Iridoid glycosides from Gardeniae Fructus for treatment of ankle sprain

The iridoid glycosides, genipin 1-O-β-d-isomaltoside (1) and genipin 1,10-di-O-β-d-glucopyranoside (2), together with six known iridoid glycosides, genipin 1-O-β-d-gentiobioside (3), geniposide (4), scandoside methyl ester (5), deacetylasperulosidic acid methyl ester (6), 6-O-methyldeacetylasperulosidic acid methyl ester (7), and gardenoside (8) were isolated from an EtOH extract of Gardeniae Fructus. The structures and relative stereochemistries of the metabolites were elucidated on the basis of 1D- and 2D-NMR spectroscopic techniques, high-resolution mass spectrometry, and chemical evidence. Geniposide (4), one of the main compounds of Gardeniae Fructus, was tested for treatment of ankle sprain using an ankle sprain model in rats. From the second to fifth day, the geniposide (4) (100 mg/ml) treated group exhibited significant differences (p < 0.01) with ∼21-34% reduction in swelling ratio compared with those of the vehicle treated control group. This indicated the potential effect of geniposide (4) for the treatment of disorders such as ankle sprain.     

Iridoid glycosides of Cornus canadensis: a comparison with some other Cornus species

The iridoid glycosides scandoside, scandoside methyl ester, monotropein, and galioside were found in Cornus canadensis from several widely distributed collection sites. Cornin and hastatoside were isolated from C. nuttallii. No iridoids were found in C. stolonifera, that instead yielded cornoside and halleridone, also independent of collection location. The results were compared with previous studies and current phylogenetic work on the genus Cornus.     

Iridoids from Scutellaria albida ssp. albida

Three iridoid glycosides, 6'-O-E-p-coumaroylgardoside (1), 6'-O-p-E-coumaroyl-8-epi-loganic acid (2) and scutelloside (3) were isolated from the aerial parts of Scutellaria albida subsp. albida, in addition to an anomeric mixture in equilibrium of one iridoid aglycone (4, 4a), nine iridoid glycosides (5-13), four known phenylethanoid glycosides (14-17), and six known phenolic derivatives (18-23).     

Phlorigidosides A-C, iridoid glucosides from Phlomis rigida

From the aerial parts of Phlomis rigida, three iridoid glucosides, phlorigidoside A (2-O-acetyllamiridoside), B (8-O-acetyl-6-beta-hydroxyipolamide) and C (5-deoxysesamoside), were isolated together with the known iridoid glucosides, shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, deoxypulcheloside I, lamiridoside, and 6-beta-hydroxyipolamide. The structures of the new compounds were elucidated based on spectral and chemical evidence.     

Iridoid glucosides from Randia spinosa (Rubiaceae)

An iridoid glucoside: randinoside, along with five known iridoids: galioside, deacetylasperulosidic acid methyl ester, scandoside methyl ester, geniposide and gardenoside, were isolated from the stems of Randia spinosa. The structures were determined by spectroscopic analysis, including 2D NMR techniques.     

Four iridoids from Randia canthioides

Four new iridoids, 10-dehydrogardenoside, dimeric 10-dehydrogardenoside, randioside and deacetylasperulosidic acid methyl ester aglycone, have been isolated together with three known iridoid glucosides, gardenoside, deacetylasperulosidic acid methyl ester and scandoside methyl ester, from Randia canthioides. It is conceivable that dimeric 10-dehydrogardenoside could be an artefact formed during the isolation process.     

Automated isolation of high-purity plasma albumin for isotope ratio measurements

Measurement of the incorporation of labeled amino acids in plasma albumin, isolated from plasma sampled at different time points after infusion start is a well-known technique to study human albumin synthesis. Unfortunately, no chromatographic method has been described yet, enabling the automated isolation of high-purity albumin from large numbers of plasma samples as is required to study the kinetics of this process. Therefore, we developed a fast protein liquid chromatographic method, capable of processing 200 μl amounts of plasma in 74 min (injection to injection). The system can run unattended as the FPLC system is connected to a sample processor equipped with a polyether ether ketone (PEEK) sample loop and a cooled sample tray. Albumin isolation was divided into three steps. First, plasma samples were injected onto a 1-ml Blue Sepharose HiTrap affinity column, equilibrated with 50 mmol/l phosphate buffer (pH 7.0). After elution of non-binding protein, switching the solvent to phosphate buffer with 1.5 mol/l sodium chloride eluted albumin. The resulting albumin fraction was desalted on-line by directing it through two consecutive HiTrap 5-ml desalting columns, whereafter it was retained in the system within a 5-ml PTFE loop, connected to a motor valve. After switching this valve, thus bypassing the sample loop, the phosphate buffers were changed automatically to Tris buffers. Final purification involved elution of the captured fraction over a 1-ml ion-exchange Resource Q column, using a sodium chloride gradient, ranging from 0 to 0.5 mol/l in Tris buffer (20 mmol/l, pH 7.5). A more than 99% purity of the final albumin fraction was confirmed by capillary electrophoresis.     

