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Two new lignan derivatives (1 and 2), along with the known scopoletin (3), methyl caffeate (4), falcarindiol (5), 3,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic methyl ester, chlorogenic acid, p-hydroxyphenylethyl-trans-ferulate, and vanillin, were isolated from extracts of the roots of Chaerophyllum hirsutum. Structure elucidation of the new compounds was carried out by 1D and 2D NMR experiments and by HRMS analysis. Several of the isolated compounds were tested for their cytotoxic activity against the HL-60, HT-1080, LoVo, and LoVo/Doxo cell lines.

Bioactivity-guided fractionation of Polygala alpestris L. (Rchb.) extracts led to the identification of two new xanthones, 1,3,7-trihydroxy-2,6-dimethoxyxanthone (1) and 2,3-methylenedioxy-4,7-dihydroxyxanthone (2). In addition five known compounds 3,4-dimethoxy-1,7-dihydroxyxanthone (3), 1,3-dihydroxy-7-methoxyxanthone (4), 1,7-dihydroxy-2,3-dimethoxyxanthone (5), 3',6-O-disinapoyl sucrose (6) and 3',5'-dimethoxybiphenyl-4-olo (7) were isolated. The structures of the isolated compounds were established by means of high resolution mass spectrometry, mono- and bi-dimensional NMR spectroscopy. All isolated compounds were tested for cytotoxic activity against three tumor cell lines (LoVo, HL-60, K 562).

The biologically active naphthodianthrones hypericin and pseudohypericin were detected by electrospray ionization mass spectrometry (ESI-MS/MS) in microsamples from the sepals of Hypericum elodes (Hypericaceae) containing the so-called "red glands", i.e. stipitate glands with red-coloured heads. The occurrence of hypericins in the red glands of H. elodes supports the taxonomic position of the section Elodes within the genus Hypericum and provides evidence that the ability of carrying out the biosynthetic pathway leading to the naphthodianthrone compounds, rather than the absolute amounts produced, should be regarded as a chemical marker of the phylogenetically more advanced sections of genus Hypericum. The biologically active phloroglucinol derivatives hyperforin and adhyperforin, so far found only in H. perforatum, were also detected and evidence for their localization in the sepal secretory canals with large lumen, is given.

A stable cell suspension line of Catharanthus roseus producing anthocyanin was obtained. In this strain it was found that approximately 30% of cells regularly accumulated these metabolites and that anthocyanin accumulation occurred between the second half of log phase and the stationary phase of the culture growth cycle. The anthocyanins in the suspension cultures were compared with those biosynthetized in the flowers both of regenerated by somatic embryogenesis and field-grown plants. Six anthocyanins were identified in all the examined samples, three 3-O-glucosides and three 3-O-(6-O-p-coumaroyl) glucosides of petunidin, malvidin and hirsutidin. The hirsutidin coumaroyl glucoside has not been reported previously, and was predominat in all samples. The anthocyanin relative content was similar for cell suspensions and flowers from regenerated plants but different from field-grown plant flowers; instead, the total content was almost the same for the two flower types and higher compared to suspension culture content.

A widespread occurrence of melatonin in plant kingdom has been reported. The circadian rhythm in the level of melatonin observed in both unicellular algae and higher plants, suggests a role in regulation of photoperiodic and rhythmic phenomena, i.e. a similar function for melatonin in both plants and animals. Evidence has been obtained for a role of melatonin in plant morphogenesis, but more research is needed to ascertain other suggested physiological roles in higher plants (seed dormancy regulation, radical scavenger activity, interaction with calmodulin) as well the ecological significance of the high melatonin levels recorded in alpine plants. Setting-up more reliable analytical methods for melatonin detection and quantification is a basic requirement to get more insight into melatonin roles in plant physiology and ecology.

To search for antitumor agents from plants, we studied Polygala vulgaris since cytotoxic lignans are known to occur in some Polygala species. Preliminary data on plant petrol ether, chloroform, and methanol extracts from the roots and aerial parts, showed in vitro cytotoxic activity against the solid tumor LoVo cell line. Fractionation of the active extracts led to the isolation of three new compounds, a derivative of aucuparine and two xanthones, as well as a known methylsinapate. All compounds were tested for in vitro cytotoxic activity using two cell lines, LoVo and its strain, which express resistance to common antitumor agents.

A new arylnaphthalene lignan glycoside, patavine (1), together with five known lignans, justicidin B (2), diphyllin (3), tuberculatin (4), majidine (5), and arabelline (6) were isolated from shoot cultures of Haplophyllum patavinum. The structure of the new compound was elucidated by extensive one-dimensional (1D) and two-dimensional (2D) NMR experiments and mass spectrometry. The cytotoxicity of compounds 1, and 3-6 against LoVo human colon carcinoma cells was investigated.

A protocol for shoot induction from callus of Haplophyllum patavinum was established. Two known furoquinoline (skimmianine and haplopine), and three quinolone (edulinine, ribalinine and isoplatydesmine) alkaloids were isolated for the first time from plant material, callus and shoot cultures of this species. The structures of these compounds have been characterised on the basis of spectroscopic evidence.

Furocoumarin distribution patterns in the fruits and seeds ofPsoralea macrostachya andP. onobrychis were investigated. Both species contain the linear furocoumarin psoralen and its angular isomer, angelicin. In the monospermous indehiscent fruit ofP. macrostachya, furocoumarins occur in the pericarp and all seed parts. InP. onobrychis, the pericarp of which is easily detached at ripeness, no furocoumarins were found in the pericarp tissues and only traces occur in the embryo axis; cotyledons are the preferential accumulation site. The within-fruit and -seed furocoumarin variations associated with the developmental stages of fruit were followed inP. onobrychis, in view of changes in the defensive value of the pericarp before and after ripening. Rapid furocoumarin biosynthesis after fertilization was observed in both pericarp and seed; ripening is associated with furocoumarin decrease in the seed and complete disappearance in the pericarp tissues. Such findings are consistent with the chemical defense role of these substances. The cooccurrence of linear and angular isomers seems to be a chemical marker of the genusPsoralea: the biosynthetic pathway leading to the angular isomer as an evolutionary response to selective pressure from herbivore insects is suggested.

More than 100 antileukodermic recipes, involving about 80 plant species used in Italy through the centuries, were collected from Renaissance texts, folk medicine and contemporary herbal usage. The possible efficacy of the recorded plants in stimulating physiological skin pigmentation is discussed in the light of present phytochemical and pharmacological knowledge. Many plants contain erythemogenic substances, some of which (furocoumarins, hypericin) induce light-mediated hypermelanogenesis. Other plants can colour the epidermal keratin (tannins, anthraquinones) or the subcutaneous fat depot (beta-carotene). The usefulness of other plants remains obscure.

The utilization of more than 90 plant species as folk external remedies to treat rheumatic and arthritic diseases is reported, and their possible effectiveness is discussed according to present phytochemical and pharmacological knowledge. Some of the plant species used exhibit skin-irritant properties (protoanemonin, isothiocyanate or allicine yielding plants and species containing capsaicin, oleoresins, volatile oils, resinous principles, alkaloids). The effectiveness of other herbal remedies depends on their content of salicyl derivatives. A considerable number of the plant species utilized contain chemical products (triterpenoid or steroid compounds, alkaloids) for which anti-inflammatory properties have been demonstrated.