Bioorganic & Medicinal Chemistry Letters 12 (2002) 1135–1137
`
`An Efficient Chemical Synthesis of Nicotinamide Riboside
`(NAR) and Analogues
`
`Shinji Tanimori,* Takeshi Ohta and Mitsunori Kirihata
`
`Department of Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, Osaka Prefecture University,
`1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan
`
`Received 17 December 2001; accepted 22 February 2002
`
`Abstract—A simple and efficient synthesis of nicotinamide riboside (NAR) 1 and derivatives 4 and 5 via trimethylsilyl tri-
`fluoromethanesulfonate (TMSOTf)-mediated N-glycosilation followed by spontaneous deacetylation by treating with methanol is
`reported. # 2002 Elsevier Science Ltd. All rights reserved.
`
`Nicotinamide riboside (NAR) 1 is important as a pre-
`cursor of nicotinamide mononucleotide (b-NMN) 10,
`which is a component for both chemical1 and enzy-
`matic2 preparation of nicotinamide adeninedinucleotide
`(NAD+) 2. The importance of NAD+ and derivatives
`such as NADP+, NADH, and NADPH as coenzymes
`for cellular oxidation and reduction reactions is well
`known.3 In addition, NAD+ has been shown to be the
`precursor to cyclic ADP-ribose (cADPR) 3, a newly
`discovered general mediator involved in Ca2+ signal-
`ing.4 Although there are numerous cADPR analogues
`synthesized previously due to their biological impor-
`tance, to our knowledge, few examples concerning N-1-
`glycosidic derivatives have been reported.5 To obtain
`these compounds, there was need for a reliable, prac-
`tical synthesis of b-NMN and derivatives. Three essen-
`tially different pathways to the preparation of b-NMN
`(i) enzymatic degradation of NAD+,6
`are known:
`(ii) condensation of 1-amino sugars with N1-(2,4-dini-
`trophenyl)-3-aminocarbonylpyridinium halogenides,7
`and (iii) condensation of peracylated halo sugars with
`nicotinamide.8 The biological process is not suitable
`for analogue synthesis. The chemical synthesis using
`halo sugars and/or 1-amino sugars was inefficient due to
`their instability. We describe here a simple and efficient
`synthesis of NAR 1 and its xylose and arabinose
`trifluoro-
`derivatives 4 and 5 using trimethylsilyl
`methanesulfonate (TMSOTf)-mediated N-glycosilation9
`of tetraacetate 6, 7 and 8 followed by spontaneous
`
`*Corresponding author. Tel.: +81-722-54-9469; fax: +81-722-54-
`9918; e-mail: tanimori@biochem.osakafu- u.ac.jp
`
`deacetylation on treatment with methanol as the key
`steps.
`
`The synthesis of NAR started from commercially avail-
`able b-d-ribofuranose 1,2,3,5-tetraacetate 6 (Scheme 1).
`Reaction of 6 with nicotinamide in the presence of
`TMSOTf in acetonitrile at room temperature for 1 h
`followed by the addition of methanol produced N1-(b-
`d-ribofuranosyl)-3-aminocarbamoylpyridinium triflate
`1 via triacetate 9 (not isolated). The N-glycoside 1 thus
`obtained contained up to 13% of the a-anomer as
`determined by 1H NMR spectroscopy. The a-anomer
`was removed by chromatography on activated charcoal
`and crystallization to give b-1 in 58% isolated yield.
`Along the same reaction pathway, the xylose and ara-
`binose derivatives (b-4 and a,b-mixture of 510) were also
`prepared starting from the corresponding tetraacetate 7
`(a/b=33:67) and 8 (a/b=63:37)11 in 67 and 78% yield,
`the a-
`respectively (Scheme 2). In the latter case,
`anomeric isomer was predominantly produced (a/
`b=61:39) due to neighboring group participation and
`the mixture was not separable by chromatography on
`activated charcoal.
`
`Thus, a simple and efficient method for the chemical
`synthesis of NAR and derivatives via TMSOTf-medi-
`ated N-glycosilation followed by spontaneous deacety-
`lation by treating with methanol has been revealed in
`one-pot manner. Synthetic studies of other NAR
`derivatives directed toward the synthesis of NAD+
`analogues for the enzymatic studies of ADP-ribosyl-
`cyclase and NAD glycohydrolase4 are currently under
`investigation.
`
`0960-894X/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
`P I I : S 0 9 6 0 - 8 9 4 X ( 0 2 ) 0 0 1 2 5 - 7
`
`THORNE - EXHIBIT 1014
`
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`1136
`
`S. Tanimori et al. / Bioorg. Med. Chem. Lett. 12 (2002) 1135–1137
`
`Typical Experimental Procedure
`
`Synthesis of 3-(N-D-ribofuranosylcarbamoyl)pyridinium
`triflate (

