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trans-Caftaric acid is the most abundant nonflavonoid phenolic compound in grapes and wines. It occurs in chicory and is one of the bioactive components of Echinacea purpurea. In order to fill the gap of knowledge about its bioavailability in mammals, we investigated its absorption, tissue distribution, and metabolism in rats. Assuming that the stomach is a relevant site of absorption of dietary polyphenols, a solution of trans-caftaric acid was maintained in the ligated stomach of anaesthetized rats for 20 min. Intact trans-caftaric acid was detected in rat plasma at both 10 and 20 min (293 +/- 45 and 334 +/- 49 ng/mL, respectively), along with its O-methylated derivative trans-fertaric acid, whose concentration rose over time (from 92 +/- 12 to 185 +/- 24 ng/mL). At 20 min, both trans-caftaric acid and trans-fertaric acid were detected in the kidney (443 +/- 78 and 2506 +/- 514 ng/g, respectively) but not in the liver. Only trans-fertaric acid was found in the urine (33.3 +/- 12.8 microg/mL). In some rats, trans-caftaric acid was detected in the brain (180 +/- 20 ng/g).

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The composition of the volatile fraction of Polygonum bistorta L. (also known as bistort or snakeroot) was investigated. Fresh aerial parts of this plant species were collected in the Western Italian Alps during the summer at three different phenological stages, namely vegetative, flowering, and fruiting, and steam-distilled in a Clevenger-type apparatus. The oils accounted for 0.004 to 0.010% of the fresh plant material, and their compositions were determined by GC/FID and GC/MS. The composition of the oils during the vegetative period varied both in quantity and quality; several classes of compounds were found with a predominance of alcohols in the vegetative phase, terpenes and linear-chained saturated hydrocarbons in the flowering phase, while saturated aliphatic acids and their methyl esters were predominant in fruiting phase. The most abundant compounds were 3-methylbut-3-en-1-ol in the vegetative phase, linalool in the flowering phase, and dodecanoic acid and its methyl ester in the fruiting phase. The obtained essential oils were then tested against two major bee pathogens, i.e., Paenibacillus larvae and Melissococcus plutonius, and against a reference bacterial species, Bacillus subtilis. Data were compared to those obtained with reference standards used against those pathogens such as the essential oils obtained from leaves and bark of Cinnamomum zeylanicum (cinnamon), and the antibiotic oxytetracyclin.

The composition of the volatile fraction of Trifolium pratense L. ssp. nivale (Sieber) Asch. et Gr. from the southwestern Alps was investigated. Fresh aerial parts were collected in the summer at three different growth stages, namely vegetative, flowering and fruiting. The oils obtained by steam-distillation accounted for 0.006 to 0.011% of the fresh plant material and their composition was determined by GC/FID and GC/MS. Several classes of compounds were found, with a predominance of alcohols in all phases, followed by aldehydes, hydrocarbons, terpenes, phenolics, ketones, acids and esters. The oil composition varied both in quantity and quality; the most abundant compounds were oct-1-en-3-ol and phenylacetaldehyde in the vegetative and flowering phases, and phenylacetaldehyde and 2-phenylethanol in the fruiting phase. The essential oils obtained were tested for activity against two major bee pests, i.e. Paenibacillus larvae and Melissococcus plutonius, and against a reference bacterial species, Bacillus subtilis.

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The volatile fraction from vegetative aerial parts and inflorescences of Nigritella nigra (L.) Rchb. F. (Orchidaceae) collected in Val Varrone (Orobie Alps, Italy) was isolated by steam distillation and analysed by gas chromatography/ flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS). The oil yield was 0.2% and 0.9% (weight/fresh weight bases) for leaves and inflorescences, respectively. Several classes of compounds were detected, including alcohols, aldehydes, hydrocarbons, acids and terpenes. Volatiles from inflorescences were characterized by higher concentrations of alcohols, of which benzyl alcohol (28.9% of the total oil, 246.8 lg/g) and 2-phenylethanol (10.4%, 89.1 lg/g) were the most represented. Leaves were instead characterized by phenylacetaldehyde as the major constituent, quoted as 14.7% (24.0 lg/g) of the total volatiles, followed by linear chain saturated hydrocarbons, a class of compounds representing 40.1% (65.6 lg/g) of the total oil. The presence of vanillin, revealed in inflorescences only and quantified in this plant organ as 0.8% (6.5 lg/g) of the total volatiles, seems to be related to the typical chocolate-like fragrance characteristic of the flowers of this species.

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