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Liquid chromatography/mass spectrometry (particle beam interface, electron impact ionization), fast‐atom bombardment mass spectrometry (FAB‐MS) (negative‐ion mode) and FAB‐tandem mass spectrometry (MS/MS) techniques were applied for the rapid detection/characterization of low‐to‐intermediate molecular weight polyphenol constituents of Krameria triandraroots with radical scavenging activity, this determined in a well established membrane model of lipid peroxidation (phosphatidylcholine liposomes). LC/MS analysis of the more lipophilic fractions of the drug (antioxidant activity: IC50, the concentration which gives 50% inhibition, 5.8 μg/mL petrol extract; IC503.7 μg/mL chloroform extract) evidences at least 9 components belonging to the class of lignans; FAB‐MS/MS analysis of the butylacetate extract (IC50= 0.23μg/mL) caffeoyl esters, catechin‐glucosides, dimeric procyanidines and their corresponding phenylpropanoyd derivatives. © 1997 John Wiley & Sons, Ltd.

Fast‐atom bombardment mass spectrometry (FAB‐MS, both in the positive‐and negative‐ion modes) and gas chromatography/mass spectrometry (GC/MS) were applied for the rapid identification of the main ingredients of two widely employed cosmetic products, a mascara and a semipermanent hair dye. FAB‐MS, on the untreated product (hair dye) or on a crude methanol extract (mascara) gives an unequivocal fingerprint of involatile constituents, i.e.surfactants, anionic (cetyl/stearyl soaps) in mascara and cationic (polyethoxylated oleyl/linoleyl/ricinoleyl‐methyl ammonium chloride) in the hair dye. GC/MS (n‐hexane and chloroform extracts), detects hydrocarbons, volatile silicon compounds, perfume components, preservatives and antioxidants in mascara and fatty acids (C8–C18), dye solvents and 4 colouring agents: 2‐amino‐5‐nitrophenol, HC Yellow 2 (N‐2‐hydroxyethyl‐o‐nitroaniline); O‐(2‐hydroxyethyl)‐4‐amino‐3‐nitrophenol and HC Red3, N‐(2‐hydroxyethyl)‐2‐nitro‐p‐phenylendiamine in the hair dye. These results demonstrate that the combined FAB‐MS and GC/MS approaches, enabling a complete picture of the constituents of the cosmetic matrix, provide an invaluable analytical tool for the quality control of cosmetics, a subject that has been rather neglected to date. © 1997 John Wiley & Sons, Ltd.

The antioxidant activity of nimesulide and its main metabolites, 4′-hydroxynimesulide (M1) and 2-(4′-hydroxyphenoxy)-4-N-acetylamino-methansulfonanilide (M2), was investigated using 2 in vitromodels: NADPH-supported lipid peroxidation in rat liver microsomes (marker MDA formation) and xanthine/xanthine oxidase, iron-promoted depolymerisation of hyaluronic acid, determined by gel permeation Chromatographic analysis (marker molecular weight distribution). In the lipid peroxidation model, all the compounds inhibited MDA formation in a concentrationdependent manner, although with different potencies; the maximum scavenging effect was observed for M1 [50% inhibitory concentration (IC50) = 30 μmol/L; M2 IC50= 0.5 mmol/L; nimesulide = 0.8 mmol/L]. Nimesulide was more active than its metabolites in preventing OH·-induced depolymerisation of hyaluronic acid, with a 50% effective concentration of approximately 230 μmol/L, which was fairly comparable to that of tenoxicam. This protective effect was due to the OH·-entrapping capacity of the drug, which, in the Fenton-driven model, is easily converted, via OH· attack, to M1 and putatively to 2-hydroxy-4-nitro-methansulfonanilide.

Liquid chromatography/ion trap mass spectrometry with an atmospheric pressure chemical ionization (APCI) interface in the negative‐ion mode, using collision‐induced dissociation (CID) of precursor ions in parallel with UV‐diode‐array detection (DAD), was applied to the characterization in crude extracts of the water‐soluble antioxidant phenolics from Maté leaves (Ilex paraguayensis). APCI gives unequivocal information about both the molecular mass of these compounds and some indications about their structure, which were confirmed by the UV‐DAD fingerprints and by the diagnostic CID patterns. This allowed the identification of 10 constituents, including the 3 naturally occurring isomers of caffeoylquinic acid (CGA), namely neo‐chlorogenic acid, chlorogenic acid and crypto‐chlorogenic acid, as well as 3 isomeric dicaffeoyl quinic acids, rutin (quercetin‐3‐rutinoside), a diglycosyl derivative of luteolin, and 2 isomeric caffeoyl‐glucosides. The aqueous extract of Maté, quantitatively analyzed for polyphenol and CGA content (HPLC), was tested for antioxidant activity in both a cell‐free system (quenching of the stable free radical DPPH, 2,2‐diphenyl‐1‐picryl‐hydrazyl) and in a model membrane system (phosphatidylcholine liposomes). The results demonstrate that the extract is a strong radical scavenger, considerably more potent than the prototype chlorogenic acid, and this indicates a cooperative antioxidant interaction among its polyphenol components. © 1998 John Wiley & Sons, Ltd.

An isolated rabbit heart Langendorff preparation paced electrically was used to evaluate the effects of a highly purified, high molecular weight fraction of oligomeric procyanidines isolated from VITIS VINIFERA seeds on myocardial reperfusion injury after 40 minutes of low flow (1 ml/min) ischemia. Infusion of the heart with 100 or 200 g/ml procyanidines dose-dependently reduced ventricular contracture during ischemia (LVEDP values decreased by 28% and 51%), decreased coronary perfusion pressure (CPP), improved cardiac mechanical performance upon reperfusion, increased the release of 6-keto-PGF 1? into the perfusate in both the pre-ischemic and the reperfusion periods (by 68% at 200 g/ml), and suppressed rhythm irregularity. This antiarrhythmogenic action was confirmed in a more severe model of ischemia (flow rate 0.2 ml/min). The cardioprotective agent allopurinol infused at 20 g/ml had effects on the contractility and on the release of 6-keto-PGF 1? comparable to those of 200 g/ml procyanidines. The results of the second part of this study show that procyanidines are potent scavengers of several reactive oxygen species involved in the ischemia/reperfusion damage: the superoxide anion (IC 50 = 5.64 M; rate constant K = 7.55 10 5M -1 s -1, determined by the phenazine methosulfate/NADH method); the hydroxyl radical (IC 50 = 28 M; rate constant K = 1.2 10 12M -1 s -1 determined by the electron spin resonance spectroscopy); peroxyl radicals (IC 50 = 0.025 M and 0.35 M, determined using two different lipid substrates, phosphatidylcholine liposomes and methyl linoleate micelles by UV spectroscopy at 233 nm). Finally, procyanidines interact with Fe 2+ and Cu 2+ ions (the catalysts of HO radicals production) giving rise to strong complexes, with stability constants (log K) ranging from 9.35 to ? 9.