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At least 19 recordsLinked to original sources
PubMed2006

A new anthraquinone from Galium verum L.

A new anthraquinone (4) and three known anthraquinones (1-3) were isolated from Galium verum L. Their structures were identified as 1,3-dihydroxy-2-methylanthraquinone (1), physcion (2), 2-hydroxy-1,3-dimethoxyanthraquinone (3), 2,5-dihydroxy-1,3-dimethoxyanthraquinone (4) by means of chemical and spectroscopic analysis. Compound 2 was isolated from the genus Galium for the first time. In addition, compound 4 was assayed for antimicrobial activity in vitro.

Anthraquinones↗
PubMed2001

Auxin herbicides induce H(2)O(2) overproduction and tissue damage in cleavers (Galium aparine L.).

The phytotoxic effects of auxin herbicides, including the quinoline carboxylic acids quinmerac and quinclorac, the benzoic acid dicamba and the pyridine carboxylic acid picloram, were studied in relation to changes in phytohormonal ethylene and abscisic acid (ABA) levels and the production of H(2)O(2) in cleavers (Galium aparine). When plants were root-treated with 10 microM quinmerac, ethylene synthesis was stimulated in the shoot tissue, accompanied by increases in immunoreactive levels of ABA and its precursor xanthoxal. It has been demonstrated that auxin herbicide-stimulated ethylene triggers ABA biosynthesis. The time-course and dose-response of ABA accumulation closely correlated with reductions in stomatal aperture and CO(2) assimilation and increased levels of hydrogen peroxide (H(2)O(2)), deoxyribonuclease (DNase) activity and chlorophyll loss. The latter parameters were used as sensitive indicators for the progression of tissue damage. On a shoot dry weight basis, DNase activity and H(2)O(2) levels increased up to 3-fold, relative to the control. Corresponding effects were obtained using auxin herbicides from the other chemical classes or when ABA was applied exogenously. It is hypothesized, that auxin herbicides stimulate H(2)O(2) generation which contributes to the induction of cell death in Galium leaves. This overproduction of H(2)O(2) could be triggered by the decline of photosynthetic activity, due to ABA-mediated stomatal closure.

Abscisic Acid↗
PubMed2004

Increases in jasmonic acid caused by indole-3-acetic acid and auxin herbicides in cleavers (Galium aparine).

The effects of indole-3-acetic acid and auxin herbicides on endogenous jasmonic acid (JA) concentrations were studied in relation to changes in ethylene and abscisic acid (ABA) levels in cleavers (Galium aparine). When plants were root-treated with increasing concentrations of indole-3-acetic acid (IAA), ethylene biosynthesis was stimulated in response to the accumulation of endogenous IAA in the shoot tissue. Within 25h of treatment, stimulated ethylene formation was accompanied by increases in immunoreactive concentrations of JA and ABA, which reached maxima of 4.5-fold and 26-fold of the control, respectively, at 100 microM of applied IAA. Corresponding effects were obtained using synthetic auxins and when the ethylene-releasing compound ethephon was applied exogenously. This represents the first report, to our knowledge, of an auxin-mediated increase in JA levels. The increase in JA may be triggered by ethylene.

Abscisic Acid↗
PubMed2005

Physiological and biochemical characterization of quinclorac resistance in a false cleavers (Galium spurium L.) biotype.

The physiological and biochemical basis for quinclorac resistance in a false cleavers (Galium spurium L.) biotype was investigated. There was no difference between herbicide resistant (R) and susceptible (S) false cleavers biotypes in response to 2,4-D, clopyralid, glyphosate, glufosinate-ammonium, or bentazon. On the basis of GR(50) (growth reduction of 50%) or LD(50) (lethal dose to 50% of tested plants) values, the R biotype was highly resistant to the acetolactate synthase (ALS) inhibitor, thifensulfuron-methyl (GR(50) resistance ratio R/S = 57), and quinolinecarboxylic acids (quinclorac R/S = 46), resistant to MCPA (R/S = 12), and moderately resistant to the auxinic herbicides picloram (R/S = 3), dicamba (R/S = 3), fluroxypyr (R/S = 3), and triclopyr (R/S = 2). The mechanism of quinclorac resistance was not due to differences in [(14)C]quinclorac absorption, translocation, root exudation, or metabolism. Seventy-two hours after root application of quinclorac, ethylene increased ca. 3-fold in S but not R plants when compared to controls, while ABA increased ca. 14-fold in S as opposed to ca. 3-fold in R plants suggesting an alteration in the auxin signal transduction pathway, or altered target site causes resistance in false cleavers. The R false cleavers biotype may be an excellent model system to further examine the auxin signal transduction pathway and the mechanism of quinclorac and auxinic herbicide action.