Iridoid glucosides from Parentucellia Viscosa

From Parentucellia viscosa a new glucosidic iridoid, gardoside methyl ester, was isolated along with bartioside, aucubin, melampyroside, shanzhiside methyl ester and 8-epiloganin. The structure of the new glucoside was confirmed by its chemical conversion into 8-epiloganin.     

Rapid and sensitive ion-exchange fluorometric measurement of γ-aminobutyric acid in physiological fluids

Improvements of the ion-exchange/fluorometric method for measuring γ-aminobutyric acid (GABA) have resulted in an automatic three-column analyzer which produces an analysis every 15 min using 200-μl samples to a sensitivity of 1 pmol. This high-performance liquid chromatographic procedure utilizes three stainless-steel microbore columns containing cation-exchange resin. GABA is eluted using a lithium citrate buffer and then detected in the flow stream after reaction with the fluorogenic reagent orthophthalaldehyde. Each column utilizes a timer-controlled, pneumatically actuated two-way 10-port valve containing a 200-μl loop for sample injection and a 1-ml loop for regeneration. Similar 4-port valves sequentially direct the output from one of the columns to the reaction manifold. Measurement of GABA levels in sequential aliquets of the first 20 ml of human lumbar cerebrospinal fluid revealed an increasing gradient of GABA level in cerebrospinal fluid from six patients and no gradient in a seventh patient, the mean rate of increase being 2% per milliliter.     

Iridoid allosides from Viburnum opulus

Arbutin and four novel iridoid glycoside esters, named opulus iridoids I–IV, have been isolated from foliage of Viburnum opulus (Caprifoliaceae). Each opulus iridoid constitutes an inseparable mixture of two compounds, differing by containing either 2-methyl- or 3-methylbutyric acid in ester linkage at the 1-OH-group in an iridoid glycoside. In all glycosides 2′,3′-di-O-acetyl-β-D-allopyranose is linked through a glycosidic bond to C-11 in the iridoid aglycone. The opulus iridoids differ by the degree of acetylation of the aglycone and by the attachment, in III and IV, of a β-D-xylopyranosyl group at C-4 of the allose moiety. The structures have been elucidated by ¹H and ¹³C-NMR spectroscopy and by cleavage of the glycosidic linkage with boron trifluoride etherate in acetic anhydride, yielding the acetates of the cyclized aglycone and of the appropriate mono- or disaccharide. This is the second report of an iridoid attached to a sugar other than glucose and the second time allose has been encountered in higher plants. The systematic position of Viburnum is briefly discussed.     

Two new iridoid glucosides from Mussaenda parviflora and Mussaenda shikokiana

From the leaves of Mussaenda parviflora, two new iridoid glucosides, mussaenoside and shanzhiside methyl ester were isolated and their structures e     

Iridoid glucosides from Phlomis rotata

Two new iridoid glucosides, dehydropentstemoside and 7-epiphlomiol have been isolated from the aerial parts of Phlomis rotata and their structures elucidated by means of chemical and spectral methods. Shanzhiside methyl ester and barlerin have also been isolated and identified     

Dodecyl maltoside-sodium dodecyl sulfate two-dimensional polyacrylamide gel electrophoresis of chloroplast thylakoid membrane proteins

A two-dimensional electrophoretic system has been developed for the separation of chloroplast thylakoid membrane proteins. This system incorporates nondenaturing polyacrylamide gel electrophoresis in the presence of the nonionic detergent dodecyl-beta-D-maltoside in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. Thylakoid membranes isolated from Spinacia oleracea were solubilized in 1.0% dodecyl-beta-D-maltoside and separated in 4-7% linear acrylamide gradient tube gels which contained 0.05% dodecyl-beta-D-maltoside. After electrophoresis, the tube gels were equilibrated with a sodium dodecyl sulfate-containing equilibration buffer and applied to a 12.5-20% acrylamide linear gradient gel. The Lammelli buffer system was used in both dimensions. The two-dimensional gels were analyzed by staining sequentially with 3,3',5,5'-tetramethylbenzidine-H2O2, Coomassie blue, and silver staining. A number of protein components were identified on "Western blots" of these two-dimensional gels by immunological localization. Membrane protein complexes such as the light-harvesting chlorophyll a/b protein complex, photosystem I, photosystem II, the cytochrome b6/f complex and ribulose bisphosphate carboxylase appear to migrate as essentially intact complexes in the first dimension and appear as vertical series of resolved subunits in the second dimension. This technique complements isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis in providing additional information concerning the subunit composition of membrane protein complexes and may prove to be of general utility for studying the protein composition of other membrane systems.     

Iridoid and bisiridoid glycosides from Globularia cordifolia

From the methanolic extract of the underground parts of Globularia cordifolia, a new iridoid glycoside, 5-hydroxydavisioside (1) and a new bisiridoid glycoside, globuloside C (2) were isolated along with six known iridoid glycosides, aucubin, melampyroside, monomelittoside, globularifolin, alpinoside and asperuloside. The structures of the isolates were established by 1D and 2D NMR spectroscopy in combination with IR, UV and MS analyses.     

