Title
Dioic acid glycosides, tannins and methylated ellagic acid glycosides from Morella salicifolia bark
Author
Edna E. Makule, Birgit Kraus, Guido Jürgenliemk, Jörg Heilmann, Stefan Wiesneth
Year
2018
Journal
Phytochemistry Letters
Abstract
The bark of Morella salicifolia (Hochst.exA. Rich.) Verdc. &Polhill (Myricaceae) is a common herbal drug and especially utilized by the Maasai community of northeastern Tanzania. It is traditionally used to treat swellings on the cheek and face, cough, toothache, stomach problems, headaches, and skin diseases. Unless, there is still a lack of information considering the specialized metabolites that may be responsible for the traditional use of this medicinal plant. An isolation study on a methanolic extract revealed three methylated ellagic acids, castalagin, two monomeric flavan-3-ols, three prodelphinidins and three dioic acid glycosides. Among these metabolites, myriside (3,4-dimethyl ellagic acid 4′-O-β-d-xylopyranoside, 1), epigallocatechin-3-O-gallate-(2β→O→7, 4β→8)-gallocatechin (9), 2,7-dimethyl-8-O-(6′-O-galloyl)-β-d-glucopyranoside-deca-2E,4E-dienedioic acid (10), 2,7-dimethyl-8-O-β-d-glucopyranoside-deca-2E,4E-dienedioic acid (11) as well as 4,9-dimethyl-10-O-β-d-glucopyranoside-dodeca-2E,4E,6E-trienedioic acid (12) were isolated for the first time. To the best of our knowledge, the dioic acid glycosides represent a generally novel structure type. To provide comprehensive information on the condensed tannins, the polymeric proanthocyanidins were enriched and characterized via 13C-NMR. Results confirm chemo-taxonomic relationships within the genera Morella and Myrica in the Myricaceae.
Instrument
J-710
Keywords
Circular dichroism, Stereochemistry, Cotton effect, Absolute configuration, Pharmaceutical