Polar and antioxidant fraction of Plumbago europaea L., a spontaneous plant of Sardinia.

Secondary metabolite isolation and analysis of Plumbago europaea L. (Plumbaginaceae) is the aim of this work, which is included in a project of our groups on spontaneous and endemic Sardinian species. Plumbago europaea is the only specie of the genera that grows wild in Italy. Metabolites from leaves and roots of this specie were compared. Moreover, at present, literature on the phytochemical characterisation of P. europaea is poor. Plumbagin was isolated in both of the samples analysed, confirming its nature in the Plumbaginaceae family as chemotaxonomic marker of the Plumbaginae tribe. In this work, hydroplumbagin-4-O-glucoside and myricetin-3-O-rhamnoside are isolated for the first time in the genus.

Iron-regulated salicylate synthesis by Pseudomonas spp.

Two iron-regulated compounds have been found in acidified ethyl acetate extracts from culture supernatants of Pseudomonas aeruginosa and Pseudomonas cepacia type-strains. Synthesis of both compounds paralleled iron-deficient growth, and was repressed in the presence of 100 microM-FeCl3. Yields of these substances varied among different strains and attained maximum levels during stationary phase. Thin layer chromatographic analysis in five different solvent systems revealed that the slower-moving compound chromatographed as two distinct bands, and showed RF values and spectral properties similar to pyochelin. The faster-moving compound co-migrated as a single band with a standard of commercial salicylic acid in each of the chromatographic systems tested. Moreover, a molecule with an identical RF was also produced by Pseudomonas fluorescens CHA401, which is known to synthesize salicylic acid as the only siderophore during iron-limited growth. Spectrophotometric and spectrofluorometric titrations led to the identification of this iron-regulated compound as salicylic acid, in agreement with the structure deduced from 1H-NMR and mass spectroscopy. The identity of the P. cepacia siderophore azurechelin as salicylic acid was also conclusively demonstrated. Salicylic acid, like pyochelin and pyoverdin, promoted P. aeruginosa growth in an iron-depleted medium. These results are consistent with a putative siderophore activity for salicylic acid, i.e. azurechelin, as has been demonstrated for P. aeruginosa, P. fluorescens and P. cepacia. Thus, salicylic acid is likely to act as a siderophore in more than one species belonging to the genus Pseudomonas.

[Spontaneous hemoperitoneum caused by gallbladder rupture: description of a case and review of the literature]. / Emoperitoneo spontaneo da rottura della colecisti: descrizione di un caso e revisione della letteratura.

The Authors report a case of spontaneous haemoperitoneum following the rupture of the gallbladder. After a review of the literature, clinical, pathogenetic, diagnostic and therapeutic problems are discussed. It is stressed that, although this condition is rare, its incidence is increasing due to the widespread use of anticoagulant therapy.

Purification and characterization of a peptidoglycan-associated lipoprotein from Haemophilus influenzae.

We have purified to homogeneity a peptidoglycan-associated protein from Haemophilus influenzae. Our purification process used differential extraction of cell envelopes with nondenaturing detergents. Solubilization of this protein was accomplished by heating a peptidoglycan-enriched subcellular fraction in the presence of one of several nondenaturing detergents at 55-60 degrees C. The purified protein migrated as a single band, with a Mr approximately 15,000, following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein contains covalently linked fatty acids, is rich in tyrosine, but lacks methionine and tryptophan. Amino acid analysis also revealed the presence of glycerylcysteine, which has been shown to be the site of fatty acylation in other bacterial lipoproteins. Over 87% of the primary structure has been determined by sequencing high pressure liquid chromatography purified fragments derived from several endoproteinase digests. This protein belongs to a family of proteins, known as peptidoglycan associated lipoproteins, which appear to be components of the outer membranes of most Gram-negative bacteria.