Post-column sodiation to enhance the detection of polyacetylene glycosides in LC-DAD-MS analyses: an example from Bidens gardneri (Asteraceae).

The use of liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) in dereplication studies of medicinal plants is a common strategy, but the analyses of polyacetylenes by LC-ESI-MS are little explored and require huge efforts, especially if there are low concentrations in the extracts. A post-column sodiation strategy was successfully applied to enhance the detection of polyacetylene glycosides. Their molecular formulae were proposed by HRESI, whereas the polyacetylene chromophores were determined by UV data.

Flavanone glycosides from Bidens gardneri Bak. (Asteraceae).

LC-DAD-MS/MS analysis of the Brazilian medicinal plant Bidens gardneri Bak. (Asteraceae) results in identification of eleven phenolic compounds. HRESIMS, MS/MS and UV data analyses, with phytochemicals isolation guided by MS data, results in flavanones-(-)-4'-methoxy-7-O-β-D-glucopyranosyl-8,3'-dihydroxyflavanone; (-)-7-O-(6″-E-p-coumaroyl)-β-D-glucopyranosyl-8,3',4'-trihydroxyflavanone; and (-)-4'-methoxy-7-O-(6″-acetyl)-β-D-glucopyranosyl-8,3'-dihydroxyflavanone being identified-together with four known compounds.

Biotransformation of ent-pimaradienoic acid by cell cultures of Aspergillus niger.

Microbial transformation stands out among the many possible semi-synthetic strategies employed to increase the variety of chemical structures that can be applied in the search for novel bioactive compounds. In this paper we obtained ent-pimaradienoic acid (1, PA, ent-pimara-8(14),15-dien-19-oic acid) derivatives by fungal biotransformation using Aspergillus niger strains. To assess the ability of such compounds to inhibit vascular smooth muscle contraction, we also investigated their spasmolytic effect, along with another five PA derivatives previously obtained in our laboratory, on aortic rings isolated from male Wistar rats.

Fungal transformation and schistosomicidal effects of pimaradienoic acid.

The schistosomicidal effects of pimaradienoic acid (PA) and two derivatives, obtained by fungal transformation in the presence of Aspergillus ochraceus, were investigated. PA was the only compound with antischistosomal activity among the three diterpenes studied, with the ability to significantly reduce the viability of the parasites at concentrations ranging from 25 to 100 μM. PA also promoted morphological alterations of the tegument of Schistosoma mansoni, separated all the worm couples, and affected the production and development of eggs.

Anticariogenic properties of ent-pimarane diterpenes obtained by microbial transformation.

In the present work, the anticariogenic activities of three pimarane-type diterpenes obtained by fungal biotransformation were investigated. Among these metabolites, ent-8(14),15-pimaradien-19-ol was the most active compound, displaying very promising MIC values (ranging from 1.5 to 4.

DOSY NMR applied to analysis of flavonoid glycosides from Bidens sulphurea.

2D DOSY 1H NMR has proved to be a useful technique in the identification of the molecular skeleton of the four major compounds of ethyl acetate extract of aerial parts of Bidens sulphurea (Asteraceae). The combination of this technique with HPLC, mass spectrometry and other NMR techniques enabled the identification of four flavonoid glycosides: quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-beta-D-glycopyranoside, quercetin-3-O-alpha-L-arabinofuranoside and quercetin-3-O-beta-D-rhamnopyranoside.

Antimicrobial activity of kaurane diterpenes against oral pathogens.

Two kaurane diterpenes, ent-kaur-16(17)-en-19-oic acid (KA) and 15-beta-isovaleryloxy-ent-kaur-16(17)-en-19-oic acid (KA-Ival), isolated from Aspilia foliacea, and the methyl ester derivative of KA (KA-Me) were evaluated against oral pathogens. KA was the most active compound, with MIC values of 10 microg mL(-1) against the following microorganisms: Streptococcus sobrinus, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, and Lactobacillus casei. However, KA did not show significant activity against Streptococcus salivarius and Enterococcus faecalis, with MIC values equal to 100 and 200 microg mL(-1), respectively.

Chromanones with leishmanicidal activity from Calea uniflora.

