- Isolation and Total Synthesis of Mabuniamide, a Lipopeptide from an Okeania sp. Marine Cyanobacterium
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The bioassay-guided fractionation of an Okeania sp. marine cyanobacterium collected in Okinawa led to the isolation of the lipopeptide mabuniamide (1). The gross structure of 1 was determined by spectroscopic analyses, and its absolute configuration was determined using Marfey's analysis of the acid hydrolysate of 1. The absolute configuration of 1 was confirmed by total synthesis. Mabuniamide (1) stimulated glucose uptake in cultured rat L6 myotubes. In addition, mabuniamide (1) and its stereoisomer (2) exhibited moderate antimalarial activity.
- Ozaki, Kaori,Iwasaki, Arihiro,Sezawa, Dai,Fujimura, Haruka,Nozaki, Tomoyoshi,Saito-Nakano, Yumiko,Suenaga, Kiyotake,Teruya, Toshiaki
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p. 2907 - 2915
(2019/10/16)
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- Discovery of Amantamide, a Selective CXCR7 Agonist from Marine Cyanobacteria
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CXCR7 plays an emerging role in several physiological processes. A linear peptide, amantamide (1), was isolated from marine cyanobacteria, and the structure was determined by NMR and mass spectrometry. The total synthesis was achieved by solid-phase method. After screening two biological target libraries, 1 was identified as a selective CXCR7 agonist. The selective activation of CXCR7 by 1 could provide the basis for developing CXCR7-targeted therapeutics and deciphering the role of CXCR7 in different diseases.
- Liang, Xiao,Luo, Danmeng,Yan, Jia-Lei,Rezaei, Mohammad A.,Salvador-Reyes, Lilibeth A.,Gunasekera, Sarath P.,Li, Chenglong,Ye, Tao,Paul, Valerie J.,Luesch, Hendrik
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supporting information
p. 1622 - 1626
(2019/03/07)
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- Dudawalamides A-D, Antiparasitic Cyclic Depsipeptides from the Marine Cyanobacterium Moorea producens
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A family of 2,2-dimethyl-3-hydroxy-7-octynoic acid (Dhoya)-containing cyclic depsipeptides, named dudawalamides A-D (1-4), was isolated from a Papua New Guinean field collection of the cyanobacterium Moorea producens using bioassay-guided and spectroscopic approaches. The planar structures of dudawalamides A-D were determined by a combination of 1D and 2D NMR experiments and MS analysis, whereas the absolute configurations were determined by X-ray crystallography, modified Marfey's analysis, chiral-phase GCMS, and chiral-phase HPLC. Dudawalamides A-D possess a broad spectrum of antiparasitic activity with minimal mammalian cell cytotoxicity. Comparative analysis of the Dhoya-containing class of lipopeptides reveals intriguing structure-activity relationship features of these NRPS-PKS-derived metabolites and their derivatives.
- Almaliti, Jehad,Malloy, Karla L.,Glukhov, Evgenia,Spadafora, Carmenza,Gutiérrez, Marcelino,Gerwick, William H.
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p. 1827 - 1836
(2017/06/28)
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- Ohmyungsamycins A and B: Cytotoxic and antimicrobial cyclic peptides produced by Streptomyces sp. from a volcanic island
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Ohmyungsamycins A and B (1 and 2), which are new cyclic peptides, were isolated from a marine bacterial strain belonging to the Streptomyces genus collected from a sand beach on Jeju, a volcanic island in the Republic of Korea. Based on the interpretation of the NMR, UV, and IR spectroscopic and MS data, the planar structures of 1 and 2 were elucidated as cyclic depsipeptides bearing unusual amino acid units, including N-methyl-4-methoxytrytophan, β-hydroxyphenylalanine, and N,N-dimethylvaline. The absolute configurations of the α-carbons of the amino acid residues were determined using the advanced Marfey's method. The configurations of the additional stereogenic centers at the β-carbons of the threonine, N-methylthreonine, and β-hydroxyphenylalanine units were assigned by GITC (2,3,4,6-tetra-O-acetyl- β-d-glucopyranosyl isothiocyanate) derivatization and the modified Mosher's method. We have developed a new method utilizing PGME (phenylglycine methyl ester) derivatization coupled with chromatographic analysis to determine the absolute configuration of N,N-dimethylvaline. Our first successful establishment of the absolute configuration of N,N-dimethylvaline using PGME will provide a general and convenient analytical method for determining the absolute configurations of amino acids with fully substituted amine groups. Ohmyungsamycins A and B showed significant inhibitory activities against diverse cancer cells as well as antibacterial effects.
- Um, Soohyun,Choi, Tae Joon,Kim, Heegyu,Kim, Byung Yong,Kim, Seong-Hwan,Lee, Sang Kook,Oh, Ki-Bong,Shin, Jongheon,Oh, Dong-Chan
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p. 12321 - 12329
(2014/01/17)
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- Two new 14-membered cyclopeptide alkaloids from Zizyphus xylopyra
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The phytochemical investigation of the bark of Zizyphus xylopyra resulted in the isolation of two new 14-membered ring cyclopeptide alkaloids, xylopyrine-G and xylopyrine H. Their structures have been established by chemical and spectral evidences.
- Pandey, Manoj B.,Singh, Sarita,Malhotra, Meenakshi,Pandey, Vidya B.,Singh, Tryambak D.
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experimental part
p. 836 - 841
(2012/10/07)
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