Abstract. Cholangiohepatopathy was induced in 5 lambs by oral administration of extracts from signal grass (Brachiaria decumbens) in Brazil. Grossly there were pale foci multifocally distributed throughout the hepatic parenchyma in 4 lambs. The microscopic changes, which were similar to those produced by other steroidal sapogenins-containing plants such as Tribulus terrestris and Panicum spp., included multifocal cholangitis, bile duct proliferation, and the presence of crystals in the biliary system. Sporadic outbreaks of photosensitization in ruminants grazing on signal grass (Brachiaria decumbens) have been reported. 9,21 Cases of photosensitization occurring on this grass in Brazil had formerly been ascribed to intoxication by sporidesmin from spores of the saprophytic fungus Pithomyces chartarum. 2,7,8 However, the potential importance of steroidal saponins present in B. decumbens has been established, suggesting that photosensitization by this grass belongs to the group of plant-induced hepatogenous photosensitizations, 9,21 which are also induced by Panicum spp., 3,10,19 Tribulus terrestris, 11,16 Agave lecheguilla, 4 and Narthecium ossifragum. 17 All of these plants contain steroidal saponins and have been associated with cholangitis and deposition of crystals in the biliary system, causing photosensitization in sheep. Furthermore, steroidal sapogenins have been isolated from bile and biliary crystals of sheep fed those plants. 4,10,16,17 The plant saponins are converted by ruminal metabolism into ␤-D-glucuronides of sapogenins, which in the presence of calcium may precipitate, forming the characteristic biliary crystals. 14,21 Diosgenin and yamogenin have been detected from B. decumbens samples and from a mixture of metabolites in the rumen of sheep grazed on B. decumbens. 6,12,14,20 The arguments against involvement of P. chartarum in most Brazilian outbreaks include the low density or even absence of spores and the failure of most fungal isolates to produce sporidesmin. 5,6,[13][14][15]21 Typical photosensitivity has been reproduced in sheep grazing pure pastures of B. decumbens with no detected P. chartarum spores. 6 The aim of the present study was to reproduce hepatic lesions and photosensitization in sheep by oral administration of fractionated extracts from B. decumbens, as has been done with T. terrestris, 11,16 A. lecheguilla, 18 and N. ossifragum. 1 Counts of P. chartarum spores 15 were performed on pasture samples of plant material used for extraction. Forty kilograms of air-dried samples of B. decumbens were powdered and extracted by maceration, using 80 liters ethanol for 7 days at room temperature. A second maceration was performed, and the extracts were mixed. The solvent was evaporated, and the residual alcoholic phase was suspended in water and partitioned with dichloromethane, yielding the dichloromethane and aqueous fractions. After concentration in vacuum and at low temperature (Ͻ55 C), those fractions resulted in 500 g and 1.6 kg of syrupy residues, respectively, which corresponde...

From the leaves of Ilex affinis and Ilex buxifolia, two adulterant species of "erva mate" (Ilex paraguariensis), three new triterpenoid glycosides were isolated. Affinoside 1 (3beta-O-[beta-D-glucopyranosyl-(1-->3)-[2-O-acetyl-(1-->2]]-alpha-L-arabinopyranosyl pomolic acid 28-O-beta-D-glucopyranosyl ester, 1) was isolated from I. affinis, while buxifolioside I (28-O-beta-D-glucopyranosyl ester of (20S)-3alpha,19alpha-dihydroxyurs-12-ene-23,28-dioic acid, 7) and buxifolioside II (28-O-beta-D-glucopyranosyl ester of (20S)-3beta,19alpha-dihydroxyurs-12-en-24,28-dioic acid, 8) were isolated from I. buxifolia. Along with these new compounds, ilexoside II (2), ursolic acid (3), 28-nor-ursolic acid (4), 3beta-O-acetylursolic acid (5), and uvaol (6) were also isolated. The observed results confirm the structural specificity of the I. paraguariensis triterpenoids and reinforce a previous proposal to detect mate adulteration by triterpenoid analysis. In addition, the in vitro antitrypanosomal activity of some Ilex triterpenoids is also reported.

