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Saccharin is one of the most common artificial sweeteners that has a bitter taste at high concentrations. Currently, there are no detailed functional analyses of these gustatory receptors. Therefore, we designed and synthesized photoreactive saccharin derivatives that contain a (trifluoromethyl) diazirinyl moiety at the 5- or 6-position for use as functional analysis tools for photoaffinity labeling.

In this paper we report here a hydrogen/deuterium exchange (H/D exchange) of cross-linkable alpha-amino acid derivatives with deuterated trifluoromethanesulfonic acid (TfOD). H/D exchange with TfOD was easily applied to o-catechol containing phenylalanine (DOPA) within an hour. A partial H/D exchange was observed for trifluoromethyldiazirinyl (TFMD) phenylalanine derivatives. N-Acetyl-protected natural aromatic alpha-amino acids (Tyr and Trp) were more effective in H/D exchange than unprotected ones. The N-acetylated TFMD phenylalanine derivative afforded slightly higher H/D exchange than unprotected derivatives. An effective post-deuteration method for cross-linkable alpha-amino acid derivatives will be useful for the analysis of biological functions of bioactive peptides and proteins by mass spectrometry.

Novel hydrogen/deuterium exchange for aromatic α-amino acids and their corresponding peptides were performed through the use of deuterated trifluoromethanesulfonic acid (TfOD). Detailed analysis of the exchange revealed that equal hydrogen/deuterium exchange was observed for phenylalanine, and specific exchange at the ortho-positions of phenol for tyrosine was also detected. The stereochemistry of the aromatic α-amino acids was retained under the exchange conditions. The hydrogen/deuterium exchange properties for these aromatic α-amino acids are identical for peptides that contain several aromatic α-amino acids. The exchange proceeded significantly faster than previous methods. Detailed analysis of the exchange revealed that the method could be controlled by temperature, time, and the amount of reagent.

2-Phenylethylamine is well known as a substructure of many biologically active compounds, and the synthesis of its photoreactive derivatives to allow the analysis of biological functions is reported. This allowed us to synthesise ligands for adenosine receptors, which have many functional roles in biology and have been extensively studied for their many roles in maintaining homeostasis. Adenosine is one of the most common biochemical compounds, but photoaffinity labeling has not yet been used to study adenosine receptors. Synthetic methods for producing photoreactive adenosine derivatives that can be used with adenosine receptors were established for the photophores phenyl azide and benzophenone. The effect of the introduction of the photoreactive components was determined using an adenosine receptor assay.

application/pdf, Based on the recent development of molecular biology, the investigation of biofunctional machinery at their ligand accepting interface has become one of the challenging and important subject of post-genome field. The technique of photoaffinity labeling has become increasingly appreciated as a powerful methodology for the purpose. This micro review focused synthesis of trifluoromethylphenyldiazirine, which is one of the most promising photophore, and its application to the biomolecules.

The anti-allergic activity of Perilla glycopeptide (Pe-GP) isolated from dried Perilla frutescens BRH-TON leaves was investigated. Pe-GP was found to be effective in inhibiting histamine release from IgE-sensitized rat peritoneal mast cells induced by a specific antigen. The histamine release induced by several substances such as concanavalin A, compound 48/80, mastoparan, and ionophore A23187, was also found to be inhibited by Pe-OP. These results suggest that Pe-GP mainly interrupts a pathway of histamine release after calcium influx. Anti-allergic activity of Pe-GP was investigated by ear-swelling response in mice that had been passively sensitized with IgE via intravenous injection. Pe-GP, injected intraperitoneally before exposure to the antigen, was found to inhibit the allergic response in a dosedependent manner (5-100 mg/kg). Pe-GP shows promise as an anti-allergic substance for medical use as well as in health foods. シソ(Perilla frutescens B_)葉熱水抽出液から分離精製されたシソ糖ペプチド(Pe-GP,6kDa)の抗アレルギー活性を検討した。Pe-GPは,ラット腹腔内より単離してIgEで感作したマスト細胞において,特異抗原で刺激したときに誘発されるヒスタミン遊離反応を抑制した。同様にPe-GPはconcanavalin A,compound48/80,mastoparan,ionophore A23187などの誘発するヒスタミン遊離反応も抑制した。これらの結果からPe-GPはヒスタミン遊離機構のうちカルシウム動員以降の経路を主として抑えると考えられる。Pe-GPの生体内における抗アレルギー活性は,IgEを静注して受動感作したマウスの耳介浮腫反応により検討した。抗原塗布前にあらかじめ腹腔内に投与しておくと,Pe-GPは5-100mg/mlの範囲で濃度依存的に浮腫を抑制し抗アレルギー活性を示した。Pe-GPの抗アレルギー活性を有する医薬品としての開発が,健康食品と同様,期待される。

Elucidation of protein functions on the basis of structure–activity relationships can reveal the mechanisms of homeostasis functions in life and is one of the greatest interests of scientists. In the human body, many proteins are activated and/or inactivated by ligands to maintain homeostasis. Understanding the mechanism of molecular interactions between small bioactive ligands and proteins is an important step in rational drug design and discovery. ! Photoaffinity labeling, which is one of the most familiar approaches for chemical biology analysis, was initiated using diazocarbonyl derivatives in 1962 (Singh et al., 1962). Many researchers have subsequently tried to establish alternative approaches for the direct identification of target proteins for the bioactive small ligands. These approaches are based on the affinity between the ligand and the target protein (Figure 1). Several reviews are published for the recent applications of photoaffinity labeling (Tomohiro et al., 2005; Hashimoto & Hatanaka, 2008). To archive photoaffinity labeling, researchers have to prepare photoaffinity labeling ligands. The native ligands must be modified by photoreactive compounds (photophores) by organic synthesis

application/pdf, We have developed two novel 3-phenyl-3-trifluoromethyldiazirinyl bis-glucose derivatives to investigate the properties of the adipocyte glucose transporter GLUT4. These compounds were substituted by electron-with-drawing (iodo and nitro) groups on the aromatic ring of 3-phenyl-3-tritluoromethyldiazirine photophore and were found to be more photosensitive than compounds without such substituents. The compounds were used as inhibitors of insulin-stimulated glucose transport activity in order to assess half-maximal inhibition or relative affinity values for GLUT4. The affinities were found to be 60-130 times higher than the parent compound D-glu-cose. Because of the increased photo-reactivity and high affinity these compounds will be useful in studies directed at further elucidation of GLUT4 function., 日本薬学会Chemical & pharmaceutical bulletin 50(7) p.1004-1006より転載