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PubMed2003

Iridoids from Scrophularia buergeriana attenuate glutamate-induced neurotoxicity in rat cortical cultures.

In previous work, we isolated 7 neuroprotective iridoid glycosides from the 90% MeOH fraction of Scrophularia buergeriana (Scrophulariaceae). We therefore investigated the mode of action of 8-O-E-p-methoxycinnamoyl-harpagide (8-MCA-Harp), the most potent neuroprotective iridoid, and its aglycone, harpagide (Harp) using primary cultures of rat cortical cells in vitro. 8-MCA-Harp only revealed its neuroprotective activity in a pretreatment paradigm; this iridoid had more selectivity in protecting neurons against N-methyl-D-aspartate (NMDA)-induced neurotoxicity as opposed to that induced by kainic acid (KA). On the other hand, Harp exerted significant neuroprotective activity when it was administered either before or after glutamate insult and protected cultured neuronal cells from neurotoxicity induced by NMDA or KA. Furthermore, Harp significantly prevented the decrease of glutathione, an antioxidative compound in the brain, in our cultures. Finally, 8-MCA-Harp and Harp could successfully reduce the overproduction of nitric oxide and the level of cellular peroxide in cultured neurons. Collectively, these results suggested that Harp and 8-MCA-Harp protected primary cultured neurons against glutamate-induced oxidative stress primarily by acting on the antioxidative defense system and on glutamatergic receptors, respectively.

Animals↗
PubMed2006

Occurrence of iridoid glycosides in in vitro cultures and intact plants of Scrophularia nodosa L.

Shoot, root, and callus cultures of Scrophularia nodosa L. (Scrophulariaceae) were established and cultivated in vitro. Iridoid glycosides, such as harpagoside, aucubin, and catalpol were identified by LC-ESI-MS and their contents determined by HPLC. For comparison intact plants of S. nodosa were analysed. In shoot cultures slightly lower amounts of detectable iridoid glycosides (4.36% dry weight) were determined than in the field grown plants (4.88%). Concentration of harpagoside was highest in leaves of field plants (1.05%) and in flowers of in vitro plantlets (1.10%). For aucubin the highest amount was found in the leaves of in vitro plantlets (1.67%) whereas the levels of aucubin in the leaves of field plants were remarkably lower. Catalpol was produced as a trace compound in intact plants and shoot cultures. Callus and root cultures were apparently not able to synthesise iridoid glycosides.

Culture Media↗
PubMed1996

Inhibitory effect of iridoids on Epstein-Barr virus activation by a short-term in vitro assay for anti-tumor promoters.

The in vitro anti-tumor promoting effect of the methanolic extracts of iridoids containing three plants and several pure iridoids isolated from other plants, has been evaluated. The alcoholic extracts of Paederia scandens, P. scandens var. mairei and the Ayurvedic herbal remedy Picrorhiza kurrooa were tested against the Epstein-Barr virus. Among the 15 iridoids evaluated, the glycoside, paederoside, displayed the highest order of anti-tumor promoting activity.

Anticarcinogenic Agents↗
PubMed2004

Iridoid glucosides of Paederota lutea and the relationships between Paederota and Veronica.

In a chemical investigation of the water soluble compounds in Paederota lutea eight known iridoids were isolated together with a new one with a 8,9-double bond, namely paederotoside (10-O-benzoyl-6'-O-alpha-arabino(1-->6)-beta-glucopyranosyl arborescosidic acid) and the 6-hydroxy-flavone glucoside 4'-O-methylscutellarein 7-O-beta-glucopyranoside. The known iridoid glucosides were 8-epiloganic acid, gardoside, aucubin, catalpol and the 6-O-esters of catalpol: veronicoside, catalposide, amphicoside and verproside. The compounds isolated show that Paederota has a glycoside content almost identical to that of a general Veronica species, and this is in good agreement with the results from recent investigations of the phylogeny of Veronica and its closest relatives, where Paederota is placed as a sister-group next to Veronica. In an analysis of the iridoid glucosides from some of these relatives, it is shown that Veronica, Paederota, Picrorhiza and Veronicastrum are all characterized by containing 6-O-esters of catalpol. Some less closely related taxa namely: Lagotis, Wulfenia, Plantago, Aragoa and Globularia instead contain 10-O-esters of catalpol or aucubin.

Iridoids↗
PubMed2005

Iridoid glucosides from Kickxia abhaica D.A. Sutton from Scrophulariaceae.

Two iridoid glucosides namely; 6-acetylantirrinoside (1), 6'-O-p-hydroxybenzoylantirrinoside (2) were isolated from the aerial parts of Kickxia abhaica. Beside that, three known iridoid glucosides, antirrinoside (3), antirride (4) and mussaenosidic acid (5), one flavone glycoside (6) and a hexitol, d-mannitol (7) were isolated. The structures of the iridoid glucosides 1-2 were established by 1D and 2D NMR spectral data, including COSY, HMQC and HMBC experiments, as well as HRMS.

