1.Prolyl endopeptidase inhibitors from the underground part of Rhodiola sacra S. H. Fu.
Fan W;Tezuka Y;Komatsu K;Namba T;Kadota S Biol Pharm Bull. 1999 Feb;22(2):157-61.
Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme which plays a role in the metabolism of proline-containing neuropeptides, e.g., vasopressin, substance P and thyrotropin-releasing hormone (TRH), which have been suggested to be involved in learning and memory processes. In our systematic screening for PEP inhibitors from traditional Chinese medicines, we found that MeOH extract from the underground part of Rhodiola sacra S. H. Fu shows significant inhibitory activity against PEP from Flavobacterium meningosepticum. Examination of the constituents of the extract resulted in the isolation of nineteen known compounds, identified as hydroquinone (1), 4-hydroxybenzoic acid (2), caffeic acid (3), 4-hydroxycinnamic acid (4), suberic acid (5), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 2-phenylethyl beta-D-glucopyranoside (9), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), 2-phenylethyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (11), sacranoside A (12), beta-D-glucopyranosyl 4-hydroxybenzoate (13), rhodiocyanoside A (14), rhodiooctanoside (15), sarmentosin (16), heterodendrin (17), arbutin (18) and 4-O-(beta-D-glucopyranosyl)-gallic acid (19).
2.Hepatoprotective effects of Sedum sarmentosum on D-galactosamine/lipopolysaccharide-induced murine fulminant hepatic failure.
Lian LH;Jin X;Wu YL;Cai XF;Lee JJ;Nan JX J Pharmacol Sci. 2010;114(2):147-57. Epub 2010 Sep 11.
The hepatoprotective effects of sarmentosin-containing extracts of Sedum sarmentosum (SS) in D-galactosamine (D-GalN) / lipopolysaccharide (LPS)-induced fulminant hepatic failure mouse model. Pretreatment with SS markedly protected mice from lethal liver injury, which has known to be associated with an abrupt elevation of serum tumor necrosis factor (TNF)-α level. Indeed, SS significantly blocked the elevation of TNF-α and alanine aminotransferase and aspartate aminotransferase as well. SS also remarkably reduced number of apoptotic hepatocytes and DNA fragmentation in the liver, which correlated with blockade of caspase-3 activation. In addition, SS suppressed the increased expression of toll-like receptor 4 (TLR4). The activation of c-Jun NH(2)-terminal kinase, extracellular signal-regulated kinase, and p38 induced by D-GalN/LPS was also significantly suppressed by SS treatment. Furthermore, SS significantly inhibited the activation of nuclear factor-κB.
3.Diversification of an ancient theme: hydroxynitrile glucosides.
Bjarnholt N;Rook F;Motawia MS;Cornett C;Jørgensen C;Olsen CE;Jaroszewski JW;Bak S;Møller BL Phytochemistry. 2008 May;69(7):1507-16. doi: 10.1016/j.phytochem.2008.01.022. Epub 2008 Mar 14.
Many plants produce cyanogenic glucosides as part of their chemical defense. They are alpha-hydroxynitrile glucosides, which release toxic hydrogen cyanide (HCN) upon cleavage by endogenous plant beta-glucosidases. In addition to cyanogenic glucosides, several plant species produce beta- and gamma-hydroxynitrile glucosides. These do not release HCN upon hydrolysis by beta-glucosidases and little is known about their biosynthesis and biological significance. We have isolated three beta-hydroxynitrile glucosides, namely (2Z)-2-(beta-D-glucopyranosyloxy)but-2-enenitrile and (2R,3R)- and (2R,3S)-2-methyl-3-(beta-D-glucopyranosyloxy)butanenitrile, from leaves of Ribesuva-crispa. These compounds have not been identified previously. We show that in several species of the genera Ribes, Rhodiola and Lotus, these beta-hydroxynitrile glucosides co-occur with the L-isoleucine-derived hydroxynitrile glucosides, lotaustralin (alpha-hydroxynitrile glucoside), rhodiocyanosides A (gamma-hydroxynitrile glucoside) and D (beta-hydroxynitrile glucoside) and in some cases with sarmentosin (a hydroxylated rhodiocyanoside A).