Phytochemical and antioxidant analysis of eight Hypericum taxa from Central Italy.

Eight taxa of the Hypericum spp. growing in Central Italy (Appennino Umbro-Marchigiano) were analyzed by HPLC-DAD for constituents quantitation, for antioxidant and free radical scavenging activities. H. perforatum subsp. veronense was the richest in phenolic compounds and hyperforin was detected for the first time in H. hircinum subsp. majus. Significant values of antioxidant activity were found in the investigated Hypericum taxa.

Searching for cyclazosin analogues as alpha(1B)-adrenoceptor antagonists.

A series of quinazoline derivatives, 2-20, structurally related to the racemic alpha(1)-adrenoceptor antagonist cyclazosin (1), were synthesized and evaluated for their functional antagonism at alpha(1)- and alpha(2)-adrenoceptors and for their binding affinity at human cloned alpha(1a)-, alpha(1b)- and alpha(1d)-adrenoceptor subtypes. They displayed, like 1, preferential antagonism and selectivity for alpha(1) versus alpha(2)-adrenoceptors. Compounds 10, 13, and 18 showed high potency at alpha(1)-adrenoceptors similar to that of 1 (pK(B) values 8.47-8.89 versus 8.67), whereas 13 and 15 were endowed with the highest alpha(1)-adrenoceptor selectivity, only 3- to 4-fold lower than that of 1. In binding experiments, all of the compounds displayed an affinity practically similar to that found for 1, with the exception of 19 and 20 that were definitely less potent. The s-triazine analogue 18 was the most potent of the series with pK(i) values of 10.15 (alpha(1a)), 10.22 (alpha(1b)) and 10.40 (alpha(1d)), resulting 77-fold more potent than 1 at alpha(1a)-adrenoceptors. In addition, the majority of compounds, like prototype 1, showed the same trend of preferential affinity for alpha(1d)- and alpha(1b)-adrenoceptors that alpha(1a)-subtype. In conclusion, we identified compounds 2-5, 10, 12 and 13, bearing either an aliphatic- or an arylalkyl- or aryloxyalkyl-acyl function, with an interesting subtype-selectivity profile, which makes them suitable candidates for their resolution as enantiomers structurally related to (+)-cyclazosin.

Simultaneous determination of eight underivatised biogenic amines in fish by solid phase extraction and liquid chromatography-tandem mass spectrometry.

Biogenic amines on fish tissue are formed as a result of bacterial contamination and spoilage during storage. A new method based on liquid chromatography (LC) and tandem mass spectrometry (MS/MS) using a triple quadrupole (QqQ) analyser was developed for the analysis of eight biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermine, spermidine, tyramine and tryptamine) in fish tissues. Sample preparation was performed by extraction with trichloroacetic acid 5% and solid phase extraction clean up with STRATA X cartridge. The MS/MS method was validated and compared with a method based on the analysis of dansyl derivatives by LC and fluorescence detector (FD). MS/MS achieved higher sensitivity (from 0.02mgkg(-1) for spermidine and phenylethylamine to 0.2mgkg(-1) for spermine) when compared to FD (from 1mgkg(-1) for putrescine and tyramine to 4mgkg(-1) for histamine); MS/MS method showed higher precision too, with intraday relative standard deviations (RSDs) from 1% to 4% with respect to those obtained with FD method (from 3% to 17%). Recovery study was conducted at two different fortification levels and the average ranged from 71% to 93% for all of the studied compounds with RSDs lower than 18%. Matrix-matched standards were used to counteract matrix effect observed in MS/MS determination. The applicability of the method was demonstrated by the analysis of biogenic amines in fish obtained from commercials of Valencia.

HPLC quantification of coumarin in bastard balm (Melittis melissophyllum L., Lamiaceae).

Coumarin occurs in many plants used as flavoring and is known to possess hepatotoxic effects. Despite in the EFSA 'Compendium of botanicals containing toxic substances' coumarin is reported to be present in Melittis melissophyllum (bastard balm), a plant traditionally used as beverage in Italy and Serbia, to the best of our knowledge quantitative data has never been reported. Thus, the amount of coumarin in bastard balm leaves and its variation during the annual phenological cycle were determined. The subsp. melissophyllum resulted to contain high levels of coumarin (14,392 mg/kg), mainly in the early stages of the plant cycle, suggesting prudence in its use as beverage. Furthermore, coumarin was found to be useful as marker compound to differentiate the bastard balm subspecies occurring in Italy, since the subsp. albida contained a much lower content of this molecule (19-34 mg/kg).

Levels of polychlorinated biphenyls in fish and shellfish from the Adriatic Sea.

Levels of 18 polychlorinated biphenyl (PCB) congeners were determined by gas chromatography-mass spectrometry (GC-MS) in some marine species, living both in the coastal area and in deeper seawater. In some species analysis was performed separately in edible parts (fillets) and in viscera. The existence and degree of bioaccumulation was assessed studying individual species of very different size, with the smaller being younger. Furthermore, with a multivariate statistical analysis, a correlation between PCB congeners and the feeding habits and habitat of the fish was demonstrated. The results show that fat from edible parts (fish fillets) had total PCB levels in the range 22.6-601.9 µg kg⁻¹ (with 601.9 µg kg⁻¹ in anchovies), while fat from viscera showed much higher concentrations (407.3-916.6 µg kg⁻¹). Bioaccumulation was confirmed, comparing PCB levels between younger and older individual hake, squid, and horned octopus. The total PCB concentration ratio (older/younger individuals) ranges from 2.11 (squid = 292.1/137.8 µg kg⁻¹) to 3.46 (hake = 546.0/158.0 µg kg⁻¹).