Flavonol arabinofuranosides from the methanolic extract of Hypericum jovis Greuter.

The genus Hypericum L. (Clusiaceae) is subject of several studies during the last years because of its promising biological activities, since it biosynthesizes a plethora of active compounds, such as napthodianthrones, phloroglucinols, flavonoids, xanthones and phenolic acids [1]. It comprises more than 450 taxa worldwide [2]; 40 taxa in Greece, 12 of them endemic. Apart from the well-studied species H. perforatum, approximately 60% of Hypericum spp. have not been evaluated yet. This is the first study of the methanolic extract from H. jovis, a narrow Greek endemic species. Three flavonoid arabinofuranoses, namely avicularin, 2ʹ’-acetyl-avicularin and 2ʹ’-acetyl-juglanin have been isolated and their structures were elucidated by high-field 1D & 2D NMR. Avicularin is a common metabolite of Hypericum spp., while 2ʹ’-acetyl-avicularin is a rare natural product, which has previously been isolated only twice, namely from Tibouchina semidecandra and Berchemia floribunda [3],[4]. To the best of our knowledge, 2ʹ’-acetyl-juglanin is being described for the first time as a natural product.

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• References

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