Martha Gattuso

Evidence for the Mechanism of Action of the Antifungal Phytolaccoside B Isolated from Phytolacca tetramera Hauman

Phytolaccoside B (1), an antifungal monodesmoside triterpenoid glycoside isolated from berries of Phytolacca tetramera Hauman (Phytolaccaceae), alters the morphology of yeasts and molds. The malformations were similar to those produced by enfumafungin, a known inhibitor of (1-->3)-beta-D-glucan synthase, an enzyme that catalyzes the synthesis of (1-->3)-beta-D-glucan, one of the major polymers of the fungal cell wall. However, enzymatic assays revealed that 1 did not inhibit (1-->3)-beta-D-glucan synthase, but it did produce a notable enhancement of the chitin synthase 1 activity and, concomitantly, a rise in chitin, another important polymer of the fungal cell walls. This finding was corroborated by fluorescence microscopy and also by quantification of the chitin. In addition, a 2-fold increase in the thickness of the fungal cell wall was observed with transmission electronic microscopy. On the other hand, 1 neither bound to ergosterol nor caused hemolysis of red blood cells, although some fungal membrane damage was observed at the MIC of 1.

Isolation of antifungal saponins from Phytolacca tetramera, an Argentinean species in critic risk

The methanolic extract of the berries of Phytolacca tetramera, an Argentinean species submitted to a great anthropic impact, and therefore in critic risk of extinction, not previously studied, showed antifungal activity against opportunistic pathogenic fungi. Through fractionation of the extract followed by agar dilution assays, three monodesmosidic triterpenoid saponins have been isolated from the butanolic extract of P. tetramera. The structures were established as phytolaccosides: B [3-O-beta-D-xylopiranosyl-phytolaccagenin], E [3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-xylopiranosyl-phytolaccagenin]. and F [3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranosyl-phytolaccagenic acid]. The three saponins belong to the olean-type triterpenoid saponins, with 28,30 dicarboxylic groups and an olefinic double bond on C-12. Phytolaccosides B and E but not phytolaccoside F, showed antifungal activities against a panel of human pathogenic opportunistic fungi. Phytolaccoside B was the most active compound and showed the broadest spectrum of action. The most sensitive fungus was Trichophyton mentagrophytes.

Comparison of Asclepiadaceae latex proteases and characterization ofMorrenia brachystephana Griseb. cysteine peptidases

Partial characterization of the crude proteolytic extracts of five Asclepiadaceae species namely Araujia hortorum Fourn., Asclepias curassavica L., Funastrum clausum (Jacq.) Schlechter, Morrenia brachystephana Griseb. and Morrenia odorata (Hook. et Arn.) Lindley, and a comparison of these results and those from other Asclepiadaceae species are reported. Additionally, the crude extract from M. brachystephana was submitted to further purification and characterization. The crude enzyme showed high proteolytic activity when assayed on casein in the presence of 12 mM cysteine but was strongly inhibited by very low concentrations of sodium iodoacetate (0.01 mM) and mercuric chloride (0.1 mM) suggesting that the enzyme belongs to the cysteinyl-proteases type. Fractioned acetone precipitation followed by cation exchange chromatography allowed the separation of two basic ( pI > 9.3) proteolytically active fractions, both homogeneous by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and with similar molecular masses (25.5 and 26 kDa).Copyright

Characterization of Lemon Verbena (Aloysia citriodora Palau) from Argentina by the Essential Oil

Abstract The oils of twenty-three samples of Aloysia citriodora from the most important growing areas in our country have been analyzed using GC/FID/MS. Characterization of the oil compositions revealed chemical markers which can be used to define the quality of a typical Argentine lemon verbena. In addition to the normal neral (20.0%) and geranial (29.0%) rich oils, two unusual oil compositions were detected: one with high contents of limonene (40.3%) and citronellal (21.6%), the other rich in β-thujone (73.4%). These specifications can be used for the standardization of this plant, defining the best available quality of leaves and volatile fractions of argentine lemon verbena, and discriminating from potentially toxic materials and adulterants.

Volatile constituents of five Baccharis Species from Northeastern Argentina

Essential oils obtained by hydrodistillation from the aerial parts of Baccharis gaudichaudiana, B. microcephala, B. penningtonii, B. phyteumoides and B. spicata collected from different locations in Argentina were analyzed. Qualitative and quantitative analysis were performed using a GC/FID/MS system with a special configuration. Essential oil yields ranged from 0.1 to 0.2% (m/v of dry material). Different chemical patterns were observed in the essential oils composition of the species studied: spathulenol and β-pinene were the main constituents in B.gaudichaudiana, whereas caryophyllene oxide and spathulenol were the major constituents in B. microcephala and B. spicata. In this latter species, β-pinene has also been found in high amounts. Germacrene D was the major compound in B. penningtonii. Finally, β-selinene and phytol acetate E were the main components in B. phyteumoides.

Inhibitory activity of xanthine-oxidase and superoxide scavenger properties of Inga verna subsp. affinis. Its morphological and micrographic characteristics.