Glucosides↗
PubMed2003

Determination of five major iridoid glucosides in Flos Lonicerae by high-performance liquid chromatography coupled with evaporative light scattering detection.

This study presents a new HPLC method using evaporative light scattering detection for the simultaneous determination of live major iridoid glucosides, namely 7-epi-loganin, sweroside, loganin, 7-epi-vogeloside, and secoxyloganin in Flos Lonicerae, an important traditional Chinese medicinal herb. The optimal conditions of separation and detection were achieved on a C18 analytical column with an isocratic mobile phase consisting of methanol-water (30:70, v/v) containing 0.5% acetic acid at the flow-rate of 1.0 ml/min, temperature for the detector drift tube set at 90 degrees C and the nitrogen flow-rate of 2.6 l/min. The limit of detection (S/N = 3) is less than 35.1 microg/ml and the limit of quantification (S/N = 10) is less than 140.1 microg/ml. All calibration curves show good linear regression (r2>0.996) within test ranges. This method provides good reproducibility for the quantification of the major iridoid glucosides in four Lonicera species with overall intra- and inter-day variation of less than 5% and 9%, respectively. The assay was successfully applied to quantify the main iridoid glucosides in the herb and to identify the botanical origin of Flos Lonicerae.

Chromatography, High Pressure Liquid↗
PubMed2002

Iridoid glucosides from roots of Vietnamese Paederia scandens.

Four iridoid glucosides, three of which are dimeric were isolated from the methanol extract of roots of Vietnamese Paederia scandens (Lour) Merrill together with the five known glucosides, paederoside, asperuloside, paederosidic acid, asperulosidic acid and geniposide. Seven sulfur-containing iridoid glucosides were also isolated. The structures of the iridoid glucosides were determined by a combination of high-resolution NMR, MS, IR and UV spectra, and chemical reaction such as acetylation.

Acetylation↗
PubMed2003

New unusual iridoids from the leaves of noni (Morinda citrifolia L.) show inhibitory effect on ultraviolet B-induced transcriptional activator protein-1 (AP-1) activity.

A novel iridoid dimer in whose structure the two iridoid units are connected by a rare ether group, together with two new unusual iridoids showing significant inhibition of UVB-induced Activator Protein-1 (AP-1) activity in cell cultures, have been isolated from the leaves of noni (Morinda citrifolia L.). Their structures were determined on the basis of detailed high-field 1D and 2D spectral analysis. Their inhibitory effect on UVB-induced transcriptional Activator Protein-1 (AP-1) activity are also discussed.

Animals↗
PubMed2002

Hydrophilic carboxylic acids and iridoid glycosides in the juice of American and European cranberries (Vaccinium macrocarpon and V. oxycoccos), lingonberries (V. vitis-idaea), and blueberries (V. myrtillus).

Analysis of the hydrophilic fraction of cranberry juice by reversed-phase HPLC using an Aqua LUNA column with diode array or MS detection revealed the presence of quinic acid, malic acid, shikimic acid, and citric acid. For the first time, two iridoid glucosides were found in the juice. The two iridoid glucosides were shown to be monotropein and 6,7-dihydromonotropein by MS and NMR spectroscopy. A fast reversed-phase HPLC method for quantification of the hydrophilic carboxylic acids was developed and used for analyses of cranberry, lingonberry, and blueberry juices. The level of hydrophilic carboxylic acids in cranberries was 2.67-3.57% (w/v), in lingonberries 2.27-3.05%, and in blueberries 0.35-0.75%. In lingonberries both iridoid glucosides were present, whereas only monotropein was present in blueberries.

Beverages↗
PubMed2002

Four new neuroprotective iridoid glycosides from Scrophularia buergeriana roots.

Four new iridoid glycosides were isolated from a 90% MeOH extract of Scrophularia buergeriana roots and characterized as 8-O-E-p-methoxycinnamoylharpagide (1), 8-O-Z-p-methoxycinnamoylharpagide (2), 6'-O-E-p-methoxycinnamoylharpagide (3), and 6'-O-Z-p-methoxycinnamoylharpagide (4), respectively. In addition, three known iridoids were identified as E-harpagoside (5), Z-harpagoside (6), and harpagide (7). Compounds 1-7 significantly attenuated glutamate-induced neurotoxicity when added to primary cultures of rat cortical cells at concentrations ranging from 100 nM to 10 microM. The results obtained indicate that the iridoid glycosides isolated from S. buergeriana have significant protective effects against glutamate-induced neurodegeneration in primary cultures of rat cortical neurons.

Animals↗
PubMed2000

Bis-iridoid glucosides from Abelia chinensis.

Seven bis-iridoid glucosides have been isolated from Abelia chinensis and were characterized by having a secoiridoid residue as unit A esterifying a C(10)-iridoid or a delta-lactone iridoid as unit B. Among these, compounds 1-3 are new and correspond to 7-O-acetyllaciniatoside IV, 7-O-acetyllaciniatoside V, and 7-O-acetylabelioside B, respectively. The structures of 1-3 were elucidated by spectral methods.

