Three new coumarins and a new coumarin glycoside from Micromelum integerrimum / 中国天然药物

Three new coumarins, integmarins A-C (1-3), and a new coumarin glycoside, integmaside A (4) were isolated from the leaves and stems of Micromelum integerrimum. Their structures were elucidated on the basis of 1D and 2D NMR and MS data, and their absolute configurations were assigned according to the ECD data of the in situ formed transition metal complexes and comparison of experimental and calculated ECD data. Compounds 1 and 2 are two rare coumarins with butyl and propyl moieties at the C-6 position; compound 3 is a novel coumarin with a highly oxidized prenyl group, and compound 4 is a rare bisdihydrofuranocoumarin glycoside.

New seminal variety of Stevia rebaudiana: Obtaining fractions with high antioxidant potential of leaves

ABSTRACT The aim of this study was to determine the composition and antioxidant potential of leaves of a new variety of Stevia rebaudiana (Stevia UEM-13). Stevia leaves of UEM-13 contain rebaudioside A as the main glycoside, while most wild Stevia plants contain stevioside. Furthermore can be multiplied by seed, which reduces the cost of plant culture techniques as other clonal varieties are multiplied by buds, requiring sophisticated and expensive seedling production systems. Ethanol and methanol were used in the extraction to determine the bioactive compounds. The methanolic extract was fractionated sequentially with hexane, chloroform, ethyl acetate and isobutanol, and the highest concentration of phenolic compounds and flavonoids was obtained in the ethyl acetate fraction (524.20 mg galic acid equivalent/g; 380.62 µg quercetin equivalent/g). The glycoside content varied greatly among the fractions (0.5% - 65.3%). Higher antioxidant potential was found in the methanol extract and the ethyl acetate fraction with 93.5% and 97.32%, respectively. In addition to being an excellent source for obtaining of extracts rich in glycoside, this new variety can also be used as raw material for the production of extracts or fractions with a significant amount of antioxidant activity and potential to be used as additives in food.

Special metabolites isolated from Urochloa humidicola (Poaceae)

ABSTRACT This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-β-d-glucopyranoside and methyl quercetin-3-O-β-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-β-d-glucopyranosyl-penogenin, as well as catechin-7-O-β-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.

Phytochemical and pharmacological evaluation of some selected medicinal plants

The medicinal plants most commonly cultivated and medicinally useful [like Annona squamosa, Coleus forskohlii, Cissus quadrangularis, Desmodium gangeticum and Stevia rebaudiana] were selected for physicochemical, phytochemical and pharmacological studies. Physicochemical values for these medicinal plants like total ash content, acid-insoluble ash, sulphate ash, water-soluble ash, loss on drying and solubility percentage were evolved. Qualitative phytochemical tests were carried out for all these medicinal plants. Quantitative estimation of major biological active compounds, total alkaloid, total glycosides and total terpenoids was carried out. Antibacterial and antifungal activities against E. coli, Streptococcus aureus, Staphylococcus pyogenes, Enterococcus faecalis, Aspergillus niger and A. flavus were studied. TLC profiles of alcoholic extracts of all these medicinal plants were established

Triterpenoidic glycosides from Caryota urens

From the leaves of Caryota urens, two new triterpenoidic glycosides along with two known compounds have been isolated. Their structures were elucidated by chemical and physical data. [IR. [1]H-NMR, [13]CNMR and Mass Spectra]

Role of Ca2+ on uterine force stimulated by a glycoside from the root of Dalbergia saxatilis.

Uterine muscle contraction is dependent on external Ca2+ and Ca2+ release from cytoplasmic storage sites. In this study, the mechanism of Ca2+ mobilization in uterine muscle cells by glycoside, dalsaxini, isolated from the root of D. Saxatilis was investigated in the rat. Uterine muscle contractility stimulated by dalsaxin was concentration dependent (ED50 0.13 mg/ml) and was significantly attenuated (85%; P < 0.01) in Ca(2+)-free physiological solution and in solutions containing verapamil (0.06-0.48 mumol). The small transient contraction observed in Ca(2+)-free medium was further suppressed by caffeine (2 mmol) and completely abolished in solutions containing Lanthanum chloride [(La3+), 2 mmol]. Contractions stimulated by the glycoside were unaffected by amiloride (50-83 mumol) in Ca(2+)-free and Ca(2+)-containing media. Dalsaxin also altered the pattern of uterine contraction stimulated by high potassium depolarization from fast-phasic to a sustained but transient plateau. It is concluded that dalsaxin causes uterine muscle contraction by mobilizing external Ca2+ through predominantly a voltage-dependent Ca2+ channel.

Bitter principles of chelonanthus chelonoides

From the whole plants of Chelonanthus cheloniodes two new bitter secoiridoid glucosides, chelonanthoside A and B (1 and 3) have been isolated as the acetates together with sweroside(5). Their structures were elucidated on the basis of chemical and extensive spectral analyses.

Investigación de glicócidos cianogenéticos en passiflora quadrangularis L. (tumbo costeño) / research of cyanogenetics glysocid in passiflora quadrangularis L (tumbo costeno)

Se ha encontrado ácido cianhídrico en passiflora quadrangularis l. verde en concentración que van de 168.48-273.6mg/kg. Se ha encontrado HCN en fruto verde en las siguientes concentraciones: (a) Epicarpo (cáscara)= 7.36-8.64mg/kg (b) mesocarpo (pulpa)=10.8-12.96mg/kg. Jugo de la excrecencia. La parte externa de la semilla = 5.4-8.64mg/kg, semilla = 16.2-20.56mg/kg. La concentración de HCN en fruto verde es mayor a la CMP que es 100 ppm. Es probable una intoxicación por cianuro en fruto verde. La concentración en fruto maduro es menor de 100ppm. no es probable una intoxicación por cianuro en fruto maduro.

Chemistry of the medicinal plants of the genus trianthema [family ficoidaceae]

The genus Trianthema belonging to the family Ficoidaceae includes Trianthema portulacastrum, T. triquetra, T. pentandra, T. govinda, T. monogyna and T. decandra as important species, which are weeds and shrubs of the tropical region. This manuscript reviews the chemical constituents like hydrocarbons, proteins, amino acids, glycosides, alkaloids, oxalic/fatty acids, of these plants. It also describes the medicinal aspects of these shrubs as well

Constituents of the aerial parts of murrubium vulgare L

Investigation of the aerial parts of Marrubium vulgare L. revealed the presence of beta-sitosterol, lupeol, marrubiin, a labdane diterpenoid lactone, vulgarin and apigenin-7-0-glucoside. These compounds were isolated and identified through chemical and spectral methods

New flavonoid glycosides from euphorbia dracunculoidea

The ethyl acetate fraction of the alcoholic extract aerial parts of Euphorbia dracunculoides afforded kaempferol and two new glycosides identified through their UV, IR, 1H-NMR, 13C-NMR, 13C-NMR [APT] COESY and HETCOR spectral data as kaempferol 3-0-beta-methyl glucouronide and kaempferol 3-0-beta-glucosyl [1-4] beta-methyl glucouronide

Açäo antimicrobiana e antitumoral de glicosídeos isolados de Ipomoea bahiensis / Antimicrobial and anti-tumoral activity of isolated glycosides of Ipomoea bahiensis

Quatro glicosídeos isolados de Ipomoea bahiensis, derivados dos ácidos 11 hidroxihexadecanóico e 11-hidroxitetradecanóico, apresentam boa atividade contra representantes de microrganismos Gram-positivos. O composto (la) também inibe significativamente o crescimento do Sarcoma 180 a doses entre 7,5 e 10,0 mg/kg