Chemical Profile and Use of the Peat as an Adsorbent for Extraction of Volatile Compounds from Leaves of Geranium (Pelargonium graveolens L' Herit).

Volatile organic compounds (VOCs) from leaves of geranium (Pelargonium graveolens L' Herit) were extracted by dynamic headspace using Porapak Q (HSD-P) as adsorbent and peat, a novel adsorbent in the extraction of plant volatiles, analyzed by gas chromatography-mass spectrometry (GC/MS) and gas chromatography-flame ionization (GC/FID), and the results were compared with those obtained by hydrodistillation (HD). The yield volatiles changed with the extraction method. HD was more efficient for extracting linalool (11.19%) and citronellyl formate (9.41%). Citronellol (28.06%), geraniol (38.26%) and 6,9-guaiadiene (9.55%) and geranyl tiglate (8.21%) were the major components identified by dynamic headspace using peat (HSD-T), while citronellol (16.88%), geraniol (13.63%), 6,9-guaiadiene (16.98%) and citronellyl formate (6.95%) were identified by dynamic headspace using Porapak Q (HSD-P). Furthermore, this work showed, for the first time, that in natura peat is useful to extract VOCs from leaves of geranium.

Bioassay-Guided Separation of Centipeda minima Using Comprehensive Linear Gradient Centrifugal Partition Chromatography.

A comprehensive linear gradient solvent system for centrifugal partition chromatography (CPC) was developed for the bioassay-guided isolation of natural compounds. The gradient solvent system consisted of three different ternary biphasic solvents types: n-hexane-acetonitrile-water (10:2:8, v/v), ethyl acetate-acetonitrile-water (10:2:8, v/v), and water-saturated n-butanol-acetonitrile-water (10:2:8, v/v). The lower phase of the n-hexane-acetonitrile-water (10:2:8, v/v) was used as the stationary phase, while its upper phase, as well as ethyl acetate-acetonitrile-water (10:2:8), and water-saturated n-butanol-acetonitrile-water (10:2:8, v/v) were pumped to generate a linear gradient elution, increasing the mobile phase polarity. We used the gradient CPC to identify antioxidant response elements (AREs), inducing compounds from Centipeda minima, using an ARE-luciferase assay in HepG2 cells, which led to the purification of the active molecules 3-methoxyquercetin and brevilin A. The developed CPC solvent systems allow the separation and isolation of compounds with a wide polarity range, allowing active molecule identification in the complex crude extract of natural products.

Special metabolites isolated from Urochloa humidicola (Poaceae).

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-ß-d-glucopyranoside and methyl quercetin-3-O-ß-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)]-ß-d-glucopyranosyl-penogenin, as well as catechin-7-O-ß-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.

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.

Actinotetraoses I-K: tetrasaccharide metabolites produced by an insect-derived actinobacteria, Amycolatopsis sp. HCa1.

An isolate of rare actinobacteria strain Amycolatopsis sp. HCa1 obtained from the gut of grasshopper produced seven different metabolites in vitro. The metabolites isolated from its mycelia cakes were characterized by NMR and MS analyses. Actinotetraose hexatiglate (or tigloside; 1) with nonreducing glucotetraose skeleton was isolated as a major constituent; three new tetrasaccharide derivatives actinotetraoses I-K (2-4, resp.) and three known actinotetraoses A-C (5-7, resp.) were also isolated.

Honaucins A-C, potent inhibitors of inflammation and bacterial quorum sensing: synthetic derivatives and structure-activity relationships.

Honaucins A-C were isolated from the cyanobacterium Leptolyngbya crossbyana which was found overgrowing corals on the Hawaiian coast. Honaucin A consists of (S)-3-hydroxy-γ-butyrolactone and 4-chlorocrotonic acid, which are connected via an ester linkage. Honaucin A and its two natural analogs exhibit potent inhibition of both bioluminescence, a quorum-sensing-dependent phenotype, in Vibrio harveyi BB120 and lipopolysaccharide-stimulated nitric oxide production in the murine macrophage cell line RAW264.7. The decrease in nitric oxide production was accompanied by a decrease in the transcripts of several proinflammatory cytokines, most dramatically interleukin-1ß. Synthesis of honaucin A, as well as a number of analogs, and subsequent evaluation in anti-inflammation and quorum-sensing inhibition bioassays revealed the essential structural features for activity in this chemical class and provided analogs with greater potency in both assays.

UV filter decomposition. A study of reactions of 4-(2-aminophenyl)-4-oxocrotonic acid with amino acids and antioxidants present in the human lens.

Deamination of UV filters, such as kynurenine (KN), in the human lens results in protein modification. Thermal reactions of the product of kynurenine deamination, 4-(2-aminophenyl)-4-oxocrotonic acid (CKA), with amino acids (histidine, lysine, methionine, tryptophan, tyrosine, cysteine) and antioxidants (ascorbate, NADH, glutathione reduced) were studied. The rate constants of the reactions under physiological conditions were measured. The rate constants of CKA addition to cysteine k(Cys)=36+/-4M(-1)s(-1) and to glutathione k(GSH)=2.1+/-0.2M(-1)s(-1) are 4-5 orders of magnitude higher than the rate constants of CKA reactions with the other amino acids and antioxidants. The Arrhenius parameters for k(Cys) and k(GSH) were determined: A(GSH)=(1.8+/-0.7)x10(5)M(-1)s(-1), E(GSH)=29.2+/-5.6kJmol(-1), A(Cys)=(2.7+/-0.9)x10(8)M(-1)s(-1), E(Cys)=40.4+/-5.7kJmol(-1). The large difference in frequency factors for k(Cys) and k(GSH) is attributed to steric hindrance, peculiar to the bulky GSH molecule.

