Hisaji Taniguchi

FA15, a hydrophobic derivative of ferulic acid, suppresses inflammatory responses and skin tumor promotion: comparison with ferulic acid

In our previous study, FA15 (2-methyl-1-butyl ferulic acid) was chemically synthesized as a novel ferulic acid (FA) analog, and found to notably suppress phorbol ester-induced Epstein-Barr virus activation and superoxide anion generation in vitro. In this report, we demonstrated that FA15, in contrast to FA, markedly suppressed the combined lipopolysaccharide and interferon-gamma-induced protein expressions of inducible nitric oxide synthase and cyclooxygenase-2, and also inhibited the release of tumor necrosis factor-alpha accompanied by suppression of I-kappa B degradation in RAW264.7, a murine macrophage cell line. In ICR mouse skin, topical application of FA15 significantly attenuated phorbol ester-triggered hydrogen peroxide production and edema formation as well as papilloma development while that of FA did not. Our results suggest that FA15, derived from natural sources, is a novel chemopreventive agent, both structurally and functionally.

Synthesis of amide compounds of ferulic acid, and their stimulatory effects on insulin secretion in vitro

We prepared amide compounds which were derived from ferulic acid using various amines, and investigated their stimulatory effects on insulin secretion using rat pancreatic RIN-5F cells. Most of these compounds exhibited significant promotion of the insulin-release at a concentration of 10 microM and in particular, the amides having n-butyl, n-pentyl, pyrrolidine, and piperidine groups showed high activity.

Syntheses of ferulic acid derivatives and their suppressive effects on cyclooxygenase-2 promoter activity

Novel ferulic acid derivatives in which feruloyl groups were attached to the hydroxyl groups of myo-inositol 1,3,5-orthoformate derivatives were synthesized. These feruloyl-myo-inositols suppressed the cyclooxygenase-2 (COX-2) promoter activity in a concentration-dependent manner. Among the examined compounds, compound 9 showed the highest activity. A treatment with 100 microM of compound 9 for 24 h resulted in a 50% decrease of COX-2 promoter activity without marked cytotoxicity. Both the molecular structure in which two ferulic acid moieties are facing each other and the molecular hydrophobicity may be essential for the suppression of COX-2 promoter activity.

Rapid base-catalyzed decarboxylation and amide-forming reaction of substituted cinnamic acids via microwave heating

Decarboxylation of substituted cinnamic acids having a hydroxyl group at the para position gave predominantly the corresponding styrene derivatives in the presence of base with microwave heating. The reaction was conducted either under solvent-free conditions or using a solvent. When a primary amine was used as a base, the yield of the styrene or amide depended on the substituent of the cinnamic acid. Microwave heating for this reaction suppressed the side reactions compared with conventional heating.

Suppressive effects of novel ferulic acid derivatives on cellular responses induced by phorbol ester, and by combined lipopolysaccharide and interferon-γ

A total of 23 ferulic acid (FA) derivatives were synthesized, and investigated for their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus (EBV) activation and superoxide (O(2)(-)) generation. Most of the derivatives showed significant EBV activation suppression or cytotoxicity at a concentration of 100 microM, with FA15 as the most potent suppressor. In both assays, FA6-FA17, bearing straight- or branched-alkyl side chains, exhibited marked suppression of O(2)(-) generation, with both FA16 and FA17 being highly active, while FA itself was virtually inactive. The activity differences seen between FA16/FA17 and FA are attributable, at least in part, to their cellular incorporating efficiencies. Further, both FA15 and FA21 attenuated the expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins, while FA did not. Our results suggest that these novel FA derivatives are effective chemopreventive agents.

