Masanori Tobe

Discovery of quinazolines as a novel structural class of potent inhibitors of NF-κB activation

We disclose here a new structural class of low-molecular-weight inhibitors of NF-kappa B activation that were designed and synthesized by starting from quinazoline derivative 6a. Structure-activity relationship (SAR) studies based on 6a elucidated the structural requirements essential for the inhibitory activity toward NF-kappa B transcriptional activation, and led to the identification of the 6-amino-4-phenethylaminoquinazoline skeleton as the basic framework. In this series of compounds, 11q, containing the 4-phenoxyphenethyl moiety at the C(4)-position, showed strong inhibitory effects on both NF-kappa B transcriptional activation and TNF-alpha production. Furthermore, 11q exhibited an anti-inflammatory effect on carrageenin-induced paw edema in rats.

A novel structural class of potent inhibitors of NF-κB activation: structure–activity relationships and biological effects of 6-aminoquinazoline derivatives

In this study, we have investigated the roles of substituents on the terminal phenyl ring at the C(4)-position of the quinazoline core to complete the structure-activity relationships (SARs) of our NF-kappa B activation inhibitors. Among them, compound 12j afforded highly potent inhibitory activity toward NF-kappa B transcriptional activation with IC(50) value of 2 nM, along with an excellent in vivo efficacy by reducing the edema formation seen in carrageenin-induced inflammation of the rat hind paw.

Synthesis and structure-activity relationships of 2-substituted-8-hydroxyadenine derivatives as orally available interferon inducers without emetic side effects.

Recently we reported the adenine derivatives (2-4) as new interferon (IFN) inducers. In the present study, we conducted a detailed structure and activity relationship study of 4 and its related derivatives on IFN inducing activity. From this study, we found that compound 4 exhibited the most potent IFN inducing activity in vitro with a minimum effective concentration of 0.01 microM, and 4 also showed strong IFN-inducing activity at doses of more than 0.3mg/kg by oral administration in mice. This potency was 10-fold stronger than that of Imiquimod. Moreover, 4 did not cause emesis in ferrets even at doses as high as 10mg/kg, whereas, 80% of animals were emetic when orally administered with the same dose of Imiquimod. These results indicate that compound 4 is superior to Imiquimod with respect to efficacy and safety.

Synthesis and biological evaluation of CX-659S and its related compounds for their inhibitory effects on the delayed-type hypersensitivity reaction.

In order to find novel nonsteroidal compounds possessing an inhibitory activity against delayed-type hypersensitivity (DTH) reactions, we conducted random screening using a picryl chloride (PC)-induced contact hypersensitivity reaction (CHR) in mice, and found compound 1 as a lead compound. Then we synthesized and evaluated an extensive series of 5-carboxamidouracil derivatives focused on both the uracil and the antioxidative moieties. Among them, we found that the hindered phenol moiety was necessary to exhibit the activities; especially, compounds 28a-28c having the partial structure of vitamin E were found to exert potent activities against the DTH reaction by both oral and topical administration. And compound 28c showed antioxidative activity against lipid peroxidation with an IC50 of 5.9 microM. Compound 28c (CX-659S) was chosen as a candidate drug for the treatment of cutaneous disorders such as atopic dermatitis and allergic contact dermatitis.

The chemistry and biological activity of heterocycle-fused quinolinone derivatives: A review

Among all heterocycles, the heterocycle-fused quinolinone scaffold is one of the privileged structures in drug discovery as heterocycle-fused quinolinone derivatives exhibit various biological activities allowing them to act as anti-inflammatory, anticancer, antidiabetic, and antipsychotic agents. This wide spectrum of biological activity has attracted a great deal of attention in the field of medicinal chemistry. In this review, we provide a comprehensive description of the biological and pharmacological properties of various heterocycle-fused quinolinone scaffolds and discuss the synthetic methods of some of their derivatives.

Structure–Activity relationships of 6-fluoroquinazolines: dual-Acting compounds with inhibitory activities toward both TNF-α production and T cell proliferation

Abstract We synthesized various 6-fluoro-7-(1-piperazino)quinazolines based on the structure of 1 and evaluated their inhibitory activities toward both TNF-α production and T cell proliferation responses. Among these compounds, 7a , having the 3,4-(methylenedioxy)phenyl moiety at the C(4)-position of the quinazoline ring, showed both inhibitory activities. Furthermore, the oral treatment with 7a exhibited an anti-inflammatory effect in rats with adjuvant arthritis as well as an inhibitory activity toward LPS-induced TNF-α production.

Synthesis and SAR study of imidazoquinolines as a novel structural class of microsomal prostaglandin E2 synthase-1 inhibitors

The imidazoquinoline derivative 1 was found as a novel mPGES-1 inhibitor. Optimization of 1 led to the identification of the 2-chlorophenyl group at the C(2)-position and the quinolone structure at the C(4)-position. Compound 33, the most potent synthesized compound, showed excellent mPGES-1 inhibition (IC(50)=9.1nM) with high selectivity (>1000-fold) over both COX-1 and COX-2.

Synthesis and structure―activity relationships of phenothiazine carboxylic acids having pyrimidine-dione as novel histamine H1 antagonists

A series of phenothiazine carboxylic acid derivatives, having 6-amino-pyrimidine-2,4(1H,3H)-dione moiety via a appropriate linker, were synthesized and evaluated for their affinity toward human histamine H(1) receptor and Caco-2 cell permeability. Selected compounds were further evaluated for their oral anti-histaminic activity in mice and bioavailability in rats. Finally, promising compounds were examined for their anti-inflammatory potential in mice OVA-induced biphasic cutaneous reaction model. Among the compounds tested, phenothiazineacetic acid compound 27 showed both histamine H(1)-receptor antagonistic activity and anti-inflammatory activity in vivo model.

Regioselective protection of the 2′-hydroxyl group of N-acyl-3′,5′-O-di(t-butyl)silanediylnucleoside derivatives by use of t-BuMgCl and 2-(trimethylsilyl)ethoxymethyl chloride

Abstract Regioselective 2′-O-protection of N-protected 3′,5′-O-di(t-butyl)silanediylribonucleoside derivatives with the 2-(trimethylsilyl)ethoxymethyl (SEM) group has been achieved by use of t-BuMgCl and 2-(trimethylsilyl)ethoxymethyl chloride. The former was used as a base. The 2′-O-SEM protected ribonucleoside derivatives were converted via a three-step reaction into the corresponding phosphoramidite building blocks in good overall yields.

Structure–activity relationships of quinazoline derivatives: dual-acting compounds with inhibitory activities toward both TNF-α production and T Cell proliferation

We synthesized 4-chlorophenethylaminoquinazoline derivatives and evaluated their inhibitory activities toward both TNF-α production and T cell proliferation responses. Compound 2f, containing a piperazine ring at the C(7)-position of the quinazoline ring, exhibited more potent inhibitory activities toward both than the lead compound 1a. A smaller N-substituent in the piperazine ring was required for inhibition of TNF-α production.