, T. W. FEBS Lett. 1988, 237, 128.
5. (a) Stutz, A. E. Iminosugars as Glycosidase Inhibitors: Nojirimycin and Beyond, 1st
ed.; Wiley: Weinheim, Germany, 1999; (b) Iminosugars: From Synthesis to
Therapeutic Applications; Compain, P., Martin, O. R., Eds.; John Wiley: Chi-
chester, UK, 2007; (c) Paulsen, H. Angew. Chem., Int. Ed. Engl. 1966, 5, 495; (d)
Look, G. C.; Fotsch, C. H.; Wong, C.-H. Acc. Chem. Res. 1993, 26, 182; (e) Ganem, B.
Acc. Chem. Res. 1996, 29, 340; (f) de Melo, E. B.; Gomes, A. d. S.; Carvalho, I.
Tetrahedron 2006, 62, 10277; (g) Pandey, G.; Dumbre, S. G.; Khan, M. I.; Shabab,
M. J. Org. Chem. 2006, 71, 8481; (h) Davis, B. G. Tetrahedron: Asymmetry 2009,
20, 652.
(0.61 g, 1.42 mmol) with TFA/H2O (3:2, 12 mL) followed by hydro-
genation with 10% Pd(OH)2/C (0.08 g) in aq methanol (10 mL, 9:1)
as described for 1c and column chromatography purification using
CH2Cl2/MeOH/25% NH4OH 3/2/0.2 afforded 1d (178 mg, 85%) as
a sticky solid: Rf 0.4 (CH2Cl2/MeOH/25% NH4OH¼3/6/1); [
a]
25 18.1
D
(c 0.95, MeOH) [lit.14a 26 16.36 (c 0.33, MeOH)].
[a]
D
4.1.7. 1,5,6-Trideoxy-1,6-imino-D-xylo-hexitol, hydrochloride salt
(1d$HCl). Compound 1d (40 mg, 0.27 mmol) in methanol (3 mL)
was reacted with concentrated HCl (0.3 mL) as described for 1c$HCl
to afford hydrochloride salt 1d$HCl (49 mg, 99%) as a yellow
gummy solid. Found: C, 39.53; H, 7.91. C6H14ClNO3 requires C,
22
39.24; H, 7.68; Rf 0.3 (CH2Cl2/MeOH/25% NH4OH¼2/6/1); [
a
]
D
4.0
(c 2.4, H2O). IR (KBr) 3331e2833 (broad), 1579, 1053 cmꢀ1; 1H NMR
(300 MHz, D2O) 2.12e2.25 (2H, m, H-5), 3.16e3.30 (1H, m, H-6),
d
3.32e3.58 (3H, m, H-1/H-6), 3.68 (1H, dd, J¼7.2 and 5.2 Hz, H-3),
6. Paulsen, H.; Todt, K. Chem. Ber. 1967, 100, 512.
7. (a) Simmott, M. L. Chem. Rev. 1990, 90, 1171; (b) Winchester, B.; Fleet, G. W. J. Gly-
cobiology 1992, 2, 199; (c) Bols, M. Acc. Chem. Res.1998, 31, 1; (d) Heightman, T. D.;
Vasella, A. T. Angew. Chem., Int. Ed. 1999, 38, 750; (e) Zechel, D. L.; Withers, S. G.
Acc. Chem. Res. 2000, 33,11;(f)Lillelund,V. H.;Jensen,H.H.;Liang,X.;Bols, M.Chem.
Rev. 2002, 102, 515; (g) Asano, N. Curr. Top. Med. Chem. 2003, 3, 471.
3.84 (1H, dt, J¼7.2 and 3.6 Hz, H-4), 4.10 (1H, dt, J¼5.2 and 2.3 Hz, H-
2); 13C NMR (75 MHz, D2O)
(C-4), 72.5 (C-2), 78.4 (C-3).
d 27.6 (C-5), 42.2 (C-6), 45.3 (C-1) 68.2
8. (a) Kim, Y. J.; Ichikawa, M.; Ichikawa, Y. J. Am. Chem. Soc.1999,121, 5829; (b) Sears,
P.; Wong, C.-H. Angew. Chem., Int. Ed.1999, 38, 2301; (c) Saotome, C.; Wong, C.-H.;
Kanie, O. Chem. Biol. 2001, 8, 1061; (d) Pandey, G.; Kapur, M. Org. Lett. 2002, 4,
3883; (e) Compain, P.; Martin, O. R. Curr. Top. Med. Chem. 2003, 3, 541.
