New Isolinariins C, D and E, Flavonoid Glycosides from <i>Linaria japonica</i>

Abstract

Three new flavonoid glycosides named isolinariins C, D and E (1-3), two known flavonoid glycosides (4, 5) and three known flavonoids (6-8) were isolated from the whole plant of Linaria japonica. The structures of these compounds were determined mainly by spectroscopic analyses. The bioactivities of these isolated compounds were evaluated for their inhibitory activities against human cell line A549, collagenase, and advanced glycation end product (AGE) formation. Among the isolated compounds, isolinariins C, D and E (1, 2 and 3) showed inhibition toward AGE formation (IC 50 values of 34.8, 35.0 and 19.5 µM, respectively). And linariin (4), pectolinarin (5) and luteolin (8) were found to be active against collagenase with IC 50 values of 79.4, 78.6 and 40.5 µM, respectively, without significant cytotoxicity at these concentrations.Key words Linaria japonica; cytotoxicity; collagenase; advanced glycation end product; flavonoid glycoside Linaria japonica MIQ. (Scrophulariaceae) is a perennial herb with elliptic and fleshy leaves. The whole plant extract is used as a Japanese folk medicine due to its diuretic, purgative and laxative properties.1) On our reinvestigation of the same plant, collected in sandy seashore areas of Tottori Prefecture, flavonoids, phenylethanoids, iridoids and monoterpene glucosides have been isolated so far.2) On further investigation of the non-polar fraction, i.e. a mixture of hexane and ethyl acetate layers of the same plant, five new diterpenoids were isolated.3) The present study on the same non-polar fraction has demonstrated the presence of three new flavonoid glycosides (1-3) along with linariin (4), pectolinarin (5), pectolinarigenin (6), apigenin (7) and luteolin (8) (Fig. 1) through the isolation by various chromatographic techniques such as silica gel, octadecylsilyl (ODS) and HPLC. The chemical structures of these compounds were determined mainly by spectrometric analyses such as UV, IR, high resolution electrospray ionization (HR-ESI)-MS, one and two dimensional (1 and 2D)-NMR. We also report here the inhibitory activity for collagenase and advanced glycation end products (AGEs) formation of the isolated compounds along with the cytotoxicity against human cell line.

Potency of bisresorcinol from Heliciopsis terminalis on skin aging: in vitro bioactivities and molecular interactions

“…The recent anti-collagenase assay was modified from that previously described by Widyowati et al (2016) . In brief, 50 mmol L −1 tricine buffer pH 7.5 supplemented with 400 mmol L −1 NaCl and 10 mmol L −1 CaCl 2 was used as the buffering diluent.…”