Two New Phenolic Glycosides from <i>Sorbus commixta</i>

Abstract

From the stem bark of Sorbus commixta, two new phenolic glycosides, sorcomisides A and B (1 and 2), were isolated along with 10 known compounds. The structures of the isolates were determined by analysis of one-dimensional and two-dimensional NMR (1D-and 2D-NMR) data and high resolution (HR)-MS, chemical reaction, and computational methods. All the isolated compounds (1-12) were tested for their neuroprotective, anti-inflammatory, and cytotoxic activities. Key words Sorbus commixta; phenolic glycoside; DP4+Sorbus commixta HEDL. is a deciduous tree belonging to the family Rosacese, and widely distributed throughout Korea and Japan. This plant has been used as a traditional medicine in Korea to treat cough, asthma, bronchial disorder, gastritis, and dropsy.1,2) Although there has been research on the pharmacological activities of S. commixta such as antioxidative, antiatherogenic, anti-inflammatory, anti-sclerotic, and vascular relaxant activities, only a few investigations of the bioactive constituents of this plant have been carried out.3) We previously reported 10 fatty acids and their neuroprotective and anti-inflammatory activities from S. commixta, 4) and herein, further identified 12 compounds including two new phenolic glycosides ( Fig. 1). Their chemical structures were determined through conventional NMR and high resolution (HR)-MS data analysis, computational analysis coupled with advanced statistics, and chemical reaction. All these phytochemicals (1-12) were tested for their neuroprotective, anti-inflammatory, and cytotoxic activities. Results and DiscussionSorcomiside A (1) was purified as a colorless gum and its molecular formula was determined as C 21 102.9, 74.9, 77.9, 71.8, 76.0, and 65.3), a cyanide (δ C 119.3), and an oxygenated carbon (δ C 69.3). These spectroscopic data of 1 (Table 1) were similar to those of 6′-O-galloylsambunigrin and 6′-O-galloylprunasin 5) except for the presence of the signals for a monosubstituted aromatic ring in 1 instead of those for a 3,4,5-trihydroxy aromatic ring in 6′-O-galloylsambunigrin and 6′-O-galloylprunasin. The analysis of two-dimensional NMR (2D-NMR) data including correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond connectivity (HMBC) spectra confirmed the 2D structure of 1 (Fig. 2). The HMBC correlations of H-7/C-1′ and H-6′/C-7″ determined the connections of the β-glucopyranosyl moiety with the phenylacetonitrile group and the benzoic acid, respectively. The absolute configuration of the glucopyranosyl moiety was established through chiral derivatization and LC/MS analysis. 6,7) The retention time of the derivative of 1 (13.6 min) matched that of standard D-glucopyranose (13.6 min), not L-glucopyranose (12.6 min), which confirmed the absolute configuration of the glucopyranose moiety of 1 as D-configuration. To assign the absolute configuration of C-7, we compared the 1 H-NMR data of 1 with those of prunasin and sambunigrin.8) The only structural difference is that these two compounds posse...

Ethnopharmacologically important but underestimated genus Sorbus: a comprehensive review

“…What is noteworthy, not only S. commixta extracts were examined, but also its components. Kim et al (2016Kim et al ( , 2018 and Choi et al (2018) tested several isolates from the bark of S. commixta, including four new structures, namely 1,2,4-trimethoxydibenzofuran-3,9-diol, sorcomic acid, sorcomisides A and sorcomisides B, however these compounds were found to be inactive. Ethanol-water leaf extract from Sorbus umbellata (Desf.)…”

“…), amygdalin (L, BA, W, SE etc. ), sambunigrin (FR)Other compounds 1,2,4-trimethoxydibenzofuran-3,9-diol (BA), bpyrufuran (BA), benzyl b-D-glucopyranoside (FR)Takaishi et al (1977),Kim et al (2016Kim et al ( , 2018, Lee et al (2017) and Choi et al (2018) S. discolor Carboxylic acids Tartaric acid (FR), fumaric acid (FR), malic acid (FR), citric acid (FR) Mikulic-Petkovsek et al (2017) et al (2017) BA bark, FR fruit, L leaf, SE seed, SB stem bark, W wood. * Classified as phenol by the authors.…”

Potential therapeutic properties of Sorbus commixta twig ethanol extract on vitiligo in skin cells

“…In addition, two new phenolic glycosides were isolated from S. commixta, showing that these compounds inhibited the production of proinflammatory molecules. [24][25]. In our further endevours, we will focus on identifying the functional compounds for the treatment of vitiligo in STE, besides the compounds mentioned above.…”