Abscisic Acid↗
PubMed2004

Mechanical adaptations of cleavers (Galium aparine).

BACKGROUND AND AIMS: Cleavers (Galium aparine) is a fast-growing herbaceous annual with a semi-self-supporting, scrambling-ascending growth habit. Mature plants often use upright species for support. It is common in hedgerows and on waste ground. This study aims to characterize the mechanical behaviour of the stem and roots of cleavers and relate this to the arrangement of structural tissue, the net microfibrillar orientations in the cell walls, and plant growth habit. METHODS: The morphology and mechanics of mature cleavers was investigated using plants grown in pots and ones collected from the grounds at the University of Lincoln, Lincoln, UK. Tensile tests were carried out on the stem and the basal section of the first-order lateral roots. The net orientation of cellulose microfibrils in the cell walls was investigated using polarized light microscopy. KEY RESULTS: Results show that the basal regions of the stem and first-order lateral roots were highly extensible. Breaking strains of 24 +/- 7% were recorded for the stem base and 28 +/- 6% for the roots. Anatomical observations showed that the lower stem (base + 100 mm) was circular in cross-section with a solid central core of vascular tissue, whereas further up the stem the transverse section showed a typical four-angled shape with a ring-like arrangement of vascular tissue and sclerenchyma bundles in the corners. The net orientation of wall microfibrils in the secondary xylem diverges from the longitudinal by between 8 and 9 degrees . CONCLUSIONS: The basal region of the stem of cleavers is highly extensible, but the mechanism by which the stem is able to withstand such high breaking strains is unclear; reorientation of the cellulose fibrils in the stem along the axis of loading is not thought to be responsible.

Adaptation, Physiological↗
PubMed1996

Anthraquinones from the polar fractions of Galium sinaicum.

The new anthraquinones, 6,7-dimethoxy xanthopurpurin, 6-hydroxy-7-methoxy rubiadin, 5-hydroxy-6-hydroxymethyl anthragallol 1, 3-dimethyl ether, 7-carboxy anthragallol 1,3-dimethyl ether, anthragallol 1-methyl ether 3-O-beta-D-glucopyranoside, anthragallol 1-methyl ether 3-O-rutinoside, anthragallol 3-O-rutinoside and alizarin 1-methyl ether 2-O-primeveroside were isolated from the CH2Cl2 and n-BuOH extracts of Galium sinaicum roots and their structures were established by various spectroscopic techniques. In addition, two known anthraquinones were also isolated and fully characterized.

Anthraquinones↗
PubMed2000

Triterpene saponins and iridoid glucosides from galium rivale.

Three new glycosides of the oleanene-type triterpenes, rivalosides C-E (1-3), along with three known triterpene saponins, momordin IIb (4) and rivalosides A-B (5-6), and five known iridoid glucosides: monotropein, scandoside, deacetylasperulosidic acid, geniposidic acid and asperulosidic acid, were isolated from aerial parts of Galium rivale. The structures of the new compounds were elucidated by spectral methods and chemical means as 2alpha-acetoxy-3alpha, 19alpha-dihydroxy-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl-(1--> 6)-beta-D-glucopyranoside, 2alpha,3alpha, 19alpha-trihydroxy-olean- 12-en-28-oic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside and 3-O-beta-D-glucuronopyranosyl-24-hydroxy-olean-12-en-28-oic acid 28-O-beta-D-glucopyranoside, for rivalosides C-E, respectively. The taxonomic significance of the rivalosides in G. rivale was discussed.

Glucosides↗
PubMed2002

Antifeedant activity of an anthraquinone aldehyde in Galium aparine L. against Spodoptera litura F.

The insect antifeedant anthraquinone aldehyde nordamnacanthal (1,3-dihydroxy-anthraquinone-2-al) was identified in Galium aparine L., and isolated from the root powder of akane (Rubia akane), a member of the Rubiaceae. Structure-activity relationship (SAR) studies using a series of anthraquinone analogues suggested that the aldehyde group on the anthraquinone was more important than the quinone moiety for antifeedant activity against the common cutworm (Spodoptera litura). High levels of nordamnacanthal were found in the seed leaf stage and in callus tissue induced from seedlings of G. aparine, but its concentration decreased with plant development. Since these compounds are natural pigments for dying textiles, we also evaluated the antifeedant activity against the carpet beetle (Attagenus japonicus ), a textile pest was also evaluated. While nordamnacanthal had strong antifeedant activity against the common cutworm, it did not show any antifeedant activity against the carpet beetle. The most effective antifeedant against the carpet beetle was the major constituent in the extract of R. trictorum, lucidin-3-O-primeveroside, a food pigment.

