scholarly journals The First Total Synthesis of (±)-Linderol A, a Tricyclic Hexahydrodibenzofuran Constituent ofLindera umbellataBark, with Potent Inhibitory Activity on Melanin Biosynthesis of Cultured B-16 Melanoma Cells

2001 ◽  
Vol 3 (9) ◽  
pp. 1359-1362 ◽  
Author(s):  
Masayuki Yamashita ◽  
Nobukazu Ohta ◽  
Ikuo Kawasaki ◽  
Shunsaku Ohta
Keyword(s):  
Total Synthesis ◽  
Inhibitory Activity ◽  
Melanoma Cells ◽  
Melanin Biosynthesis ◽  
Potent Inhibitory Activity

The effect of chlorophorin and its derivative on melanin biosynthesis

Holzforschung ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 514-518 ◽  
Author(s):  
Enos Tangke Arung ◽  
Keisuke Yoshikawa ◽  
Kuniyoshi Shimizu ◽  
Ryuichiro Kondo
Keyword(s):  
Inhibitory Activity ◽  
Melanoma Cells ◽  
B16 Melanoma ◽  
Mushroom Tyrosinase ◽  
Tyrosinase Inhibitor ◽  
Melanin Biosynthesis ◽  
B16 Melanoma Cells ◽  
Bioassay Guided Fractionation ◽  
Unstable Compound ◽  
Potent Inhibitory Activity

Abstract By means of bioassay-guided fractionation using mushroom tyrosinase, a geranylated stilbene, chlorophorin, was characterized as the principal tyrosinase inhibitor in the heartwood of Chlorophora excelsa (Moraceae). It inhibited the oxidation of L-tyrosine and DL-3,4-dihydroxyphenylalanine (DL-DOPA) due to mushroom tyrosinase and melanin biosynthesis on B16 melanoma cells. Chlorophorin, which is a slight yellowish compound, has previously been reported as an unstable compound in light. On the basis of this finding, a chlorophorin derivative [4-(3″,7″-dimethyloctyl)-2′,3,4′,5-tetrahydroxydihydrostilbene; hexahydrochlorophorin] which is colorless, obtained by the hydrogenation of chlorophorin with Pd/C, was also tested to develop a superior material for practical use. Hexahydrochlorophorin showed more potent inhibitory activity on tyrosinase and melanin biosynthesis, and lower cytotoxicity towards B16 melanoma cells than chlorophorin.

Total synthesis of melleumins A and B and their analogs: Determination of stereochemistry and Wnt signal inhibitory activity

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
M Ishibashi ◽  
S Hanazawa ◽  
Y Uchino ◽  
X Li ◽  
MA Arai
Keyword(s):  
Total Synthesis ◽  
Inhibitory Activity ◽  
Wnt Signal

Total Synthesis of (+)-Granatumine A and Related Bislactone Limonoid Alkaloids via a Pyran to Pyridine Interconversion

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Alexander Schuppe ◽  
Yizhou Zhao ◽  
Yannan Liu
Keyword(s):  
Total Synthesis ◽  
Inhibitory Activity ◽  
Knoevenagel Condensation ◽  
Cost Effective ◽  
Effective Procedure ◽  
Direct Transformation ◽  
Structural Revision ◽  
Alpha Beta ◽  
Ptp 1B

We report the first total synthesis of (+)-granatumine A, a limonoid alkaloid with PTP-1B inhibitory activity, in 10 steps. Over the course of this study, two key methodological advances were made: a cost effective procedure for ketone alpha,beta-dehydrogenation using allyl-Pd catalysis, and a Pd-catalyzed protocol to convert epoxyketones to 1,3-diketones. The central tetrasubstituted pyridine is formed by a convergent Knoevenagel condensation and carbonyl-selective electrocyclization cascade, which was followed by a direct transformation of a 2<i>H</i>-pyran to a pyridine. These studies have led to the structural revision of two members of this family.

scholarly journals Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T

2020 ◽  
Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross
Keyword(s):  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Liquid Culture ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Negative Bacterium ◽  
Gram Negative ◽  
The Absolute ◽  
Potent Inhibitory Activity ◽  
Cyclic Tetrapeptide

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

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