Iridoid patterns in Galium L. and some phylogenetic considerations

GCMS characterization and biological potential of the seeds and aerial part of Galium tricorne Stokes

Abstract Natural products have long been proven very effective against various challenging diseases including cancer and bacterial infections. Galium tricorne is one of the important source of natural products, which has not been explored till date in spite of its profound ethnomedicinal prominence. The current study has been designed to explore the biological potential of G. tricorne and to extract and isolate chemical constituents from its aerial part and seeds respectively along with identification of their chemical constituents. Phytochemical screening was performed to figure out the presence of secondary metabolite in G. tricorne. Crude Methanolic extract (Gt.Crd), which was obtained from the aerial part while the fatty acids were extracted from the seeds, which were later on analyzed by GCMS. Similarly, Well Diffusion and MTT method were used for antibacterial activity and cancer cell line assay respectively. To evaluate the cytotoxic potential, brine shrimps were used. Likewise, in Gas Chromatography-Mass Spectroscopy (GC-MS) analysis a total number of 23 compounds were identified in Gt.Crd extract out of which 7 compounds were sorted out to have some sort of toxicity profile. In the same fashion, 5 fatty acids were identified in the seeds of G. tricorne. Moreover, among the fractions, chloroform fraction (Gt.Chf) exhibited greater zone of inhibition (ZOI) 20.37 mm followed by Gt.Crd 18.40 mm against S. aureus and S. pyogenes respectively. In cytotoxicity Gt.Chf was more active followed by ethyl acetate fraction (Gt.Eta) by exhibiting 88.32±0.62% (LC50=60 µg/mL) and 73.95±2.25% (LC50=80 µg/mL) respectively at 1000 µg/mL concentration of the tested sample. Gt.Chf exhibited greater cell line inhibitory activity (IC50=61 µg/mL) against HeLa cell line. Similarly, Gt.Crd displayed IC50 values of 167.84 µg/mL and 175.46 µg/mL against HeLa and NIH/3T3 cell line respectively. Based on the literature review and screenings, it may be concluded that the aerial part and seeds of G. tricorne are the rich sources of bioactive compounds. The results of the current study also authenticate the scientific background for the ethnomedicinal uses of G. tricorne.

Phytochemical Screening and Antioxidant Activity of Selected Estonian Galium Species

The aim of the present study was to examine three different Galium species from the native population of Estonia, Galium verum, Galium aparine, and Galium mollugo, to characterise their non-volatile and volatile phytochemical composition and antioxidant activity. The main groups of bioactive compounds in the plants were quantified by colorimetric tests, showing high concentrations of polyphenols (up to 27.2 ± 1.5 mg GAE/g), flavonoids (up to 7.3 ± 0.5 mg QE/g) and iridoids (up to 40.8 ± 2.9 mg AE/g). The species were compared using HPLC-DAD-MS/MS, revealing some key differences in the phytochemical makeup of the extracts. The most abundant compound in the extracts of Galium verum blossoms and herb was found to be asperuloside, in Galium aparine herb, asperulosidic acid, and in Galium mollugo herb, chlorogenic acid. Additionally, the composition of volatile compounds was analysed by SPME-GC-MS. The degree of variability between the samples was high, but three volatiles, hexanal, anethole, and β-caryophyllene, were quantified (≥1%) in all analysed samples. The antioxidative activity of all extracts was evaluated using the ORAC_FL method, demonstrating that the Galium species from Estonia all exhibit strong antioxidant capacity (up to 9.3 ± 1.2 mg TE/g). Out of the extracts studied, Galium verum blossoms contained the highest amounts of bioactives and had the strongest antioxidant capacity.

