Isolation, Characterization and In Silico Studies of Secondary Metabolites from the Whole Plant of Polygala inexpectata Peşmen & Erik

Abstract

Polygala species are frequently used worldwide in the treatment of various diseases, such as inflammatory and autoimmune disorders as well as metabolic and neurodegenerative diseases, due to the large number of secondary metabolites they contain. The present study was performed on Polygala inexpectata, which is a narrow endemic species for the flora of Turkey, and resulted in the isolation of nine known compounds, 6,3′-disinapoyl-sucrose (1), 6-O-sinapoyl,3′-O-trimethoxy-cinnamoyl-sucrose (tenuifoliside C) (2), 3′-O-(O-methyl-feruloyl)-sucrose (3), 3′-O-(sinapoyl)-sucrose (4), 3′-O-trimethoxy-cinnamoyl-sucrose (glomeratose) (5), 3′-O-feruloyl-sucrose (sibiricose A5) (6), sinapyl alcohol 4-O-glucoside (syringin or eleutheroside B) (7), liriodendrin (8), and 7,4′-di-O-methylquercetin-3-O-β-rutinoside (ombuin 3-O-rutinoside or ombuoside) (9). The structures of the compounds were determined by the spectroscopic methods including 1D-NMR (1H NMR, 13C NMR, DEPT-135), 2D-NMR (COSY, NOESY, HSQC, HMBC), and HRMS. The isolated compounds were shown in an in silico setting to be accommodated well within the inhibitor-binding pockets of myeloperoxidase and inducible nitric oxide synthase and anchored mainly through hydrogen-bonding interactions and π-effects. It is therefore plausible to suggest that the previously established anti-inflammatory properties of some Polygala-derived phytochemicals may be due, in part, to the modulation of pro-inflammatory enzyme activities.

Xanthones and Xanthone O‐β‐D‐Glucosides from the Roots of Polygala azizsancarii Dönmez

“…The aqueous extract of P. tenuifolia is rich in metabolites, which suggests that it could be a promising source for future anti‐inflammation research [13] . Our previous study on the phenolic compounds and similar sucrose esters isolated from the whole plant material of P. inexpectata have supported this deduction [14] …”

“…[13] Our previous study on the phenolic compounds and similar sucrose esters isolated from the whole plant material of P. inexpectata have supported this deduction. [14] Not only P. tenuifolia and P. senega, but many other Polygala species are used for similar purposes in different regions of the World, such as P. acicularis, P. alpestris, P. altomontana, P. amarella, P. arenaria, P. arillata, P. bakeriana, P. boliviensis, P. caudata, P. chinensis, P. crotalarioides, P. cyparissias, P. dalmaisiana, P. fallax, P. flavescens, P. floribunda, P. glomerata, P. hongkongensis, P. japonica, P. molluginifolia, P. paniculata, P. reinii, P. sabulosa, P. sibirica, P. stenopetale, P. telephioides, P. tricornis, P. vulgaris, and P. wattersii. Secondary metabolites isolated from these Polygala species represent a rich structural diversity and include oleanane-type triterpenoid saponins, sucrose esters, oligosaccharide multi esters, lignans, flavonoids, benzophenones, strylpyrones, coumarins, and xanthones, which are responsible for various functional properties.…”

The Antinociceptive Effect of a Hydroalcoholic Extract of Polygala altomontana and Its Chemical Profile Using UPLC‐ESI‐QTOF‐HR‐MS

“…Nineteen of the 20 detected compounds were identified as aylpropanoid glycosides ( 1 , 2 , 8 , and 10 ), quercetin glycosides ( 3 – 7 ), quercetin glycoside aylpropanoid ester ( 9 ), coumarins ( 11 and 20 ), and styryl‐pyrone derivatives ( 12 – 18 ). Arylpropanoids glycosides including disinapoylsucrose, and sinapoyl sucrose were recently identified in P. inexpectata and P. Tenuifolia [32,33] . Compounds 2 and 10 , identified as sinapoyl glycoside derivatives, have never been reported in the literature.…”

“…Arylpropanoids glycosides including disinapoylsucrose, and sinapoyl sucrose were recently identified in P. inexpectata and P. Tenuifolia. [32,33] Compounds 2 and 10, identified as sinapoyl glycoside derivatives, have never been reported in the literature. Apart from isoquercitrin obtained from P. elongate, [34] other quercetin glycosides have never been identified in Polygala species.…”