Data collection and advanced statistical analysis in phytotoxic activity of aerial parts exudates of Salvia spp

In order to define the phytotoxic potential of Salvia species a database was developed for fast and efficient data collection in screening studies of the inhibitory activity of Salvia exudates on the germination of Papaver rhoeas L. and Avena sativa L.. The structure of the database is associated with the use of algorithms for calculating the usual germination indices reported in the literature, plus the newly defined indices (Weighted Average Damage, Differential Weighted Average Damage, Germination Weighted Average Velocity) and other variables usually recorded in experiments of phytotoxicity (LC50, LC90). Furthermore, other algorithms were designed to calculate the one-way ANOVA followed by Duncan's multiple range test to highlight automatically significant differences between the species. The database model was designed in order to be suitable also for the development of further analysis based on the artificial neural network approach, using Self-Organising Maps (SOM).

Effects of demethylfruticuline A and fruticuline A from Salvia corrugata Vahl. on biofilm production in vitro by multiresistant strains of Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis.

In this study, demethylfruticuline A (dfA) and fruticuline A (fA), two quinones representing the major diterpenoid components of the exudate produced by the aerial parts of Salvia corrugata, were assessed for their ability to modify surface characteristics, such as hydrophobicity, and to inhibit synthesis of biofilm in vitro by multiresistant Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis. Five strains of S. aureus (three meticillin-resistant and two meticillin-susceptible), five strains of S. epidermidis (four meticillin-resistant and one meticillin-susceptible) and eight vancomycin-resistant E. faecalis, all recently isolated from clinical specimens and capable of slime production, were studied. fA decrease by at least two-fold the hydrophobic properties of the S. aureus cell membrane but did not affect S. epidermidis or E. faecalis. Biofilm formation on polystyrene plates was quantified spectrophotometrically by established methodologies. Inhibition of biofilm formation was also confirmed by the Congo red agar plate assay. dfA and fA were more effective against S. aureus strains (>70% effect at subinhibitory concentrations) than against S. epidermidis in inhibiting slime synthesis. Against E. faecalis, dfA at subinhibitory concentration induced an inhibition of biofilm production of ca. 60%; fA was less active and more strain-dependent. Moreover, the two compounds were shown to possess chelating activity on divalent and trivalent metal cations. Interactions of fA and dfA with bacteria could be very complex, possibly being species-specific, and could depend not only on inhibition of exopolysaccharide synthesis but also on their chelating activity and on changes in the microorganism's surface, including cell hydrophobicity.

Antimutagenic activity of a secoisopimarane diterpenoid from Salvia cinnabarina M. Martens et Galeotti in the bacterial reverse mutation assay.

The effects of 3,4-secoisopimar-4(18),7,15-trien-3-oic acid, a diterpenoid isolated from Salvia cinnabarina, were evaluated in the Ames test on Salmonella typhimurium TA98 and TA100 and on Escherichia coli WP2uvrA, in presence and in absence of the metabolic activation system. The secoisopimarane diterpenoid not only showed to be devoid of mutagenic activity, but significantly inhibited the effect of some known mutagens, in all strains tested. The reduction of the number of chemically-induced revertant colonies reached the value of 92.2% against 2-aminoanthracene, 59.6% against 2-nitrofluorene, 50.9% against sodium azide and 39.9% against methyl methane sulfonate. It is hypothesized that the secoisopimarane diterpenoid acts by aspecific mechanisms, by alterating the cell permeability thus blocking the mutagen adsorption across the bacterial membrane, or by chemical or enzymatic inhibition of the mutagens.

Triterpenoids from Salvia wagneriana.

From the exudate of Salvia wagneriana Polak, beside the known ursolic acid, two pentaoxygenated triterpenoids were isolated. Their structures were determined as 3-oxo-11alpha,19beta,20,22beta-tetrahydroxy-lupane (1) and 3beta,11alpha,19beta,20,22beta-pentahydroxy-lupane (2) using a combination of one- and two-dimensional NMR techniques.

Isolation and HPLC quantitative analysis of flavonoid glycosides from Brazilian beverages (Maytenus ilicifolia and M. aquifolium).

Aqueous infusions of Brazilian Maytenus leaves are used as beverages, foodstuffs, and phytomedicines. Previously, we isolated two new flavonoid tetrasaccharides from the infusion of Maytenus aquifolium leaves that showed antiulcer activity. In this investigation a new flavonoid tetrasaccharide, kaempferol-3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[alpha-L-arabinopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl (1-->2)]-O-beta-D-galactopyranoside (3), was isolated, together with kaempferol tri- and disaccharides and quercetin trisaccharides from the aqueous infusion of Maytenus ilicifolia leaves. All structures were elucidated by ES-MS and NMR spectroscopic methods. The quantitative analysis of the flavonoid glycosides from Maytenus ilicifolia and M. aquifolium has been performed by HPLC.

A new diterpenoid with antispasmodic activity from Salvia cinnabarina.

From the leaf surface exudate of the aerial parts of Salvia cinnabarina a new secoisopimarane diterpenoid with a non-specific spasmolytic activity on histamine-, acetylcholine-, and barium chloride-induced contractions in the isolated guinea-pig ileum was obtained. The IC50 value obtained was comparable with that obtained for papaverine. The structure of 3,4-secoisopimara-4(18),7,15-triene-3-oic acid was established by 1D and 2D NMR spectroscopic techniques.

