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ABSTRACT: Among thirteen strains of the genus Bacillus isolated from Shrimp-jeotkal in our laboratory, a strain BA34 showing good antifungal activity against Phytophthora infestans in a previous experiment was tested for the inhibitory effect against Akt, protein kinase B. Since Akt is known to play an important role in controlling apoptosis, its inhibitors can be used as potential apoptosis-inducing agents in the treatment of cancer. Two active compounds were isolated and their structures were determined. They have similar structures, despite showing different inhibitory effects. In order to elucidate the reasons for these different effects, three-dimensional studies were carried out.
Journal of Microbiology and Biotechnology 05/2008; 18(4):682-5. · 1.38 Impact Factor
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ABSTRACT: Diosmetin, 5,7,3'-trihydroxy-4'-methoxyflavone shows chemopreventive, antimutagenic, and antiallergic effects. On the other hand, chrysoeriol, 5,7,4'-trihydroxy-3'-methoxyflavone induced nodABC-lacZ in Rhizobium meliloti. Both of them belong to hydroxymethoxy- flavones. One major difference between diosmetin and chrysoeriol is the substituted position of hydroxyl and methoxyl groups. In order to elucidate the relationships between their structures and activity, one of the first things to be done is the determination of their structures. However, most flavones occur widely in nature, and thus it is difficult to obtain in sufficient amounts from natural sources to identify their structures. Assignments of NMR data of several hydroxymethoxyflavones may help us to identify novel flavonoid compounds isolated from natural sources based on their NMR experiments. Therefore, we report here the complete assignments of 1H and 13C NMR data of 13 hydroxymethoxyflavones.
Magnetic Resonance in Chemistry 01/2008; 45(12):1072-5. · 1.44 Impact Factor
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ABSTRACT: Many hydroxyflavone derivatives have been found in nature and shown to have many biological functions. Because their function is changed by the position and number of hydroxyl group, their structural identification is a fundamental and necessary step for understanding their functions. In the present study, the complete 1H and 13C NMR spectral assignments were presented for 6 hydroxyflavones, and NMR data of additional 14 hydroxyflavone derivatives were compared with those of the 6 hydroxyflavones. In addition, the partially incorrect NMR data of two of the dihydroxyflavones whose NMR data were previously reported were corrected.
Magnetic Resonance in Chemistry 09/2007; 45(8):674-9. · 1.44 Impact Factor
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ABSTRACT: Common substitution positions of flavonols are at C-5 and C-7; 6-substituted flavonol derivatives are rarely found in natural sources. Here, we report complete assignments of 1H and 13C chemical shifts of eight flavonol derivatives including four 6-substituted flavonols.
Magnetic Resonance in Chemistry 03/2006; 44(2):188-90. · 1.44 Impact Factor
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ABSTRACT: Six flavone derivatives were studied. Previously reported NMR data of three of these derivatives were corrected and the NMR data for the other three derivatives not studied previously were completely assigned on the basis of the basic 1D and 2D NMR experiments and molecular modeling.
Magnetic Resonance in Chemistry 02/2006; 44(1):99-101. · 1.44 Impact Factor
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ABSTRACT: Nine flavonol derivatives were studied. Previously reported NMR data of three of these derivatives were corrected. We report complete assignments of the NMR data for six flavonol derivatives not previously studied.
Magnetic Resonance in Chemistry 11/2005; 43(10):858-60. · 1.44 Impact Factor
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ABSTRACT: Six flavone derivatives were studied. Previously reported NMR data of three of these derivatives were corrected and the NMR data for the other three derivatives not studied previously were completely assigned on the basis of the basic 1D and 2D NMR experiments and molecular modeling. Copyright © 2005 John Wiley & Sons, Ltd.
Magnetic Resonance in Chemistry 10/2005; 44(1):99 - 101. · 1.44 Impact Factor