Aldehydes↗
PubMed2000

Rivalosides A and B, two 19-Oxo triterpenoid saponins from Galium rivale.

Two new oleanene-type triterpene glycosides, rivaloside A (2alpha-acetoxy-3alpha-hydroxy-19-oxo-olean-12-en-28-o ic acid 28-O-beta-glucopyranosyl-(1-->6)-beta-D-glucopyranoside) (1) and rivaloside B (2alpha,3alpha-dihydroxy-19-oxo-olean-12-en-28-oic acid 28-O-beta-glucopyranosyl-(1-->6)-beta-D-glucopyranoside) (2), were isolated from aerial parts of Galium rivale. The structures were determined on the basis of spectroscopic data and chemical transformations. Under alkaline or acid hydrolysis, rivalosides A and B undergo allylic rearrangement with migration of the double bond. These compounds are the first representatives of 19-oxo substituted oleanenes, and they seem to be promising as taxonomic markers for G. rivale.

Carbohydrate Conformation↗
PubMed2004

Antioxidant properties of some medicinal plants: Prangos ferulacea (Apiaceae), Sedum sempervivoides (Crassulaceae), Malva neglecta (Malvaceae), Cruciata taurica (Rubiaceae), Rosa pimpinellifolia (Rosaceae), Galium verum subsp. verum (Rubiaceae), Urtica dioica (Urticaceae).

Antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, reducing powers and the amount of total phenolic compounds of aqueous and/or methanolic extracts of some medicinal plants used in Eastern Turkey were studied. These plants are Prangos ferulacea (CASIR), Sedum sempervivoides (HOROZ LELESI), Malva neglecta (EBEMGUMECI), Cruciata taurica (SARILIK OTU), Rosa pimpinellifolia (KOYUN GOZU), Galium verum subsp. verum (MADAVUR OTU), Urtica dioica (ISIRGAN). The highest peroxidation inhibitions were shown by aqueous extracts of C. taurica and R. pimpinellifolia (IC(50): 0.00022 mg/l and IC(50): 23 mg/l, respectively). However, the highest DPPH radical scavenging activity, reducing power and the amount of phenolic compounds were shown by R. pimpinellifolia. The lowest antioxidant properties were shown by aqueous extract of M. neglecta.

Antioxidants↗
PubMedDate not supplied

Iridoid patterns in Galium L. and some phylogenetic considerations.

From 19 species of Galium, members of 6 European sections of the genus, 24 compounds were isolated, namely 16 iridoid glucosides, 2 secoiridoid glucosides and 6 triterpene saponins (the later found only in G. rivale (Sibth. & Sm. Griseb.) The iridoid content was analyzed by thin layer chromatography - densitometry. An effort was made to clarify interspecies relationships, based on the obtained results and previous data. Generally, a nearly uniform iridoid pattern in the studied species was observed. Nevertheless, some distinctions gave reason the following chemical characters to be treated as taxonomic markers: iridoids, secogalioside (characteristic of G. mollugo group), iridoids V1 and V2 (G. humifusum Bieb. and G. verum L.), 6-acetylscandoside (G. incurvum group and G. verum) and the triterpene saponins, rivalioside A and rivalioside C (characteristic of G. rivale). The studied species regarding to the iridoids could be attributed to three lines of evolutionary differentiation. One line is leading to the differentiation of G. rivale. It contains specific triterpenoids as well as iridoid acids, which show parallel development of both glyceraldehyde 3-phosphate/pyruvate and mevalonate biosynthetic routes in this species. A second line includes G. mollugo and G. incurvum species groups and the species G. humifusum and G. verum. Variety of iridoid esters, hydroxy and carboxy derivatives of iridoids and secoiridoids characterised this line. Third line comprises the remaining studied species, members of different sections and species groups. They posses a nearly identical iridoid pattern, which suggests a convergent evolution regarding to the iridoids.

Asteraceae↗
PubMed1987

The role of nodal and internodal responses in gravitropism and autotropism in Galium aparine L.

This time course and location of gravitropically induced curvatures in stems of goosegrass (Gallium aparine L.), a member of the Rubiaceae, have been investigated. In the early stages of the response (0-5 h), curvature develops throughout the growing region, and is followed by an autotropic straightening which affects the internodes only, leading to the production of essentially straight internodes some 15 h after the onset of gravistimulation. Curvatures developing in the nodal regions, however, continue to increase over this period, and are not subject to reversal by autotropism. The nodal curvatures are not entirely dependent on the presence of any other part of the plant, since marked curvatures can be induced in isolated nodal segments. This pattern of response leads ultimately to correction of the growth direction of the plant by means of curvature responses confined exclusively to the nodes, despite the initial participation of both nodes and internodes in the gravitropic reaction.

Darkness↗