Herbal mixtures with claimed slimming activity: determination by TLC and HPLC of illegally added drugs.

A method for the detection and quantitation of several undeclared drugs in herbal preparations with slimming activity is proposed. Samples containing various anorexics, hypoglycemics and antidepressants were prepared by addition of the drugs to a synthetic mixture containing the most commonly used plant powders for those preparations. Each sample was subjected to a treatment that permitted, after a simple ethanolic extraction, the identification of the drugs by TLC using three different solvent systems. A further purification of the ethanolic solution through a polyamide column allowed for quantitative analysis of the drugs by a RP-HPLC method. The analytical recovery was good (88-97%); the calibration curves were linear over a wide range of drug concentrations (30-500 micrograms/ml) (r > 0.9995); the precision was high (CV% = 0.4-2.8) as well as the accuracy (96-102%).

In vitro activity of a Combretum micranthum extract against herpes simplex virus types 1 and 2.

The authors demonstrate in vitro antiviral activity of a methanolic extract of Combretum micranthum leaves against HSV-1 and HSV-2. This activity is present only in the extract dissolved 7 days before the assay, but not in the freshly prepared extract, thus indicating the presence of inactive precursors which undergo spontaneous transformations into active compounds. The alkaline autooxidation of the methanolic extract promotes this rapid transformation. The precursors have been identified as condensed catechinic tannins, which, under alkaline conditions, suffer rapid cleavage, intramolecular rearrangement to catechinic acid and autooxidation. The alkaline autooxidation products of the methanolic extract of C. micranthum and those of the synthetic catechinic acid show similar I.R. and U.V. absorption curves, as well as similar anti-HSV-1 and -HSV-2 activities. EC50s of catechinic acid autooxidation products against HSV-1 and HSV-2 replication were 2 micrograms/ml and 4 micrograms/ml, respectively, when cell cultures were treated with the compound during virus infection.

Reaction of N,N-disubstituted alpha-aminomethyleneketones with tosyl isocyanate. Synthesis of amino-disubstituted 2-acyl-3-amino-N-tosylpropenamides, N,N-(3-amino-1-alkyl-2-propenylidene) and N,N-[2-(aminomethylene)cyclohexylidene]tosylamides.

The reaction of N,N-disubstituted open-chain and cyclohexane alpha-aminomethyleneketones (I) and (II) with p-toluenesulfonyl (tosyl) isocyanate gave amino-disubstituted 2-acyl-3-amino-N-tosylpropenamides (III) and/or N,N-(3-amino-1-alkyl-2-propenylidene) and N,N-[2-(aminomethylene)-cyclohexylidene] tosylamides (IV) and (V), the final product being related to the carbon and nitrogen substituents of the enaminone. The evaluation of the hypoglycemic activity concerning some of the above compounds gave no interesting results.

Synthesis and photobiological activity of N,N-disubstituted 4-amino-3-chloro-2H-thieno[2,3-h]-1-benzopyran-2-ones, 7-thioisosteres of 4-amino-3-chloroangelicins.

A convenient synthesis of a series of N,N-disubstituted 4-amino-3-chloro-2H-thieno[2,3-h]-1-benzopyran-2-ones (IV), which are 7-thioisosteres of 4-amino-3-chloroangelicins, was accomplished via dehydrochlorination and dehydrogenation of the 1,4-cycloadducts obtained by reaction of dichloroketene with N,N-disubstituted (E)-5-aminomethylene-6,7-dihydrobenzo-[b]thiophen-4(5H)-ones . Some aspects of the photobiological activity of these thioangelicins were studied; three of them (IV a, e, f) appeared to inhibit DNA synthesis in Ehrlich ascites tumor cells. The most active compound, namely 3-chloro-4-morpholino-7-thioangelicin (IV e), afforded 70% of the antiproliferative effect of 8-MOP, but unlike this reference compound was unable to induce erythema on guinea pig skin. However, compounds (IV a, f) produced a slight erythema, thus suggesting that a relationship between antiproliferative and phototoxic effects does not exist.

Cycloaddition of dichloroketene to N,N-disubstituted 3-aminomethylene-5-hydroxy-2,2-dimethyl-7-pentyl-4-chromanone: synthesis of 2H,5H-pyrano[3,2-c][1]benzopyran derivatives.

The synthesis of N,N-disubstituted 3-aminomethylene-5-hydroxy-2,2-dimethyl-7-pentyl-4-chromanones (III) and their reaction with dichloroketene are described. The resulting cycloadducts (IV) gave, by dehydrochlorination, the N,N-disubstituted 4-amino-3-chloro-10-hydroxy-5,5-dimethyl-8-pentyl-2H,5H-pyrano[3,2-c] [1]benzopyran-2-ones (V), which are structurally related to tetrahydrocannabinols. Only the compound (V a) displayed a very weak stimulant activity on the CNS.

Hemolytic action and surface activity of triterpene saponins from Anchusa officinalis L. Part 21: On the costituents of Boraginaceae.

Relationship between chemical structure, hemolytic action and surface activity of five glucosides of oleanolic acid were studied. Monodesmosidic saponins are more hemolytic than bisdesmosidic. The hemolytic activity of monodesmosides decreased with the length and the branching of the glucosidic chain. Surface activity is major in bisdesmosides. This property increases with the length of the glucosidic chain in monodesmosides. Increase of hemolytic action is accompanied by a decrease of surface activity.