Chemical investigation of ethyl acetate bark extracts of Indigofera ammoxylum red and white phenotypes led to the bio-guided isolation of four previously undescribed flavonoids, named (2S,3R)-3',7-dihydroxy-4',6-dimethoxyflavanol (1), (2S,3R)-6-methoxy-7-hydroxyflavanol (2), 2',3',7-trihydroxy-4',6-dimethoxyisoflavone (7) and 2',5' -dimethoxy-4',5,7-trihydroxyisoflavanone (8), along with 14 known compounds (3-6 and 9-18). The previously undescribed structures were characterized based on NMR, HRESIMS, UV and IR data. Published spectroscopic data were used to deduce the structure of the known compounds.
View Article and Find Full Text PDFIsocaloteysmannic acid (), a new chromanone, was isolated from the leaf extract of the medicinal species Willd. along with 13 known metabolites belonging to the families of biflavonoids (), xanthones (-, ), coumarins (-) and triterpenes (, -). The structure of the new compound was characterized based on nuclear magnetic resonance (NMR), high-resolution electrospray mass spectrometry (HRESIMS), ultraviolet (UV) and infrared (IR) data.
View Article and Find Full Text PDF(L.) Jacq from Reunion Island (Indian Ocean) was investigated for its leaf essential oil composition. The plant was extracted by hydrodistillation and its essential oil analysed by gas chromatography coupled to mass spectrometry.
View Article and Find Full Text PDFBioactivity-guided fractionation of the ethyl acetate extract of the leaves of Poupartia borbonica led to the isolation of three new alkyl cyclohexenone derivatives 1-3, and named Poupartone A-C. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data analysis and MS, whereas calculated and experimental ECD spectra were used to define the absolute configurations. These compounds were active against 3D7 and W2 Plasmodium falciparum strains with IC values between 0.
View Article and Find Full Text PDFThe antioxidant properties of trans-aconitic acid (TAA) alone or in the presence of usual antioxidants were assessed by DPPH assay. The IC50 value equal to 70mM was very high compared to usual antioxidants (vitamin C and trolox). A joint experimental/theoretical study suggested that hydrogen atom abstraction in TAA by DPPH was located on -CH2- methylene bridge because the corresponding radical was more stabilized than COO(·) and CC(·) radicals.
View Article and Find Full Text PDFThe rational design of the organic ligand allows to finely tune the degree of delocalization of mixed-valence Prussian blue-like molecules.
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