Browsing by Author "Sunghwa, Fortunatus"

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    Iodine-Catalyzed Etherification of Morroniside
    (2009-09) Sunghwa, Fortunatus; Sakurai, Hiroaki; Saiki, Ikuo; Koketsu, Mamoru
    In this study, we describe a highly selective etherification procedure of unprotected morroniside catalyzed by molecular iodine in acetone. The etherification reaction furnished 7-O-alkyl ether derivatives in reasonable yields within few hours under neutral conditions. Studies of the obtained products on cytotoxicity activity in colon 26-L5 cell line were examined. Among the tested compounds, 7-O-dodecylmorroniside showed moderate cytotoxic activity, having IC50 values equal to 20.9 μM.
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    Morroniside cinnamic acid conjugate as an anti-inflammatory agent
    (2010-08) Takeda, Yoshinori; Tanigawa, Naomi; Sunghwa, Fortunatus; Ninomiya, Masayuki; Hagiwara, Makoto; Matsushita, Kenji; Koketsu, Mamoru
    A morroniside cinnamic acid conjugate was prepared and evaluated on E-selectin mediated cell-cell adhesion as an important role in inflammatory processes. 7-O-Cinnamoylmorroniside exhibited excellent anti-inflammatory activity (IC(50)=49.3 microM) by inhibiting the expression of E-selectin; further, it was more active than another cinnamic-acid-conjugated iridoid glycoside (harpagoside; IC(50)=88.2 microM), 7-O-methylmorroniside, and morroniside itself. As a result, 7-O-cinnamoylmorroniside was observed to be a potent inhibitor of TNF-alpha-induced E-selectin expression.
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    Phenolic and bis-iridoid glycosides from Strychnos cocculoides
    (2009-10) Sunghwa, Fortunatus; Koketsu, Mamoru
    A new bis-iridoid glucoside, cocculoside (1), has been isolated, together with five known compounds from Strychnos cocculoides (Loganiaceae), collected in Tanzania. The structure of cocculoside (1) has been determined as an ester dimer of loganin and secologanin dimethyl acetal between C-7 and C-11
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    Synthesis and Reactions of Some Derivatives Of (3,6 S,9 R,10 R,11 S)-1,4,7-Trioxaspiro[5,5]Undecane-3,9,10,11-Tetrol: Novel Quasi-Saccharides 1 Presented at the 2nd International Meeting of the Portuguese Carbohydrate Chemistry Group, Porto, Portugal, 21–25 September 1997. 1
    (1998-10) Regeling, Henk; Sunghwa, Fortunatus; Zwanenburg, Binne; de Gelder, Rene; Chittenden, Gordon J. F.
    The title compound was obtained by reductive ozonolysis of allyl β-d-fructopyranoside. The synthesis and characterization of a number of C-3-substituted derivatives using conventional carbohydrate procedures is described. Some of the products may be of biological interest as carbohydrate mimics. The structures of two of the basic products (8 and 9) were substantiated by X-ray diffraction studies. Do you want to read the rest of this article?Access full-text