Satoshi Shuto

Adjacent substituents on a cyclopropane ring mutually exert steric repulsion quite significantly, because they are fixed in eclipsed conformation to each other. Based on this structural feature of the cyclopropane ring, conformationally restricted analogs of milnacipran (1), namely 1-phenyl-2-(1-aminoalkyl)-N,N-diethylcyclopropanecarboxamides (2, 3, ent-2, and ent-3) were designed as potent NMDA receptor antagonists and were synthesized highly enantioselectively. Reaction of (R)-epichlorohydrin

Phospholipase D from Streptomyces effectively catalyzed the transfer reaction of the phosphatidyl residue from 3-sn-phosphatidylcholine to the 5'-hydroxyl group of nuclesides in a two-phase system. Thus, a variety of 5'-(3-sn-phosphatidyl)nucleosides could be readily prepared in high yields by means of this reaction. Among them, phosphatidyl-FUR (3b), phosphatidyl-Ara FC (8b), and phoshatidyl-neplanocin A (12b) each produced a significant increase in the life span mice bearing i.p.-implanted P38

The synthesis of cyclic ADP-carbocyclic-ribose (cADPcR, 4) designed as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca2+-mobilizing second messenger, was achieved using as the key step a condensation reaction with the phenylthiophosphate-type substrate 14 to form an intramolecular pyrophosphate linkage. The N-1-carbocyclic-ribosyladenosine derivative 16 was prepared via the condensation between the imidazole nucleoside derivative 17, prepared from AICA-riboside (19), and the readily availab

Peptidomimetics, non-natural mimicries of bioactive peptides, comprise an important class of drug molecules. The essence of the peptidomimetic design is to mimic the key conformation assumed by the bioactive peptides upon binding to their targets. Regulation of the conformation of peptidomimetics is important not only to enhance target binding affinity and selectivity, but also to confer cell-membrane permeability for targeting protein-protein interactions in cells. The rational design of peptid

(+/-)-(Z)-2-(Aminomethyl)-1-phenylcyclopropane-N,N-diethylcarbo xamide (milnacipran, 1), a clinically useful antidepressant, and its derivatives were prepared by an improved method and were evaluated as NMDA receptor antagonists. Of these, milnacipran (1), its N-methyl and N,N-dimethyl derivatives, 7 and 8, respectively, and its homologue 12 at the aminomethyl moiety had binding affinity for the receptor in vitro (IC50: 1, 6.3 +/- 0.3 microM; 7, 13 +/- 2.1 microM; 8, 88 +/- 1.4 microM; 12, 10 +/

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTOne-Pot Conversion of α,β-Unsaturated Alcohols into the Corresponding Carbon-Elongated Dienes with a Stable Phosphorus Ylide−BaMnO4 System. Synthesis of 6'-Methylene Derivatives of Neplanocin A as Potential Antiviral Nucleosides. New Neplanocin Analogues. 111Satoshi Shuto, Satoshi Niizuma, and Akira MatsudaView Author Information Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan Cite this:

An efficient method for the synthesis of 4'alpha-branched 2'-deoxyadenosines starting from 2'-deoxyadenosine has been developed utilizing a novel radical cyclization reaction with a silicon tether. The radical reaction of 4'beta-(phenylseleno)-3'-O-diphenylvinylsilyl adeninenucleoside derivative 17 with Bu(3)SnH and AIBN, followed by Tamao oxidation, gave selectively either the 4'alpha-(2-hydroxyethyl) derivative 21 or 4'alpha-(1-hydroxyethyl) derivative 19, depending on the reaction conditions.

3,7-Anhydro-D-glycero-D-ido-octitol 1,5,6-trisphosphate (5) was designed as a novel IP(3)-receptor ligand having a C-glycosidic structure and was synthesized via a radical cyclization reaction with a temporary connecting vinylsilyl tether as the key step. The phenyl 2-O-dimethylvinylsilyl-3,4, 6-tri-O-benzyl-1-seleno-beta-D-glucopyranoside (7), in the usual (4)C(1)-conformation, was successively treated with Bu(3)SnH/AIBN and under Tamao oxidation conditions to give a mixture of five C-glycosidi

The development of potent proteasome inhibitors based on the stereochemical diversity-oriented strategy using a conformationally rigid cyclopropane structure was investigated. Thus, a series of stereo- and regioisomeric analogs of belactosin A (2), a cyclopropane amino acid (methanoamino acid)-containing tripeptidic proteasome inhibitor, were designed, in which the central cyclopropane amino acid part was replaced with the corresponding stereo- or regioisomer. Using a series of stereoisomeric cy

Abstract We have developed a one‐pot ring‐closing metathesis (RCM)/oxidation methodology to yield various 2‐quinolines from 2‐vinyl‐ N ‐allylaniline derivatives. This is a first example of an oxidation involving methylene (CH 2 ) groups with modified Grubbs‐type ruthenium complexes. Hence, this adds an example of a non‐methathesis reaction using a ruthenium carbene catalyst.

Conformationally restricted analogues of (+/-)-(Z)-2-aminomethyl-1-phenyl-N,N-diethylcyclopropanecarboxamide++ + [milnacipran, (+/-)-1] were designed on the basis of its characteristic cyclopropane structure and were synthesized enantioselectively to develop efficient NMDA receptor antagonists. Among these analogues, (1S,2R)-1-phenyl-2-[(R)-1-amino-2-propynyl]-N, N-diethylcyclopropanecarboxamide (2d) had one of the most potent affinities for the receptor, with a Ki value of 0.29 microM. The bloc

Cyclic ADP-ribose (cADPR), a general mediator involved in Ca2+ signaling, has the characteristic 18-membered ring consisting of an adenine, two riboses and a pyrophosphate, in which the two primary hydroxyl groups of the riboses are linked by a pyrophosphate unit. This review focuses on the chemical synthetic studies of cADPR analogs. These analogs have been used quite effectively in proving the mechanism of cADPR-mediated Ca2+ signaling pathways. These analogs are also expected to be lead struc