A Novel Geranylated Derivative, Ethyl 3-(4′-Geranyloxy-3′-Methoxyphenyl)-2-Propenoate, Synthesized from Ferulic Acid Suppresses Carcinogenesis and Inducible Nitric Oxide Synthase in Rat Tongue

Objectives: We have previously observed the inhibitory effect of ferulic acid on rat tongue carcinogenesis. In this study, we investigated the modifying effects of a novel geranylated derivative, ethyl 3-(4′-geranyloxy-3′-methoxyphenyl)-2-propenoate (EGMP), synthesized from ferulic acid on tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO). Methods: F344 male rats except those treated with EGMP alone and untreated rats were given 20 ppm 4-NQO in drinking water for 9 weeks to induce tongue neoplasms. Starting 1 week after the cessation of exposure to 4-NQO, the experimental groups given 4-NQO and a basal diet were fed the experimental diets containing EGMP (0.2% and 2%) for 20 weeks. The activities of glutathione S-transferase (GST) and quinone reductase (QR), the expression of proliferating cell nuclear antigen, polyamine content and ornithine decarboxylase activity in the tongue were examined for mechanistic analysis of modifying effects of EGMP on carcinogenesis. The expression of inducible nitric acid synthase (iNOS) was also assessed immunohistochemically. Results: At week 30, the incidence and multiplicity of tongue squamous cell carcinoma were significantly reduced by feeding of a 2% EGMP diet. EGMP feeding (2% in diet) elevated tongue GST activity and lowered QR activity in the tongue. Dietary EGMP decreased the expression of cell proliferation biomarker expression. Interestingly, EGMP feeding altered iNOS expression in the invasive parts of carcinoma. Conclusions: These results suggest that EGMP, when given at the 2% dose level during the promotion phase, exerts a chemopreventive action against tongue tumorigenesis through modification of cell proliferation activity and/or detoxifying enzymatic activity.

A Probable Hydrogen-Bonded Meisenheimer Complex: An Unusually High SNAr Reactivity of Nitroaniline Derivatives with Hydroxide Ion in Aqueous Media

Observations show that nitroanilines exhibit an unusually high S(N)Ar reactivity with OH(-) in aqueous media in reactions that produce nitrophenols. S(N)Ar reaction of 4-nitroaniline (2a) in aqueous NaOH for 16 h yields 4-nitrophenol (4a) quantitatively, whereas a similar reaction of 4-nitrochlorobenzene (1a) gave 4a in 2% yield together with recovered 1a in 97%, suggesting that the leaving ability of the NH(2) group far surpasses that of Cl under these conditions. An essential feature of S(N)Ar reactions of nitroanilines is probably that the NH(2) leaving group participates in a hydrogen-bonding interaction with H(2)O. Density functional theory (DFT) calculations for a set of 4-nitroaniline, OH(-), and H(2)O suggest a possible formation of a Meisenheimer complex stabilized by hydrogen-bonding interactions and a six-membered ring structure. The results obtained here contrast with conventional S(N)Ar reactivity profiles in which nitroanilines are nearly unreactive with nucleophiles in organic solvents.

Self-organized honeycomb-patterned microporous polystyrene thin films fabricated by calix[4]arene derivatives.

Calix[4]arene derivatives bearing carboxyl groups at the upper rim and alkyl groups at the lower rim were synthesized. Micrometer-size porous honeycomb-patterned thin films were prepared by evaporating chloroform solution of polystyrene containing the calixarene derivatives under high humidity. These films were coated on gold electrodes of QCM, and the high-frequency changes were observed to detect volatile organic compounds such as dichlorobenzene.

Contrasting intermolecular and intramolecular exciplex formation of a 1,4-dicyano-2-methylnaphthalene-N,N-dimethyl-p-toluidine dyad.

An intramolecular exciplex is formed upon excitation of the cyclohexane solution of the 1,4-dicyano-2-methylnaphthalene-N,N-dimethyl-p-toluidine dyad, but little if any intramolecular CT complex exists in the ground state of this substance in solution. In contrast, in the crystalline state, the dyad forms an intermolecular mixed-stack CT complex in the ground state and an intermolecular exciplex when it is photoexcited.

Synthesis of novel polyphenols consisted of ferulic and gallic acids, and their inhibitory effects on phorbol ester-induced Epstein-Barr virus activation and superoxide generation.

We prepared novel polyphenols which were esters composed of two naturally occurring products, ferulic and gallic acids, and investigated their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus (EBV) activation and superoxide (O2-) generation. Most of these compounds exhibited significant EBV activation suppression at a concentration of 20 microM and in particular, the ester 5f having 2-methyl-1-butyl group showed high activity. The suppressive effects on O2- generation were also observed in most of the esters.