Automated multi-dimensional liquid chromatography: sample preparation and identification of peptides from human blood filtrate

A comprehensive on-line sample clean-up with an integrated two-dimensional HPLC system was developed for the analysis of natural peptides. Samples comprised of endogenous peptides with molecular weights up to 20 kDa were generated from human hemofiltrate (HF) obtained from patients with chronic renal failure. The (poly-)peptides were separated using novel silica-based restricted access materials with strong cation-exchange functionalities (SCX-RAM). The size-selective sample fractionation step is followed by cation-exchange chromatography as the first dimension. The subsequent second dimension of separation is based on hydrophobic interaction using four parallel short reversed-phase (RP) columns implemented via a fully automated column switching technique. More than 1000 peaks were resolved within the total analysis time of 96 min. Substances of selected peaks were sampled to analyse their molecular weights by off-line MALDI-TOF mass spectrometry and to determine their amino acid sequence by Edman degradation. The potential for comprehensive peptide mapping and identification is demonstrated.     

Sensitive column-switching high-performance liquid chromatography method for determination of propiverine in human plasma

A sensitive column-switching high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed for the determination of propiverine in human plasma. Propiverine and internal standard, oxybutynin, were extracted from human plasma that had been made basic with 5N sodium hydroxide into methyl tert-butyl ether. The extracted plasma sample was injected onto the HPLC system consisting of a pretreatment column, a concentrating column, and an analytical column, which were connected with a six-port switching valve. The assay was linear in concentration ranges of 2-200 ng/ml for propiverine in human plasma. This method showed excellent sensitivity (a limit of detection of 0.5 ng/ml), good precision and accuracy. This method is suitable for bioequivalence studies following single dose in healthy volunteers.     

Evaluation of human neutrophil elastase inhibitory effect of iridoid glycosides from Hedyotis diffusa

Five iridoid glycosides were isolated from the MeOH extract of Hedyotis diffusa, and their structures were elucidated as E-6-O-p-methoxycinnamoyl scandoside methyl ester (1), Z-6-O-p-methoxycinnamoyl scandoside methyl ester (2), E-6-O-p-feruloyl scandoside methyl ester (3), E-6-O-p-coumaroyl scandoside methyl ester (4), and Z-6-O-p-coumaroyl scandoside methyl ester (5) by interpretation of their spectroscopic data. All the isolated compounds were evaluated for human neutrophil elastase inhibitory effect, and compound 1 showed potent activity with an IC₅₀ value of 18.0 μM. The molecular docking simulation suggested a structural model for the inhibition of human neutrophil elastase by compound 1.     

4'-deoxy iridoid glycosides from Centranthus longiflorus

The new iridoid glycosides, 4'-deoxykanokoside A and 4'-deoxykanokoside C, were isolated from the methanolic root extract of Centranthus longiflorus ssp. longiflorus. They were accompanied by the three known iridoid glycosides, kanokoside A, kanokoside C and valerosidatum, and two known phenylpropanoid glycosides, coniferin and isoconiferinoside. The structures were elucidated mainly by spectroscopic methods. The presence of 4-deoxy glucose as a part of plant glycosides is rather unusual. Cytotoxic effects of the isolated compounds were also investigated.     

Melanogenesis-inhibitory saccharide fatty acid esters and other constituents of the fruits of Morinda citrifolia (noni)

Five new saccharide fatty acid esters, named nonioside P (3), nonioside Q (4), nonioside R (8), nonioside S (10), and nonioside T (14), and one new succinic acid ester, butyl 2-hydroxysuccinate (=4-butoxy-3-hydroxy-4-oxobutanoic acid) (31), were isolated, along with 26?known compounds, including eight saccharide fatty acid esters, 1, 2, 5, 6, 7, 9, 12, and 13, three hemiterpene glycosides, 15, 17, and 18, six iridoid glycosides, 21-25, and 27, and nine other compounds, 20, 28, 29, and 32-37, from a MeOH extract of the fruit of Morinda citrifolia (noni). Upon evaluation of these and five other glycosidic compounds, 11, 16, 19, 26, and 30, from M. citrifolia fruit extract for their inhibitory activities against melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), most of the saccharide fatty acid esters, hemiterpene glycosides, and iridoid glycosides showed inhibitory effects with no or almost no toxicity to the cells. These compounds were further evaluated with respect to their cytotoxic activities against two human cancer cell lines (HL-60 and AZ521) and their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells.     

Chemical constituents of Barleria prionitis and their enzyme inhibitory and free radical scavenging activities

From the aerial parts of Barleria prionitis, one new phenylethanoid glycoside, barlerinoside (1) along with six known iridoid glycosides, shanzhiside methyl ester (2), 6-O-trans-p-coumaroyl-8-O-acetylshanzhiside methyl ester (3), barlerin (4), acetylbarlerin (5), 7-methoxydiderroside (6), and lupulinoside (7) were isolated. Structures of these compounds were elucidated with the aid of extensive NMR spectral studies and chemical reactions. Compound 1 was significantly active in glutathione S-transferase (GST) inhibition assay with an IC₅₀ value of 12.4 μM but weakly active in acetylcholinesterase (AChE) inhibition assay. Compounds 2–7 also exhibited different levels of GST, AChE inhibitory and free radical scavenging activities.