Glucosides↗
PubMed2002

Iridoid glycosides from Globularia davisiana.

From the ethanolic extract of the aerial parts of Globularia davisiana, a new iridoid glycoside, davisioside (1), was isolated. Davisioside (1) comprises a rare iridoid aglycone structure with a saturated double bond between C-3 and C-4. Nine known iridoid glycosides, asperuloside (2), alpinoside (3), geniposide (4), globularin (5), globularicisin (6), 10-O-benzoylcatalpol (7), lytanthosalin (8), melampyroside (9), agnuside (10), and three known phenylethanoid glycosides, verbascoside, isoacteoside and leucosceptoside A were also isolated and characterized. The structures of the isolates were established by spectroscopic methods (one-dimensional (1D)- and two-dimensional (2D)-NMR, MS).

Biphenyl Compounds↗
PubMed2006

Iridoid glucosides from Wendlandia tinctoria roots.

Four new iridoid glucosides, 5-dehydro-8-epi-adoxosidic acid, 5-dehydro-8-epi-mussaenoside, 10-O-dihydroferuloyldeacetyldaphylloside, and wendoside, together with one known iridoid glucoside, 8-epi-mussaenoside, beta-D-glucose, D-mannitol and beta-sitosterol have been isolated from the roots of Wendlandia tinctoria. On the basis of chemical and spectral analyses, the structures of new iridoid glucosides have been elucidated.

Acetates↗
PubMed2006

Iridoids from Neopicrorhiza scrophulariiflora and their hepatoprotective activities in vitro.

Four new non-glycosidic iridoids, piscrocins D (1), E (2), F (6), and G (7), as well as two new iridoid glycosides, piscrosides A (8) and B (9), were isolated from the roots of Neopicrorhiza scrophulariiflora (Scrophulariaceae), together with seven known iridoids. The structures of the isolated compounds were established by means of 1D and 2D NMR spectroscopy and chemical methods. The hepatoprotective activities of these compounds were evaluated by measuring their effects on CCl(4)-induced hepatocytes damage in vitro, and the structure-activity relationships were also discussed.

Animals↗
PubMedDate not supplied

Iridoids from Scrophularia genus.

We report here an updated summary about iridoid composition of a series from the genus Scrophularia which have been investigated until now from a phytochemistry point of view. In addition a list is included about iridoids isolated in our laboratory from different plant parts of Scrophularia scorodonia L., which are compared with iridoids from some species of the Scrophularia genus. The present study may serve as a current information to researchers working on phytochemistry and pharmacological aspects from the Scrophularia genus and possibly to serve as a new starting point for future investigations.

Asteraceae↗
PubMed2001

Iridoids from Phlomis umbrosa.

Two epimeric pairs of iridoid aglycones, named shanzhigenin methyl ester and 1-epishanzhigenin methyl ester, and 8-acetylshanzhigenin methyl ester and 8-acetyl-1-epishanzhigenin methyl ester, were isolated from Phlomis umbrosa roots, along with five known iridoid glucosides. The four iridoid aglycones are reported for the first time from a natural source. Their structures were established by spectroscopic methods, mainly 1D- and 2D-NMR spectroscopic experiments, and chemical methods.

Acetylation↗
PubMed1996

Neuritogenic effect of natural iridoid compounds on PC12h cells and its possible relation to signaling protein kinases.

We examined effect of iridoid glucosides, aucubin, catalpol, geniposide and gardenoside, and their enzymic hydrolysates on neurite outgrowth of PC12h cells. Except for aucubin, these glucosides induced neurite outgrowth at 0.1 microgram/ml and above in medium after 3 d of treatment. Hydrolysates of the four glucosides all caused neuritogenesis. Geniposide hydrolysate enhanced responses of cells to carbachol and KCl-induced depolarization in terms of cytoplasmic free-calcium concentration. The aglucone of geniposide, genipin, also promoted neurite outgrowth in a dose-dependent manner (ED50 = 0.7 microM). The neuritogenic effect of genipin was partially or considerably inhibited in the presence of H-89 and genistein. All the results presented suggest that certain iridoid compounds can induce neuronal differentiation in PC12h cells through activation of components of the intracellular signal transduction pathway.

Animals↗
PubMed1996

Iridoid glycosides from Thunbergia grandiflora.

The novel iridoid glycosides, isounedoside and grandifloric acid, were isolated from Thunbergia grandiflora. Grandifloric acid contains C-10 as a carboxylic acid group, the presence of which was predicted by recent iridoid biosynthesis studies carried out within T. alata. Isounedoside contains a rare 6,7-epoxide functional group. A revision in some of the NMR spectral assignments for the known iridoid glycoside alatoside was also made.

Diterpenes↗