A number of structurally novel polyhydroxylated quinolizidines have been prepared starting from 2-deoxyglycosylamines which in turn were derived from D-glycals by following a methodology developed in our laboratory. In our strategy, Grignard reaction and ring-closing metathesis (RCM) reactions are the key steps to construct the desired skeletons. All synthesized final molecules were checked for...

Steviol glycosides are found in high concentrations in the leaves of the Paraguayan perennial herb Stevia rebaudiana and their intense sweetness, as well as high concentration in Stevia leaf tissue, has made them the subject of research interest for over 100 years. Steviol glycosides are diterpenoids whose biosynthetic pathways share four steps in common with gibberellic acid formation. The con...

The toxicity of Thesium lineatum is confirmed in sheep. A toxic crystalline bufadienolide, with the suggested trivial name thesiuside, has been isolated from it. This is the first cardiac glycoside to be isolated from a member of the Santalaceae. The toxin appears to have no cumulative effect and the symptoms of intoxication and pathology in sheep are similar to that expected from acute cardiac...

A carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields with high selectivity. The versatility of this method has been demonstrated by applying it to differently protected glycals and by employing several nucleophiles. The obtained C-allyl glycoside has been utilized for the synthesis of a orthogonally protected ...

Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3beta-ol, were isolated from the leaves of Croton zambesicus, together with trans-phytol, beta-sitosterol, alpha-amyrin and stigmasterol. The structures were determined by extensive NMR techniques and X-ray analysis. The cytotoxicity of these compounds has be...

Since the 1960s, fungal infections have become a major worldwide public health problem. Antifungal treatments have many limitations, such as toxicity and resistance. Matayba guianensis Aublet (Sapindaceae) was chemically investigated as part of our ongoing search for lead molecules against fungi in the Brazilian Cerrado biome. The ethanolic extract of M. guianensis root bark revealed the presen...

A new acyclic guanidine alkaloid, canarosine (1), together with five known compounds, beta-sitosterol (2), stigmasterol (3), daucosterol (4), epi-inositol 6-O-methyl ether (5), and rutin (6), were isolated from the aerial parts of Canavalia rosea. Their structures were established on the basis of their spectroscopic data. In the radioligand receptor binding assay, canarosine (1), at a concentra...

Asteracantha longifolia (L.) Nees, Acanthaceae, is a source of the ayurvedic drug, ‘Kokilaaksha’ and the Unani drug, Talimakhana. The seeds are acrid, bitter, aphrodisiac, tonic, sedative, used for diseases of the blood. The plant is known to possess antitumor, hypoglycemic, aphrodisiac, antibacterial, free radical scavenging and lipid peroxidation, hepatoprotective and haematopoietic activity....

Two new 13,28-epoxy oleanane-type triterpenoids, namely heterogenoside E and F, were isolated from Lysimachia heterogenea Klatt, together with the eight known compounds: palmitic acid, β-stigmasterol, kaempferol, quercetin, hyperin, isorhamnetin, isorhamnetin-3-O-galactopyranoside and anagallisin C. Heterogenoside F possesses acetoxyl groups at the unusual C-21 and C-22 positions of its oleanan...

Trichilia catigua is a Brazilian native species known as “catuaba”. This study investigated the chromatographic features hydroalcoholic extracts that were obtained by different techniques, from barks and leaves. The chromatographic analysis has demonstrated the presence of chlorogenic acid, epicathechin and cathechin, as well as the presence of β-sitosterol and stigmasterol in both analyzed pla...