- 著者
- 横田 正 大嶽 徹朗 鈴木 里英 衛藤 英男 大嶋 俊二 稲熊 隆博 石黒 幸雄
- 出版者
- 天然有機化合物討論会実行委員会
- 雑誌
- 天然有機化合物討論会講演要旨集 45 (ISSN:24331856)
- 巻号頁・発行日
- pp.449-454, 2003-09-01 (Released:2017-08-18)
Lycopene has aroused public interest owing to its role in preventing oxidative damage, cancer and aging, etc. These activities are considered to be due to its high ability of scavenging active oxygen species. In the present work, we have examined the products formed by the photosensitized oxygenation, hydrogen peroxide oxidation, m-chloroperbenzoic acid (mCPBA) oxidation and peroxinitrite oxidation of lycopene. We also isolated two oxygenated lycopenes with a novel five-membered ring end-group from tomato puree. In photosensitized oxygenation (singlet oxygen oxidation), we isolated apo-6'-lycopenal and 6-methyl-5-hepten-2-one. The reaction is supposed to proceed via 1,2 addition of singlet oxygen to 5,6 double bond of lycopene. In hydrogen peroxide and m CPBA oxidation, we isolated oxygenated lycopenes with a novel five-membered ring end-group (2,6-cyclolycopene-1,5-diol, 2,6-cyclolycopene-1,5-epoxide, 1,16-didehydro-2,6-cyclolycopene-5-ol and 1-methoxy-2,6-cyclolycopene-5-ol). It is proposed that the formation for these compounds occurs by rearrangement of lycopene 5,6-epoxide. In peroxinirite oxidation, we could classify the products into three types, 1) oxidative cleavage products, 2) non-cleavage oxidative products that have C40 carbon skeleton, and 3) Z-isomers of lycopene. The reaction pathways to form these compounds will be discussed.
- 著者
- 吉村 誠司 善光 龍哉 大津 嘉弘 金崎 竜一 重松 伸治 高瀬 茂弘 閨 正博
- 出版者
- 天然有機化合物討論会実行委員会
- 雑誌
- 天然有機化合物討論会講演要旨集 45 (ISSN:24331856)
- 巻号頁・発行日
- pp.281-286, 2003-09-01 (Released:2017-08-18)
During the course of seeking for novel gluconeogenesis inhibitors, FR225659 and its four congeners were isolated from the fermentation broth of Helicomyces sp. No.19353. Series of NMR analysis allowed elucidation of their planar structures. The planar structure of FR225659 includes a novel acyl moiety, an unprecedented amino acid residue, 3-chloro-4-hydroxyarginine, and two unique amino acid residues, a 3-hydroxy-3-methylproline and a dehydrovaline. As all efforts to obtain crystals of 1 suitable for X-ray crystallography turned out to be in vain, a combination of chemical modification and spectroscopic methods was applied to elucidate the stereochemistry of 1. Acid hydrolysis followed by derivatization with chiral phthalic acid allowed X-ray crystallographic analysis of the proline analogue, which determined its stereochemistry to be (2S, 3R). Conformational analysis of 9 using ^<2,3>J_<CH> developed by Murata et. al. allowed assignment of the relative stereochemistry of the arginine analogue to be 2,3-erythro-3,4-threo. Then, the modified Mosher's method suggested that the absolute configuration of 4'-C is R, which was supported by NOE analysis of 1. The CD spectrum of 1 showed positive Cotton effect at 236nm, indicating an optical activity around the biphenyl axis between the quinoline and the phenol of 1. As the CD spectrum lacking clear Davydov split does not appear to be easy to translate, further elucidation of the axial chirality is now in progress. FR225659 family exerted potent inhibitory activities against glucagon-induced gluconeogenesis of rat primary liver cells, while they showed ten or more times less potent cytotoxicities against EL-4 cell line. As they do not suppress gluconeogenesis independent of glucagon, they should stop a signal pathway from glucagon. Diabetes patients are reported to produce more hepatic glucose than normal, and this leads to complications unless properly treated. Thus, FR225659 family can be drug candidates for diabetes to down-regulate the high blood glucose level of those patients. It is noteworthy that the hydroxyl group at position 3" plays important roles in both biological activities and solubility in various solvents.