Phytochemical Profiles and In Vitro Immunomodulatory Activity of Ethanolic Extracts from Galium aparine L

Galium aparine L., family Rubiaceae, is a widely spread species in the Galium genus. The herb of G. aparine is part of folk remedies and dietary supplements. In this study, we analyzed the chemical composition and immunomodulatory activities of G. aparine herb ethanolic extracts obtained from the plant material by maceration with 20%, 60% or 96% ethanol. The contents of hydroxycinnamic acid derivatives, flavonoids and polyphenols were determined spectrophotometrically, with extractives and polysaccharides quantified gravimetrically. The qualitative composition was studied using UHPLC-DAD-MS/MS analysis; isolation not previously described in G. aparine quercetin rhamnoglucoside was carried out through column chromatography, and the immunomodulatory activity of extracts was determined in the reaction of lymphocyte blast transformation. Major constitutes of extracts were iridoids, i.e., monotropein, 10-desacetylasperulosidic acid and asperulosidic acid; p-hydroxybenzoic acid; hydroxycinnamic acid derivatives, i.e., 3-O-caffeoylquinic, 5-O-caffeoylquinic, 3,4-O-dicaffeoylquinic, 3,5-O-dicaffeoylquinic, 4,5-O-dicaffeoylquinic acids and caffeic acid derivatives; flavonoids, i.e., rutin, quercetin 3-O-rhamnoglucoside-7-O-glucoside, and isorhamnetin 3-O-glucorhamnoside. Significantly, quercetin 3-O-rhamnoglucoside-7-O-glucoside was first isolated and identified in Galium species so far investigated. All G. aparine herb ethanolic extracts stimulate the transformational activity of immunocompetent blood cells, with 96% ethanolic extract being the most active. The data obtained necessitate further research into the mechanisms of immunomodulatory activity of extracts from G. aparine herb.

Liquid Phase and Microwave-Assisted Extractions for Multicomponent Phenolic Pattern Determination of Five Romanian Galium Species Coupled with Bioassays

Background: Galium is a plant rich in iridoid glycosides, flavonoids, anthraquinones, and small amounts of essential oils and vitamin C. Recent works showed the antibacterial, antifungal, antiparasitic, and antioxidant activity of this plant genus. Methods: For the determination of the multicomponent phenolic pattern, liquid phase microextraction procedures were applied, combined with HPLC-PDA instrument configuration in five Galium species aerial parts (G. verum, G. album, G. rivale, G. pseudoaristatum, and G. purpureum). Dispersive Liquid–Liquid MicroExtraction (DLLME) with NaCl and NAtural Deep Eutectic Solvent (NADES) medium and Ultrasound-Assisted (UA)-DLLME with β-cyclodextrin medium were optimized. Results: The optimal DLLME conditions were found to be: 10 mg of the sample, 10% NaCl, 15% NADES or 1% β-cyclodextrin as extraction solvent—400 μL of ethyl acetate as dispersive solvent—300 μL of ethanol, vortex time—30 s, extraction time—1 min, centrifugation at 12000× g for 5 min. Conclusions: These results were compared with microwave-assisted extraction procedures. G. purpureum and G. verum extracts showed the highest total phenolic and flavonoid content, respectively. The most potent extract in terms of antioxidant capacity was obtained from G. purpureum, whereas the extract obtained from G. album exhibited the strongest inhibitory effect against tyrosinase.

Phytochemical and Pharmacological Properties of Some Species of the Genus Galium L. Galium Verum and Mollugo

Galium verum L. and Galium mollugo L. are perennial herbaceous plants, belonging to the Rubiaceae family. Several classes of bioactive compounds, such as iridoid glycosides, phenolic compounds, anthraquinones and triterpenes, as well as small amounts of tannins, saponins, essential oils have been isolated from Galium species so far. Plants belonging to this genus have a long history of use in a traditional medicine for the treatment of many diseases and conditions. Th e main application of G. verum is as diuretic, choleretic and as the treatment for gout and epilepsy. On the other hand, G. mollugo has been used to treat hysteria, epilepsy, as vulnerary. Over the past decades, numerous papers have been published referring to the chemical constituents presented in G. verum and G. mollugo extracts. Additionally, chemical composition and pharmacological effects of G. verum have been investigated, however data related to the effects of G. mollugo is limited. In this review, we summarized the current knowledge on the phytochemical and pharmacological properties of G. verum and G. mollugo. Finally, we proposed directions for future research in this field, which can improve our understanding of the potential health benefits of Galium species.

Naturally occurring iridoids. A review, part 1

A compilation of new naturally occurring iridoid glycosides, iridoid aglycones, iridoid derivatives and bis-iridoids reported during 1994-2005 is provided with available physical and spectral data: mp, [alpha]D, UV, IR, 1H- and 13C-NMR as well as natural source with family and references. 418 compounds with 202 references are cited.

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.