The chemical constituents of Ligularia pleurocaulis.

AIM: To study the chemical constituents of the underground part of Ligularia pleurocaulis (Franch.) Hand-Mazz. METHODS: The dried roots and rhizomes of L. pleurocaulis were extracted with methanol. Isolation and purification were performed by silica gel column chromatography and recrystallization etc. Structures of the pure compounds were established on basis of spectral analysis. RESULTS: Twelve compounds were obtained from L. pleurocaulis, they were 6-angeloyloxy-furanoligularenone (1), 2-oxo-3-hydroxy-eremophila-1(10),3,7(11),8-tetraen-8,12-olide (2), tiglic acid (3), oleanolic acid (4), lupeol (5), beta-sitosterol (6), daucosterol (7), caffeic acid (8), emodin (9), 7-methoxy-coumarin (10), ferulic acid (11) and 4-hydroxy-2,5-dimethoxy-benzaldehyde (12). CONCLUSION: Compound 1 is a new eremophilane and compound 2 is a new natural compound. All above compounds were obtained for the first time from L. pleurocaulis.

[Isolation and structure identification of chemical constituents from Anabasis brevifolia].

AIM: To study the chemical consitituents of the n-butanol-extracts of Anabasis salsa and Various chromatographic techniques were used to the chloroform-extract of Anabasis brevifolia. METHODS: separate and purify the constituents. Their physico-chemical properties and spectral data were used to elucidate their structures. RESULTS: Five compounds were isolated and identified as 2-O-beta-D-glucopyranosyloxy-4,6-dimethoxy phenylenthanone (1), 2-O-(2)-beta-D-glucopyranosyloxy-4, 6-dimethoxy phenylenthanone (2), 3-methyl-but-2-enoic acid-[2-(4-methoxy phenyl)-ethyl]-amide (3), 5,6,7,2'-tetramethoxy isoflavonoid (4), 2'-hydroxy-5,6,7-trimethoxyisoflavonoid (5). CONCLUSION: Compounds 2, 3, and 5 are new compounds. And the others were isolated from Anabasis L. for the first time.

Crotonic acid as a bioactive factor in carrot seeds (Daucus carota L.).

Water extracts from the carrot seed (Daucus carota L.) var. Perfekcja exhibit plant growth inhibitory properties against cress, cucumber, onion and carrot in a dose-dependant manner. This property results from the action of low-and high-molecular components of the extract. The low-molecular component was identified as crotonic acid ((E)-2-butenoic acid). Its presence was also confirmed in other late varieties of carrot. The determined strong herbicidal properties of crotonic acid and its availability after release to soil combined with its high level in seeds suggest that it might be considered as an allelopathic and autotoxic factor in the seeds.

[Constituents of Liguliria vellerea (Franch.) Hand-Mazz].

OBJECTIVE: To study the chemical constituents of Ligularia vellerea. METHOD: The compounds were isolated by column chromatography, and the structures were identified by NMR spectral data and other methods. RESULT AND CONCLUSION: Seven compounds were isolated and identified as 4-hydroxyacetophenone, 8 alpha-hydroxy-7(11)-eremophilen-12, 8 beta-olide, umbelliferone, tiglic acid, 6 beta-hydroxy-7(11)-eremophilen-12, 8 alpha-olide, daucosterin, beta-sitosterol and stigmasterol. All the compounds were isolated for the first time from this plant.

Structure of actinotetraose hexatiglate, a unique glucotetraose from an actinomycete bacterium.

An Actinomycete strain A499 belonging to the genera Amycolatopsis or Amycolata isolated from a Western Australian soil sample produced the cyclic decapeptide antibiotic quinaldopeptin (1), together with the actinotetraose hexatiglate (2), the hexa-ester of a novel non-reducing glucotetraose.

Reversed-phase high-performance liquid chromatographic separation of steroids with the beta-crotonate side chain.

An isocratic high-performance liquid chromatographic separation of some ethyl 3-stereoidyl crotonates [ethyl-24-nor-20(22)-cholen-23-oate derivatives] was developed. The separations were achieved by reversed-phase chromatography (Separon Si C18) using methanol, methanol-water, methanol-0.1 M formic acid and ethanol-0.01 M aqueous phosphoric acid mixtures as mobile phases. The steroidal crotonates were detected at 230 and 240 nm.

The structure of a glyoxalase I inhibitor and its chemical reactivity with SH-compounds.

The structure of a glyoxalase I inhibitor (I), isolated from a cultured broth of Streptomyces griseosporeus, was found to be 2-crotonyloxymethyl-4,5,6-trihydroxy-cyclohex-2-enone by chemical studies. Stereochemistry and absolute configuration were determined to be 4R, 5R and 6R by X-ray crystallographic analysis of a bromine-containing crystalline derivative. The crotonyloxy group of I shows a surprising proclivity to be displaced by SH-compounds. This property is shown to be the basis for its biological activity.