The dichloromethane extract of Calea uniflora afforded a mixture of two novel chromanones, uniflorol-A (1) and uniflorol-B (2), and one known chromanone, 2,2-dimethyl-6-(1-hydroxyethyl)-chroman-4-one (3). The structures of these compounds were determined by spectroscopic methods. Biological activity of the compounds against Leishmania major promastigotes was evaluated.

A new 5-deoxyflavone glycoside from the aerial parts of Calea clausseniana.

A new 5-deoxyflavone glycoside, identified as 7-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl)-3',4',7-trihydroxyflavone (1), was isolated from the aerial parts of Calea clausseniana. Its structure was determined by spectral analysis.

Transdermal delivery of ketoprofen: the influence of drug-dioleylphosphatidylcholine interactions.

Purpose: Considering that most inflammatory diseases occur locally and near the body surface, transdermal delivery of non-steroidal anti-inflammatory drugs (NSAIDs) may be an interesting strategy for delivering these drugs directly to the diseased site. To optimize ketoprofen (KP) transdermal delivery we investigated the influence of dioleylphosphatidylcholine (DOPC) on skin permeation.

Materials And Methods: The formulations studied were: i) a physical mixture of KP and DOPC and ii) DOPC and KP complex, in a molar ratio of 1:3, obtained by dissolution of the components in chloroform followed by drying under a N2 atmosphere.

Pharmacological comparison of the vasorelaxant action displayed by kaurenoic acid and pimaradienoic acid.

The vascular effects of two natural occurring diterpenes from the kaurane and pimarane classes were compared. The diterpenes ent-kaur-16-en-19-oic acid (kaurenoic acid; KA) and ent-pimara-8(14), 15-dien-19-oic acid (pimaradienoic acid; PA) were tested for their antispasmodic activity on isolated rat aorta. Vascular reactivity experiments, using standard muscle bath procedures, showed that KA and PA (both at 50 and 100 microM) inhibited phenylephrine and KCl-induced contraction in both endothelium-intact and endothelium-denuded rat aortic rings, with PA being more effective than KA.

Role of the carboxylic group in the antispasmodic and vasorelaxant action displayed by kaurenoic acid.

The present work describes the investigation of the role of the carboxylic group in the structure-activity relationship of the diterpene ent-kaur-16-en-19-oic acid (kaurenoic acid, KA) in inhibiting rat aorta contraction. For this purpose the methylation of the C-19 carboxyl group of KA was carried out. The effects of the obtained ent-methyl-kaur-16-en-19-oate (KAMe) were compared with those induced by KA.

Antimicrobial activity of extracts and some compounds from Calea platylepis.

The antimicrobial activity of dichloromethane extracts (leaves, flowers and underground parts) and some compounds isolated from Calea platylepis were evaluated by the well diffusion method.

Analysis of the mechanisms underlying the vasorelaxant action of kaurenoic acid in the isolated rat aorta.

The present work describes the mechanisms involved in the vasorelaxant effect of the diterpene ent-kaur-16-en-19-oic acid (kaurenoic acid). Kaurenoic acid (10, 50 and 100 microM) concentration-dependently inhibited phenylephrine and KCl-induced contraction in either endothelium-intact or -denuded rat aortic rings. Kaurenoic acid also reduced CaCl(2)-induced contraction in Ca(2+)-free solution containing KCl (30 mM).

Trypanocidal and antifungal activities of p-hydroxyacetophenone derivatives from Calea uniflora (Heliantheae, Asteraceae).

The dichloromethane extract of underground parts of Calea uniflora (Heliantheae, Asteraceae) exhibited trypanocidal and antifungal activities. Four p-hydroxyacetophenone derivatives were isolated as the main compounds: 2-senecioyl-4-(hydroxyethyl)-phenol (1), 2-senecioyl-4-(angeloyloxy-ethyl)-phenol (2), and two new derivatives, 2-senecioyl-4-(methoxyethyl)-phenol (3) and 2-senecioyl-4-(pentadecanoyloxyethyl)-phenol (4). 1 and 4 were active towards Trypanosoma cruzi trypomastigotes, reducing their number by 70 and 71% at 500 microg x mL(-1), whereas 2 and 3 were inactive.