9. Qian, X.-H.; Moris-Varas, F.; Wong, C.-H. Bioorg. Med. Chem. Lett. 1996, 6, 1117.
10. Our results are well in agreement with that reported see: Moris-Varas, F.; Qian,
X.-H.; Wong, C.-H. J. Am. Chem. Soc. 1996, 118, 7647.
11. Johnson, H. A.; Thomas, N. R. Bioorg. Med. Chem. Lett. 2002, 12, 237.
12. For trihydroxy azepane 1d and stereoisomers see: (a) Shih, T.-L.; Yang, R.-Y.; Li,
S.-T.; Chiang, C.-F.; Lin, C.-H. J. Org. Chem. 2007, 72, 4258; (b) Moutel, S.; Shipman,
M.; Martin, O. R.; Ikeda, K.; Asano, N. Tetrahedron: Asymmetry 2005, 16, 487; (c)
Andersen, S. M.; Ekhart, C.; Lundt, I.; Stutz, A. E. Carbohydr. Res. 2000, 326, 22; (d)
Gallos, J. K.; Demeroudi, S. C.; Stathopoulou, C. C.; Dellios, C. C. Tetrahedron Lett.
2001, 42, 7497;(e) See Ref. 6. This paperdoes notdescribe the synthesis of the free
azepane base but the protected version: N-Ac, tri-O-Ac derivative.
13. For tetrahydroxy azepane 1c and stereoisomers see: (a) Ref. 10. (b) Painter, G. F.;
Eldridge, P. J.; Falshaw, A. Bioorg. Med. Chem. 2004, 12, 225; (c) Painter, G. F.;
Falshaw, A.; Wong, H. Org. Biomol. Chem. 2004, 2, 1007; (d) Andreana, P. R.;
Sanders, T.; Janczuk, A.; Warrick, J. I.; Wang, P. G. Tetrahedron Lett. 2002, 43,
6525; (e) Fuentes, J.; Gasch, C.; Olano, D.; Pradera, M. A.; Repetto, G.; Sayago, F.
J. Tetrahedron: Asymmetry 2002, 13, 1743; (f) Joseph, C. C.; Regeling, H.; Zwa-
nenburg, B.; Chittenden, G. J. F. Tetrahedron 2002, 58, 6907; (g) Painter, G. F.;
Falshaw, A. J. Chem. Soc., Perkin Trans. 1 2000, 1157; (h) Dax, R.; Gaigg, B.;
Grassberger, B.; Koelblinger, B.; Stutz, A. E. J. Carbohydr. Chem. 1990, 9, 479; (i)
Fuentes, J.; Gasch, C.; Olano, D.; Pradera, M. A. Tetrahedron Lett. 1999, 40, 4063;
4.2. Procedure for the inhibition assay
The enzymes
mannosidase, and N-acetyl-
from almond seeds; -galactosidase was isolated from G. toebii BK1
and -glucosidase was procured from Sigma Chemical Co. were
a
-galactosidase,
b
-galactosidase,
b-glucosidase, a-
b-D-glucosaminidase were isolated
a
a
used for glycosidase inhibitory activity. Inhibition potencies of 1c
and 1d were determined by measuring the residual hydrolytic
activities of the glycosidases. The substrates p-nitrophenyl-
copyranoside, p-nitrophenyl- -glucopyranoside, p-nitrophenyl-
-galactopyranoside and p-nitrophenyl- -galactopyranoside,
p-nitrophenyl-N-acetyl- -glucopyranoside, and p-nitrophenyl-
-mannopyranoside (all of Sigma Chemicals Co., USA) of 2 mM
b-D-glu-
a-D
a
-D
b-D
b-
D
a-
D
concentration, were prepared in 0.025 M citrate buffer with pH 4.0
and used for assay. The test compound (of various concentrations
from 20
buffered at its optimal pH, for 1 h at 37 ꢁC. The enzyme reaction was
initiated by the addition of 100 L of substrate. Reaction was ter-
minated at the end of 90 min by the addition of 0.05 M borate
mM to 1000 mM) was pre-incubated with the enzyme,
m