An Efficient Synthesis of 2'-O-(β-D-Ribofuranosyl)biopterin

Abstract

N2-(N,N-Dimethylaminomethylene)-3-[2-(4-nitrophenyl)ethyl]-1',2'-di-O-(trimethylsilyl)biopterin (4) was prepared from biopterin (1a, 86% overall yield) in 5 steps. Glycosylation of 4 with 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose (5a) and its 2,3,5-tri-O-benzoyl analog (5b) respectively afforded the corresponding 2'-O-(2,3,5-tri-Oacetyl- and 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)biopterin derivatives (6a, 42% and 6b, 60%) as major products. Removal of the protecting groups of 6b provided 2'-O-(β-D-ribofuranosyl)biopterin (1c, 87% overall yield) in 3 steps.

First synthesis of asperopterin A, an isoxanthopterin glycoside from Aspergillus oryzae

“…Owing to its low solubility in chloroform, compound 16 was temporarily silylated with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) in the presence of ammonium sulfate in chloroform under reflux for 24 h, yielding the solubilized trimethylsilyl derivative ( 17 ) quantitatively [12,16]. Removal of the protecting groups of isoxanthopterin glycoside ( 19 ) was performed according to well-established procedures [12,16]: treatment of 19 with sodium methoxide in methanol to cleave benzoyl groups and then with aqueous ammonia-methanol to remove the …”

“…Removal of the protecting groups of isoxanthopterin glycoside ( 19 ) was performed according to well-established procedures [12,16]: treatment of 19 with sodium methoxide in methanol to cleave benzoyl groups and then with aqueous ammonia-methanol to remove the …”

Synthesis of biopterin and related pterin glycosides

“…1). For example, 2′‐ O ‐(α‐ D ‐glucopyranosyl)biopterin ( 1b ) and its β‐ D ‐ribofuranosyl analog ( 1c ) were isolated from cyanobacteria (14–18), whereas 2′‐ O ‐(2‐acetamido‐2‐deoxy‐β‐ D ‐glucopyranosyl)biopterin (limipterin) ( 1d ) was obtained from a green sulfur photosynthetic bacterium (19). Similar congeners of other pterins having a hydroxyalkyl side chain at C‐6, such as ciliapterin ( 2a ), neopterin ( 3a ), 6‐hydroxymethylpterin ( 4a ), and 6‐(pentahydroxypentyl)pterin ( 5a ), have also been obtained in certain prokaryotes (20–28).…”

Synthesis of 6-Hydroxymethylpterin α- and β-D-Glucosides

“…Certain pterin glycosides carrying various kinds of sugars attached to the side-chain at C-6 of the pteridine ring were found to be produced by some prokaryotes as exemplified by glycosides of biopterin (1): 2'-O-(α-D-glucopyranosyl)biopterin (2) 1-4 and its β-D-ribofuranosyl analog (3) 5 isolated from various cyanobacteria and 2'-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)biopterin (4) 6 from a green sulfur photosynthetic bacterium. As for glycosides of other pterins, 2-acetamido-2-deoxy-β-D-glucoside of ciliapterin (tepidopterin) 7 and 2-amino-2-deoxy-α-D-glucoside of neopterin (solfapterin) 8 were isolated from a green sulfur photosynthetic bacterium and a thermophilic archaebacterium, respectively, whereas glycosides of 6-hydroxymethylpterin (5a), such as D-glucoside (6) 9,10 and cyanopterin (7), 11 were found in cyanobacterium Synechocysts sp.…”