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S De Stefano

Publications and source records attributed to S De Stefano.

12 recordsLinked to original sources
PubMed2004

Antagonism against Rhizoctonia solani and fungitoxic metabolite production by some Penicillium isolates.

A number of Penicillium isolates were recovered in association to Rhizoctonia solani strains pathogenic on tobacco and from soil on plates pre-colonized by the pathogen itself. Their antagonism toward R. solani AG-2-1 was evaluated in dual cultures in vitro. Inhibition of growth was evident to some extent in most pairings, while hyphal interactions referable to mycoparasitic relationships were not observed. However, the occurrence of plasmolysis and/or vacuolisation and the induction of monilioid cells were indicative of the release of bioactive compounds. Therefore, production of fungitoxic metabolites was tested by adding concentrated culture filtrates of each Penicillium isolate to the growth medium of R. solani. Complete and lasting inhibition was incited by culture filtrates of some isolates belonging to P. brevicompactum, P. expansum, and P. pinophilum. Three purified compounds, respectively mycophenolic acid, patulin and 3-O-methylfunicone, which were extracted from culture filtrates, were able to inhibit R. solani in vitro. Their production was also detected in dual cultures of the same Penicillium strains with R. solani prepared in sterilized soil and when the Penicillium strains were cultured directly on R. solani mycelium harvested from liquid cultures. The possible role of such metabolites in antagonism of the above-mentioned Penicillium species against R. solani is discussed.

Antibiosis↗
PubMed1991

Kelletinin I and kelletinin A from the marine mollusc Buccinulum corneum are inhibitors of eukaryotic DNA polymerase alpha.

The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropod Buccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerases alpha and beta, DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse and E. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymerase alpha. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.

Animals↗
PubMed1988

Central nervous system activity of terpenoids from marine sponge.

Some terpenoids extracted from marine sponge: triacetylated disidein, 2-tetraprenyl benzoquinol and 4 hydroxy-3-tetraprenylbenzoic acid 2-polyprenyl benzoquinols, avarol and furospongin-1 were tested by multidimensional Irwin screening and with some tests for analgesic and muscle relaxant activity. The three prenylhydroquinols derivatives and avarol show a good analgesic activity and low toxicity.

Analgesics↗
PubMedDate not supplied

[Effect of sulphurous Bioglea on psoriasis].

OBJECTIVE: The efficacy of biological sulphurous Bioglee on psoriasis was investigated using an organic matrix derived from the metabolism of microflora growing in shallow hyper thermal waters possessing high sulphur concentrations and in thermal mud at Guardia Piemontese-Acquappesa (CS). Such a matrix forms part of the "Sulphuretum" ecological matrix which is dominated by cyanobacteria and sulfobacteria. The effect of this matrix on psoriasis was evaluated through the typical symptoms such as desquamation, cutaneous erythema and itching. METHODS: The study was carried out on 20 patients wich gave informed consent, suffering from psoriasis. Image analysis was used to monitor the intensity of psoriasic lesions prior to and at the conclusion of the therapy which consisted of topical applications of the thermal matrices twice a day for 12 days. RESULTS: Image analysis illustrated a reduction in the intensity of psoriasic lesions at the conclusion of the therapy with significant reductions in desquamation, erythema and itching. CONCLUSIONS: The anti-psoriasic action of the thermal matrix used in this study may be attributable to the substances such as carotene, hydro and lipo-soluble vitamins and naturally occuring phytosterols. These substances may not only be anti-inflammatory but may also work synergistically with the mineral components of the thermal matrix to attenuate the symptoms of psoriasis.

Adult↗