Takao Kiyoi

Design, synthesis, and structure–activity relationships of indole-3-carboxamides as novel water soluble cannabinoid CB1 receptor agonists

A novel CB1 receptor agonist lead series was identified using a high-throughput screening approach. The initial screen afforded a single confirmed hit with poor water solubility. Structural variations were explored with the aim of introducing water solubility and improving potency. This led to the discovery of Org 28611, a potent, water soluble CB1 receptor agonist, which was selected for clinical evaluation as a potential intravenous analgesic agent.

Design, synthesis, and structure-activity relationship study of bicyclic piperazine analogs of indole-3-carboxamides as novel cannabinoid CB1 receptor agonists.

Bicyclic piperazine derivatives were synthesized as conformationally constrained analogs of N-alkyl piperazines and were found to be potent CB1 receptor agonists. The CB1 receptor agonist activity was dependent upon the absolute configuration of the chiral center of the bicyclic ring system. Although the conformational constraint did not protect the compounds from metabolism by N-dealkylation, several bicyclic analogs were found to be more potent than the unconstrained lead compound. Compound 8b demonstrated potent antinociceptive activity in vivo.

Low brain penetrant CB1 receptor agonists for the treatment of neuropathic pain.

Novel, low brain penetrant, orally bioavailable CB1 receptor agonists were designed starting from a mature lead series of potent brain penetrant CB1 receptor agonists. Increasing the calculated polar surface area was found to be a good strategy for reducing brain penetration whilst retaining drug-like properties. This in silico approach led to the discovery of LBP1, an orally bioavailable, low brain penetrant CB1 receptor agonist with robust activity in rodent models of neuropathic pain and a good preclinical therapeutic profile, which was selected for clinical development.

Design, synthesis, and structure–activity relationships of indole-3-heterocycles as agonists of the CB1 receptor

Novel indole-3-heterocycles were designed and synthesized and found to be potent CB1 receptor agonists. Starting from a microsomally unstable lead 1, a bioisostere approach replacing a piperazine amide was undertaken. This was found to be a good strategy for improving stability both in vitro and in vivo. This led to the discovery of 24, which had an increased duration of action in the mouse tail flick test in comparison to the lead 1.

ONE-POT SYNTHESIS OF LEWIS X OLIGOSACCHARIDE DERIVATIVES USING ARMED-DISARMED COUPLING METHOD

Abstract A stereocontrolled synthesis of Lex oligosaccharide derivatives using a facile one-pot, two-step glycosylation based on the “Armed-Disarmed” concept are described. The first coupling of phenyl O-(2,6-di-O-benzoyl-3,4-O-isopropylidene-β-D-galacto-pyranosyl)-(1→4)-2,6-di-O-benzoyl-1-thio-β-D-glucopyranoside (2) with phenyl 2,3,4-tri-O-benzyl-1-thio-β-L-fucopyranoside (3) using N-iodosuccinimide (NIS)-trifluoromethanesulfonic acid (TfOH) gave the trisaccharide (8) which was subjected to the second condensation without purification with several acceptors such as ethyl 2,4,6-tri-O-benzyl-β-D-galactopyranoside (4), ethyl 2,6-di-O-benzoyl-β-D-galactopyranoside (5), ethyl O-(2,6-di-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside (6), and ethyl O-(2,6-di-O-benzoyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside (7), to afford the desired Lex tetra- and pentasaccharides in good yields, respectively. 1. Dedicated to the memory of Professor Akira Hasegawa.

Design, synthesis, and structure–activity relationship study of conformationally constrained analogs of indole-3-carboxamides as novel CB1 cannabinoid receptor agonists

Novel tricyclic indole-3-carboxamides were synthesized as structurally restricted analogs of bicyclic indoles, and found to be potent CB1 cannabinoid receptor agonists. The CB1 agonist activity depended on the absolute configuration of the chiral center of the tricyclic ring. The preferred enantiomer was more potent than the structurally unconstrained lead compound. Structure-activity relationships in the amide side chain of the indole C-3 position were also investigated.

Design, synthesis and structure–activity relationships of (indo-3-yl) heterocyclic derivatives as agonists of the CB1 receptor. Discovery of a clinical candidate

We report an expansion of the structure-activity relationship (SAR) of a novel series of indole-3-heterocyclic CB1 receptor agonists. Starting from the potent but poorly soluble lead, 1, a rational approach was taken in order to balance solubility, hERG activity and potency while retaining the desired long duration of action within the mouse tail flick test. This led to the discovery of compound 38 which successfully progressed into clinical development.

Discovery of potent and orally bioavailable heterocycle-based cannabinoid CB1 receptor agonists

Novel 3-(1H-indol-3-yl)-1,2,4-oxadiazoles and -thiadiazoles were synthesized and found to be potent CB1 cannabinoid receptor agonists. The oral bioavailability of these compounds could be dramatically improved by optimization studies of the side chains attached to the indole and oxadiazole cores, leading to identification of a CB1 receptor agonist with good oral activity in a range of preclinical models of antinociception and antihyperalgesia.

A stereoselective α-fucosylation reaction using 1-hydroxy 2,3,4-tri-O-benzyl-l-fucose donor for the practical synthesis of selectin blocker

A 1-hydroxy 2,3,4-tri-O-benzyl-L-fucose donor affords a high stereoselectivity of glycosylation in the presence of TMSOTf and is a very useful substrate for the preparation of an alpha-L-fucosyl dipeptide in a stereoselective manner. The donor will be a key component in the preparation of an attractively biological selectin blocker 1.

Design and Synthesis of Novel Amino-triazine Analogs as Selective Bruton’s Tyrosine Kinase Inhibitors for Treatment of Rheumatoid Arthritis

Brutons tyrosine kinase (BTK) is a promising drug target for the treatment of multiple diseases, such as B-cell malignances, asthma, and rheumatoid arthritis. A series of novel aminotriazines were identified as highly selective inhibitors of BTK by a scaffold-hopping approach. Subsequent SAR studies of this series using two conformationally different BTK proteins, an activated form of BTK and an unactivated form of BTK, led to the discovery of a highly selective BTK inhibitor, 4b. With significant efficacy in models in vivo and good ADME and safety profiles, 4b was advanced into preclinical studies.