Iridoid glucosides from Melampyrum

Melampyrum arvense and M. cristatum contain, besides aucubin, 8-epiloganin and melampyroside, a new natural iridoid glucoside: gardoside methyl ester. In addition, M. arvense contains mussaenoside and M. cristatum mussaenosidic acid, another novel iridoid glucoside.     

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.     

Iridoid glucosides from Thunbergia laurifolia

Two iridoid glucosides, 8-epi-grandifloric acid and 3′-O-β-glucopyranosyl-stilbericoside, were isolated from the aerial part of Thunbergia laurifolia along with seven known compounds, benzyl β-glucopyranoside, benzyl β-(2′-O-β-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl β-glucopyranoside, hexanol β-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin. Strucural elucidation was based on the analyses of spectroscopic data.     

Iridoid glucosides from Strychnos nux-vomica

From seeds of Strychnos nux-vomica three iridoids, 6'-O-acetylloganic acid, 4'-O-acetylloganic acid and 3'-O-acetylloganic acid were isolated together with two known iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.     

Iridoid glucosides from Satureja Vulgaris

Satureja vulgaris was shown to contain two new iridoid glucosides, 5-deoxylamiol and 4-methylantirrhinoside, as well as the known iridoid glucosides lamiol and 5-deoxylamioside. The structures of the new glucosides were established by spectroscopic studies and chemical evidence.     

Iridoid glucosides from Barleria lupulina

From the aerial part of Barleria lupulina, 8-O-acetyl-6-O-trans-p-coumaroylshanzhiside, saletpangponosides A-C and 8-O-acetylmussaenoside were isolated together with 13 known compounds. The structural elucidations were based on analyses of physical and spectroscopic data.     

Iridoid glucosides from clerodendrum incisum

8-O-Foliamenthoyleuphroside and 2′-O,8-O-difoliamenthoyleuphroside, new foliamenthic acid esters of euphroside, and the known iridoid euphroside have been isolated from the leaves and twigs of Clerodendrum incisum. From the roots of the same plant the known iridoid plantarenaloside has been isolated. The taxonomic significance of these findings is discussed.     

Iridoid glucosides from Pedicularis

Pedicularis palustris contains the iridoid glucosides aucubin and gardoside methyl ester, and five hydroxy derivatives of 8-epi-deoxyloganin, together with boschnaloside and three hydroxy derivatives of boschnaloside. From P. silvatica, plantarenaloside, 8-epiloganin and euphroside have been isolated. Euphroside is also present in P. lapponica, in addition to aucubin and mussaenoside. Chemical evidence for the structure of euphroside is presented. Pedicularioside is shown to be identical with penstemoside, and the former name is thus redundant.     

Micropropagation of the Mediterranean species Viburnum tinus

In vitro propagation of the Mediterranean species Viburnum tinus L. was established from an outdoor-grown shrub. Two standard macrosalt formulations (Margara N30K and Murashige and Skoog), a range of benzyladenine and sucrose concentrations were tested for their effect on shoot multiplication. The cytokinin concentration was the most important factor affecting shoot multiplication. The highest shoot multiplication rate was obtained from single-node explants cultured on Murashige and Skoog medium supplemented with 4.4 M benzyladenine. Cytokinin concentration and an interaction of macrosalts and benzyladenine influenced shoot length on the multiplication stage: best shoot growth was observed on MS medium containing 1.1 M benzyladenine. In addition, sucrose concentrations of 87.6–146.0 mM gave the highest multiplication rates and improved shoot growth. Following a shoot ellongation stage, single shoots were rooted on media containing naphtaleneacetic acid (1.3–5.4 M). Although enhanced in vitro rooting was obtained on media containing 5.4 M naphtaleneacetic acid, reducing the auxin concentration to 1.3 M during the in vitro rooting stage improved acclimatisation frequency and further plant growth in a horticultural substrate.     

Phytochemical constituents and hepatoprotective activity of Viburnum tinus

From the leaves of Viburnum tinus L. (Adoxaceae) two acylated iridoid glucosides (viburtinoside A and B), a coumarin diglucoside scopoletin 7-O-beta-D-sophoroside and a natural occurred dinicotinic acid ester 2,6-di-C-methyl-nicotinic acid 3,5-diethyl ester were isolated. In addition to these, 10 known compounds were isolated, namely two bidesmosidic saponins, a hexamethoxy-flavone and five flavonol glycosides, as well as suspensolide A and oleanolic acid were isolated for the first time in this genus and species, respectively. The structures were determined mainly by spectroscopic methods (UV, IR, ESI-MS, 1H-, 13C NMR and DEPT). Toxicity of the investigated extract was determined (LD50=500 mg/kg). CCl4-induced hepatotoxicity has been evaluated in terms of the determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid peroxide and nitric oxide levels in serum and compared using adult male rats weighing 150-180 g. Their highly elevated levels were significantly reduced by treatment with the investigated aqueous methanol extract in dose-dependent manner.     

Iridoid glucosides from Thunbergia laurifolia

Two iridoid glucosides, 8-epi-grandifloric acid and 3′-O-β-glucopyranosyl-stilbericoside, were isolated from the aerial part of Thunbergia laurifolia along with seven known compounds, benzyl β-glucopyranoside, benzyl β-(2′-O-β-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl β-glucopyranoside, hexanol β-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin. Strucural elucidation was based on the analyses of spectroscopic data.     

Iridoid glucosides from Campsis chinensis

Two new iridoid glucosides, 5-hydroxycampenoside and cachineside I, were isolated together with tecomoside from leaves of Campsis chinensis and their structures were elucidated. The absolute stereochemistry of 5-hydroxycampenoside has been established by X-ray analysis, and the structural correlation between 5-hydroxy-campenoside and tecomoside has been determined by spectral and chemical experiments.     

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     

Iridoid glucosides in fouquieriaceae

From three Fouquieria sp. 12 iridoid glucosides were isolated and identified. Eight of these were structurally related to galioside (monotropein methylester), while four were hydroxy substitution products of deoxyloganin. In three cases the glucoside occurred together with the corresponding 10-O-acetate.     

Iridoid glucosides from Veronica pectinata var. glandulosa

A new highly oxygenated iridoid glucoside, urphoside B (1) was isolated from the Veronica pectinata var. glandulosa together with seven known iridoid glucosides, aucubin, catalpol, veronicoside, catalposide, verproside, amphicoside and 6-O-veratroyl catalpol. The planar as well as the stereo structures of the isolated compounds were determined by means of extensive 1D- and 2D-NMR spectroscopy and confirmed by HR-Mass.     

Iridoid glucosides with insecticidal activity from Galium melanantherum

The insecticidal activity of the endemic species Galium melanantherum was evaluated against Crematogaster scutellaris ants and Kalotermes flavicollis termites. Iridoid glucosides 1-7 were isolated for the first time as metabolites of the investigated plant, along with the coumarin scopolin. The main components of the extract were found to be the non-acetylated iridoids: geniposidic acid (1), 10-hydroxyloganin (2), deacetyldaphylloside (3), monotropein (4), deacetylasperulosidic acid (5) and scandoside (6), while asperulosidic acid (7) was present only in minute quantities. All isolated metabolites were identified on the basis of their spectral data. Laboratory bioassays revealed significant levels of toxicity for 1-4 against Kalotermes flavicollis termites and Crematogaster scutellaris ants.     

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.     

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.