The corrected structure of depressoside,an antioxidative iridoid glucoside extracted from the flowers of Gentiana urnula Harry Sm.

Three known iridoid glucosides (gentiournoside A, gentiournoside E and depressoside) were isolated from the flowers of Gentiana urnula Harry Sm. through activity-guided fractionations with a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All three compounds exhibited excellent DPPH radical scavenging activities (IC₅₀: 10–20 μmol L^?1) comparable to that of ascorbic acid and Trolox. However, examination of the NMR data revealed that the reported chemical structure of depressoside, previously isolated from the leaves of G. depressa, needed correcting due to incorrect elucidation around C-7 of the iridane skeleton, and was corrected to 6-β-(2,3-dihydroxyphenyl)-d-glucosyl 7-O-(2,3-dihydroxybenzoyl)-loganate. Depressoside exhibited a much higher scavenging activity against superoxide radicals (IC₅₀: 45.5 μmol L^?1) than the other two extracted compounds (IC₅₀: more than 900 μmol L^?1) due to the crucial presence of a pyrogallyl unit.     

Divaccinosides A–D,four rare iridoid glucosidic truxillate esters from the leaves of Vaccinium bracteatum

Divaccinosides A–D (1–4), four rare iridoid glucoside cyclodimers in the truxillate forms, were characterized from the leaves of Vaccinium bracteatum. They were presumably biosynthesized from two known iridoid glucoside monomers, vaccinoside (5) and 10-O-trans-p-coumaroyl-6α-hydroxyl-dihydromonotropein (6), via a [2+2] cycloaddition reaction. The structures of the new compounds were established by comprehensive spectroscopic measurements, combined with chemical conversions and single crystal X-ray crystallographic analyses.     

Three New Dimeric Orcinol Glucosides from Curculigo orchioides

Three new phenolic glucosides named orcinosides A, B, and C ( 1, 2 , and 3 , resp.) were isolated in low yields (4.0×10⁻⁶, 11.5×10⁻⁶, 4.5×10⁻⁶%, resp.) from the rhizomes of Curculigo orchioides. Their structures were elucidated by comprehensive spectroscopic analyses including FAB‐MS, HR‐ESI‐MS, IR, and 1D‐ and 2D‐NMR (HSQC, HMBC) data. Compounds 1 – 3 contained two orcinol‐glucoside moieties linked through a CH₂ group.     

Two new secoiridoid glucosides from Syringa velutinai Kom.

Chemical investigation of Syringa velutinai Kom. led to the isolation of two new secoiridoid glucosides. Their structures were identified as 6'-O-(6, 7-dihyrofoliamenthoyl)-8-epi-kingisidic acid (syrveoside A, 1) and 6'-O-menthiafoloyl-8-epi-kingisidic acid (syrveoside B, 2) on the basis of chemical and physicochemical evidence.     

Three New Polyyne (=Polyacetylene) Glucosides from the Edible Roots of Codonopsis cordifolioidea

Three new linear C₁₄ polyyne (=polyacetylene) glucosides, cordifolioidynes A–C ( 1 – 3 ), together with two known polyynes, lobetyol ( 4 ) and lobetyolin ( 5 ), and five known phenylpropanoids, i.e., sinapinaldehyde ( 6 ), coniferaldehyde ( 7 ), coniferoside ( 8 ), sachaliside ( 9 ), and isoconiferin ( 10 ), were isolated from the roots of Codonopsis cordifolioidea. The structures of 1 – 3 were established from spectral evidences and by characterization of their hydrolysis products. Acid hydrolysis of 1 afforded the aglycone 1a , while hydrolysis of 2 and 3 gave the cyclization products 2a and 3a , respectively. Compounds 4 – 10 were isolated from this plant for the first time. The antibacterial activity of compounds 1 – 5 were assessed against eight microbial strains by the agar dilution method, none of them exhibited antibacterial effects at concentrations up to 100 μg/ml.     

Monoterpenoid glucoindole alkaloids and iridoids from Pterocephalus pinardii

A new secondary metabolite, pterocephaline, along with the known cantleyoside, 7α‐morroniside, 3β,5α‐tetrahydrodesoxycordifoline lactam, 5S‐5‐carboxyvincoside, sweroside, and loganin have been isolated from the aerial parts of P. pinardii (Dipsacaceae). Moreover, cantleyoside‐methyl‐hemiacetal and cantleyoside‐dimethyl‐acetal were obtained as seco‐iridoid artifacts. The structures were elucidated by extensive spectroscopic methods including 1D‐(¹H, ¹³C and TOCSY) and 2D‐NMR (DQF‐COSY, HSQC and HMBC). Monoterpenoid glucoindole alkaloids were encountered for the first time in Dipsacaceae family. Copyright © 2010 John Wiley & Sons, Ltd.     

Isoflavone glycosides from the bark of Amorpha fruticosa

Four known isoflavone glucosides have been isolated from the bark of Amorpha fruticosa, which is a traditional remedy plant, for the first time. They were elucidated as 3′-hydroxy-4′-methoxyisoflavone-7-O-β-D-glucopyranoside (1), 4′,6-dimethoxyisoflavone-7-O-β-D-glucopyranoside (2), 4′-methoxyisoflavone-7-O-β-D-glucopyranoside (3), and 3′,5-dihydroxy-4′-methoxyisoflavone-7-O-β-D-glucopyranoside (4), based on the UV, FT-IR, EIMS, FABMS, HREIMS, and NMR (¹H and ¹³C, DEPT, COSY, NOESY, HMQC, and HMBC) data. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 336–338, July–August, 2006.     

Two New Iridoid Glucosides from Clerodendrum serratum

Clerodendrumserratumcalledas"SanDuiJie"inChinese,isasmallshrubwithfragrantflowersfoundwidelyintheforestsofthesouthofChina.IthasbeenusedasafolkmedicineinYunnanfortreatmentofmanydiseasessuchashepatitisandmalaria.Inordertofindthebioactivecomponents,studiesonthechemicalconstituentsoftheleavesofClerodendrumserratum,collectedatLongLingofYunnanprovince,werecarriedout.Wehavereportedtwonewglycosidespreviously'.NoW,furtherinvestigationofglycosidesofthisplantresultedintwonewiridoidglucosides76coumar…     

Simultaneous determination of four shanzhiside methylester derivatives in rabbit plasma by liquid chromatography/tandem mass spectrometry

A simple and sensitive high‐performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous determination of shanzhiside methylester and its three derivatives in rabbit plasma. The method showed good linearity and no endogenous material interfered with the marked compounds and internal standard (IS) capatol peaks. Samples were processed by acetonitrile precipitation. Chromatography was performed using a C₁₈ column (150 × 3.9 mm i.d., 4 µm). The mobile phase consisted of methanol and water (60:40, v/v) during a total run time of 7 min. The main mass parent ions and daughter ions pairs (m/z) for monitoring were: shanzhiside methylester, 429.0/267.4; 8‐O‐acetyl shanzhiside methylester, 470.9/411.3; loganin, 413.2/251.4; phloyoside II, 479.2/281.3; and IS 385.2/203.3. Finally, the method was applied to a pharmacokinetic study of rabbits following intravenous administration of iridoid glycosides extracted from traditional herb Lamiophlomis rotata. Copyright © 2012 John Wiley & Sons, Ltd.