-1). To a stirred solution of tetraacetate 6 (0.2
`g, 0.63 mmol) and nicotinamide (86 mg, 0.70 mmol) in
`dry acetonitrile (5 mL), TMSOTf (1.0 mL, 5.17 mmol)
`was added dropwise at room temperature and the mix-
`ture was stirred for 1 h at the same temperature.
`Methanol (2.5 mL) was added to the mixture and stirred
`for 30 min, then the solvent was evaporated in vacuo.
`The residue was chromatographed on activated char-
`coal (eluted with H2O to 10% MeOH in H2O) to give a
`
`colorless syrup after removal of the solvent. The syrup
`was dissolved in minimum amount of methanol and
`then ethyl acetate was added to produce b-1 (0.15 g,
`solid. Rf=0.41 (n-BuOH/H2O/
`58%) as a white
`AcOH=5:3:2); IR nmax cm1: 3410, 3101, 2934, 2112,
`1739, 1698, 1639, 1591, 1553, 1411, 1229, 1167, 1100,
`1032, 913, 840, 763, 679, 642, 577, 520; 1H NMR d
`(D2O): 9.23 (1H, s, H-2), 8.96 (1H, d, J=6.1 Hz, H-4),
`8.81 (1H, d, J=7.9 Hz, H-6), 8.06 (1H, dd, J=6.7, 7.6
`Hz, H-5), 5.70 (1H, d, J=8.9 Hz, H-10), 4.13–4.08 (1H,
`m, H-20), 3.96–3.87 (2H, m, H-30, H-40), 3.78 (1H, dd,
`J=12.2, 12.5 Hz, H-50), 3.63 (1H, dd, J=2.6, 9.0 Hz,
`H-50); TOF-MS (DHBA): m/z 255.2 ([MOTf]+).
`
`Scheme 1.
`
`Scheme 2.
`
`

`

`S. Tanimori et al. / Bioorg. Med. Chem. Lett. 12 (2002) 1135–1137
`
`1137
`
`3-(N-D-Xylofuranosylcarbamoyl)pyridinium triflate (

-
`4). Rf=0.32 (n-BuOH/H2O/AcOH=5:3:2); 1H NMR d
`(D2O): 9.33 (1H, s, H-2), 8.99 (1H, d, J=6.1 Hz, H-4),
`8.82 (1H, d, J=8.8 Hz, H-6), 8.10 (1H, dd, J=7.0, 7.3
`Hz, H-5), 5.58 (1H, d, J=8.5 Hz, H-10), 4.12 (1H,
`dd, J=5.4, 11.5 Hz, H-20), 3.64–3.85 (1H, m, H-40),
`3.54–2.95 (3H, m, H-30, H-50); TOF-MS (DHBA): m/z
`254.6 ([MOTf]+).
`
`3-(N-D-Arabinofuranosylcarbamoyl)pyridinium triflate
`(a,b-5).
`Rf=0.38
`(n-BuOH/H2O/
`and
`0.27
`AcOH=5:3:2); 1H NMR d (D2O): 9.33 (0.6H, s, H-2),
`9.22 (0.4H, s, H-2), 9.03–8.97 (1H, m, H-4), 8.83 (0.4H,
`d, J=7.9 Hz, H-6), 8.75 (0.6H, d, J=5.3 Hz, H-6), 8.09
`(0.6H, dd, J=7.0, 7.3 Hz, H-5), 8.00 (0.4H, dd, J=7.3,
`7.3 Hz, H-5), 6.16 (0.4H, d, J=3.1 Hz, H-10), 5.52
`(0.6H, d, J=8.5 Hz, H-10), 4.46 (0.4H, dd, J=5.4, 8.7
`Hz, H-40), 4.32 (0.6H, dd, J=3.4, 4.3 Hz, H-40), 4.13–
`4.05 (1H, m, H-20), 3.88 (0.6H, s, H-30), 3.83 (0.4H, s, H-
`30), 3.79–3.70 (1H, m, H-50), 3.69–3.60 (1H, m, H-50);
`TOF-MS (DHBA): m/z 255.9 ([MOTf]+).
`
`References and Notes
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