Hexane, dichloromethane and ethanolic extracts of Inga verna subsp. affinis were evaluated as inhibitors of xanthine-oxidase and as scavengers of the superoxide produced by the action of the enzyme. Ethanolic but not hexane and dichloromethane extracts showed inhibitory properties of xanthine-oxidase (IC50=27.3 microg/ml) with an additional superoxide scavenging capacity (IC50=12.7 microg/ml). The antioxidant potential was confirmed with the free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay, which showed that the ethanolic extract scavenges 50% DPPH free radicals at 11.6 microg/ml. HPLC study of the phenol content of the active extract, revealed the presence of ellagic and gallic acids as its main constituents. The main morphological and micrographic characteristics of Inga verna subsp. affinis are described in this paper too, in order to aid in its inequivocal identification since Inga spp. are noted for their morphological variation, which makes taxonomic classification very difficult.

Ethnobotanical, pharmacognostical, pharmacological and phytochemical studies on Smilax domingensis in Guatemala

Smilax domingensis Willd., Smilacaceae, known as zarzaparrilla, is a climbing shrub from Tropical America. The rhizome is popularly used in medicine as anti-inflammatory, antiseptic, and tonic. Since 1983 studies are being conducted in Guatemala for validation of the ethnobotanical uses, particularly in vitro demonstration of antimicrobial activity, using wild material, with high variability and some taxonomic problems. This article reports the taxonomic determination, cultivation of drug material, evaluation of use by in vitro and in vivo pharmacological assays, and phytochemical characterization. Extracts from cultivated material was evaluated by antimicrobial, anti-inflammatory, analgesic and immunomodulatory models, confirming the antimicrobial and immunomodulatory activities. Phytochemistry was done in the crude drug and extracts. Quality control parameters are described (micrographic drawings and phytochemical characteristics). Evidence is presented that cultivated rhizome has antimicrobial and immunomodulatory activities, validating the popular use and helping the industrial development of phytopharmaceutical products.

Detection of synergistic combinations of Baccharis extracts with Terbinafine against Trichophyton rubrum with high throughput screening synergy assay (HTSS) followed by 3D graphs. Behavior of some of their components

Forty four extracts from nine Baccharis spp. from the Caulopterae section were tested in combination with terbinafine against Trichophyton rubrum with the HTSS assay at six different ratios with the aim of detecting those mixtures that produced a ≥50% statistically significant enhancement of growth inhibition. Since an enhanced effect of a combination respective of its components, does not necessarily indicate synergism, three-dimensional (3D) dose-response surfaces were constructed for each selected pair of extract/antifungal drug with the aid of CombiTool software. Ten extracts showed synergistic or additive combinations which constitutes a 22% hit rate of the extracts submitted to evaluation. Four flavonoids and three ent-clerodanes were detected in the active Baccharis extracts with HPLC/UV/ESI-MS methodology, all of which were tested in combination with terbinafine. Results showed that ent-clerodanes but not flavonoids showed synergistic or additive effects. Among them, bacchotricuneatin A followed by bacrispine showed synergistic effects while hawtriwaic acid showed additive effects.

Constituents of the Essential Oil from Leaves and Seeds of Blepharocalyx tweediei (Hook, et Arn.) Berg and B. gigantea Lillo

Abstract The composition of the essential oils from leaves and seeds ofBlepharocalyx tweediei and B. gigantea, two closely related taxa from Argentina, was determined by capillary GC, GC/MS and 13C-NMR. The main compounds in the oils of B. tweediei were α-and β-pinene, 1,8-cineole and limonene, linalool being also a major constituent of the oil from leaves. The oils from B. gigantea were characterized by a high percentage of 1,8-cineole, followed by β-pinene and viridiflorol.

Anatomical Identity Parameters of the Crude Drug Psidii guajavae folium

Abstract The leaves of Psidii guajavae L. (Myrtaceae) (Guava) are popularly used in tropical countries to prepare a remedy for the treatment of patients suffering of liquid stools; this traditional use is now scientifically supported by the existence in the leaf of a group of quercetin-derived flavonoids with intestinal anti-motility, spasmolytic and anti-inflammatory properties. Consequently, herbal products prepared with Psidii guajavae folium are now clinically used to treat Acute Diarrheic Disease and some are commercialized as phyto-drugs. However, there are no studies on morphology of this plant drug, particularly to determine the anatomical characters required for quality control of the raw material used in the preparation of guava-leaf phytodrugs. The present paper provides the anatomical and morphological characters that help in the authentication of Psidii guajavae leaf. Guava leaf surfaces were dissected and stained with cresyle-violet; transversal cuttings of the lamina and petiole were stained using safranine-fast green; samples were studied using procedures of light, scanning-electron and laser-scanning con-focal microscopy. Anomocytic and anisocytic stomatas in the abaxial epidermis, long unicellular trichomes and schizolysigenous secretory cavities are proposed as anatomical parameters to establish authenticity of guava leaf crude drug.