Extraction of Ilex dumosa leaves, a material frequently used for the adulteration of erva-maté, resulted in the isolation of 3-O-β-d-glucuronopyranosyl-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid, 3-O-β-d-6-O-methylglucuronopyranosyl-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid, and three new saponins:  3-O-[β-d-glucopyranosyl-(1−2)-β-d-galactopyranosyl]-28-O-β-d-glucopyranosyl-3β,29-dihydroxyolean-12-en-28-oic acid, 3-O-[α-l-arabinopyranosyl-(1−2)-α-l-arabinopyranosyl]-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid, 3-O-β-d-galactopyranosyl-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid. None of these saponins are present in the leaves of Ilex paraguariensis (genuine erva-maté). Keywords: Ilex paraguariensis; Ilex dumosa; erva-maté; saponins

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A new abietane diterpene, the 19-O-beta-D-glucopyranoside of 16-hydroxylambertic acid was isolated from the leaves of Quillaja brasiliensis together with a known prosapogenin (3-O-beta-D-glucuronopyranosyl-quillaic acid), quercetin, and rutin. The new compound was identified by chemical and spectroscopic methods.

Quatro saponinas esteroidais e três sapogeninas foram identificadas das partes aéreas de Brachiaria decumbens. As estruturas desses compostos foram estabelecidas através de métodos químicos e espectroscópicos (RMN de 1 H e 13 C, HMBC, HMQC) como 3b-metóxi-lanost-9(11)-eno (1),Esses compostos foram isolados pela primeira vez em B. decumbens, sendo que o composto 4b não foi ainda descrito na natureza conforme revisão realizada.Four steroidal saponins and three sapogenins were identified from aerial parts of Brachiaria decumbens. Their structures were established by chemical and spectroscopic means ( 1 H and 13 C NMR, HMBC, HMQC) as 3b-methoxy-lanost-9(11)- -5-en-3b-ol (4b). All these compounds were isolated for the first time from B. decumbens and compound 4b is described for the first time as far as we know.

Platelet interactions with collagen are orchestrated by the presence or the migration of platelet receptor(s) for collagen into lipid rafts, which are specialized lipid microdomains from the platelet plasma membrane enriched in signalling proteins. Electron microscopy shows that in resting platelets, TIIICBP, a receptor specific for type III collagen, is present on the platelet membrane and associated with the open canalicular system, and redistributes to the platelet membrane upon platelet activation. After platelet lysis by 1% Triton X-100 and the separation of lipid rafts on a discontinuous sucrose gradient, TIIICBP is recovered in lipid raft-containing fractions and Triton X-100 insoluble fractions enriched in cytoskeleton proteins. Platelet aggregation, induced by type III collagen, was inhibited after disruption of the lipid rafts by cholesterol depletion, whereas platelet adhesion under static conditions did not require lipid raft integrity. These results indicate that TIIICBP, a platelet receptor involved in platelet interaction with type III collagen, is localized within platelet lipid rafts where it could interact with other platelet receptors for collagen (GP VI and alpha2beta1 integrin) for efficient platelet activation.

Cell cycle progression is dependent on intracellular iron level and chelators lead to iron depletion and decrease cell proliferation. This antiproliferative effect can be inhibited by exogenous iron. In this work, we present the synthesis of new synthetic calix[4]arene podands bearing two aspartic/glutamic acid, ornithine groups or hydrazide function at the lower rim, designed as potential iron chelators. The synthesis only afforded calix[4]arenes in the cone conformation. We report their effect on cell proliferation, in comparison with the new oral chelator ICL670A (4-[3,5-bis-(2-hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid). The antiproliferative effect of these new compounds was studied in the rat hepatoma cell line Fao by measuring mitochondrial succinate dehydrogenase activity. Their cytotoxicity was evaluated by extracellular LDH activity. Preliminary results indicated that among all tested compounds, monohydrazidocalix[4]arene 2 which is not cytotoxic in Fao cells exhibits interesting antiproliferative activity. This effect, independent on iron depletion, remains to be further explored. Moreover, it also shows that new substituted calix[4]arenes could open the way to new valuable medicinal chemistry scaffolding.