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Kiyotake Suenaga - One of the best experts on this subject based on the ideXlab platform.

  • Minnamide A, a Linear Lipopeptide from the Marine Cyanobacterium Okeania hirsuta
    2019
    Co-Authors: Shimpei Sumimoto, Osamu Ohno, Arihiro Iwasaki, Shoichiro Suda, Toshiaki Teruya, Masayuki Kobayashi, Rio Sato, Seiichi Shinomiya, Toshiyasu Inuzuka, Kiyotake Suenaga
    Abstract:

    Minnamide A is a lipopeptide with a unique repeating structure consisting of hydroxy and proposed β-branched methyl groups. The absolute configuration of minnamide A was determined by a combination of chemical degradation, Chiral HPLC analyses, and synthetic methods. Minnamide A showed growth-inhibitory activity toward HeLa cells with an IC50 value of 0.17 μM and rapidly induced cell death at a concentration of 2 μM. Minnamide A induced the copper-mediated accumulation of reactive oxygen species

  • croissamide a proline rich cyclic peptide with an n prenylated tryptophan from a marine cyanobacterium symploca sp
    Tetrahedron Letters, 2018
    Co-Authors: Keitaro Iwasaki, Yuki Hitomi, Osamu Ohno, Arihiro Iwasaki, Shimpei Sumimoto, Takuya Sano, Kiyotake Suenaga
    Abstract:

    Abstract Croissamide, a proline-rich cyclic peptide that contains an N-prenylated tryptophan, was isolated from a marine cyanobacterium Symploca sp. Its gross structure was determined by spectroscopic analyses, and the absolute configuration was established based on Chiral HPLC analyses of acid hydrolysates.

  • urumamide a novel chymotrypsin inhibitor with a β amino acid from a marine cyanobacterium okeania sp
    Tetrahedron Letters, 2016
    Co-Authors: Yuki Kanamori, Arihiro Iwasaki, Shinpei Sumimoto, Kiyotake Suenaga
    Abstract:

    Urumamide, a novel cyclic depsipeptide that contains a β-amino acid, was isolated from a marine cyanobacterium Okeania sp. Its gross structure was determined by spectroscopic analyses, and the absolute configuration was established based on Marfey’s analyses and Chiral HPLC analyses of hydrolysis products. Biologically, urumamide inhibited the growth of human cancer cells. In addition, urumamide inhibited chymotrypsin.

  • odoamide a cytotoxic cyclodepsipeptide from the marine cyanobacterium okeania sp
    Tetrahedron, 2016
    Co-Authors: Kiyotake Suenaga, Shinpei Sumimoto, Kosuke Sueyoshi, Masato Kaneda, Shinya Oishi, Nobutaka Fujii, Toshiaki Teruya
    Abstract:

    Abstract The bioassay-guided fractionation of the Okinawan marine cyanobacterium Okeania sp. led to the isolation of the 26-membered cyclodepsipeptide odoamide (1). The gross structure of 1 was determined by 1D and 2D NMR analyses, whereas its absolute stereochemistry was determined using a variety of different methods, including synthesis and chemical degradation followed by Chiral HPLC analysis. Notably, odoamide (1) showed potent cytotoxicity against HeLa S3 human cervical cancer cells with an IC50 value of 26.3 nM.

  • jahanyne an apoptosis inducing lipopeptide from the marine cyanobacterium lyngbya sp
    Organic Letters, 2015
    Co-Authors: Arihiro Iwasaki, Osamu Ohno, Shinpei Sumimoto, Hidetoshi Ogawa, Kim Anh Nguyen, Kiyotake Suenaga
    Abstract:

    An acetylene-containing lipopeptide, jahanyne, was isolated from the marine cyanobacterium Lyngbya sp. Its gross structure was established by spectroscopic analyses, and the absolute configuration was clarified based on a combination of Chiral HPLC analyses, spectroscopic analyses, and derivatization reactions. Jahanyne significantly inhibited the growth of human cancer cells and induced apoptosis in HeLa cells.

Arihiro Iwasaki - One of the best experts on this subject based on the ideXlab platform.

Shinpei Sumimoto - One of the best experts on this subject based on the ideXlab platform.

Osamu Ohno - One of the best experts on this subject based on the ideXlab platform.

Bingui Wang - One of the best experts on this subject based on the ideXlab platform.

  • isolation synthesis and radical scavenging activity of rhodomelin a a ureidobromophenol from the marine red alga rhodomela confervoides
    Organic Letters, 2017
    Co-Authors: Ya Fei Wang, Wei Jia Wang, Sui Qun Yang, James B Gloer, Bingui Wang
    Abstract:

    A novel ureidobromophenol, rhodomelin A (1), was characterized from Rhodomela confervoides. Its structure was elucidated by spectroscopic analysis. Both enantiomers of 1 were synthesized using a convergent strategy starting from d/l-pyroglutamic acids, respectively, allowing assignment of the R-configuration for the naturally occurring isomer by Chiral HPLC analysis. Rhodomelin A represents the first example of a naturally occurring ureidopyrrolidone alkaloid incorporating a γ-aminobutyric acid unit. The scavenging activity of 1 toward DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate)) radicals was assayed.

  • Isolation, Synthesis, and Radical-Scavenging Activity of Rhodomelin A, a Ureidobromophenol from the Marine Red Alga Rhodomela confervoides
    2017
    Co-Authors: Ya Fei Wang, Wei Jia Wang, Sui Qun Yang, James B Gloer, Bingui Wang
    Abstract:

    A novel ureidobromophenol, rhodomelin A (1), was characterized from Rhodomela confervoides. Its structure was elucidated by spectroscopic analysis. Both enantiomers of 1 were synthesized using a convergent strategy starting from d/l-pyroglutamic acids, respectively, allowing assignment of the R-configuration for the naturally occurring isomer by Chiral HPLC analysis. Rhodomelin A represents the first example of a naturally occurring ureidopyrrolidone alkaloid incorporating a γ-aminobutyric acid unit. The scavenging activity of 1 toward DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2′-azinobis­(3-ethylbenzothiazoline-6-sulfonate)) radicals was assayed