We report the first total synthesis of the complex akuammiline alkaloid picrinine, which was first isolated nearly five decades ago. Our synthetic approach features a concise assembly of the [3.3.1]-azabicyclic core, a key Fischer indolization reaction to forge the natural product's carbon framework, and a series of delicate late-stage transformations to complete the synthesis. Our synthesis of...

In the course of our previous work we isolated alkaloids such as agroclavine-I and epoxy-agroclavine-I from Penicillium citrinum VKM FW-800 as a microorganism isolated from permafrost1,2). This fungus was shown to coproduce two other alkaloid compounds, which were extractable only under acidic conditions. Positive staining by Dragendorff's reagent but negative Ehrlich reaction suggested the occ...

Tetrahydropapaveroline (THP), a neurotoxic tetrahydroisoquinoline alkaloid formed by condensation between dopamine and dopaldehyde, has been speculated to cause Parkinson's disease and also to contribute to alcohol dependence. Having two catechol moieties, THP may readily undergo oxidation to form an o-quinone intermediate with concomitant production of reactive oxygen species, which can cause ...

Seven new indole alkaloids (1-7) comprising four vobasine, two tacaman, and one corynanthe-tryptamine bisindole alkaloid were isolated from the stem-bark extract of a Malayan Tabernaemontana. Two of the new vobasine alkaloids (1, 3), as well as 16-epivobasine (15) and 16-epivobasenal (17), showed appreciable cytotoxicity toward KB cells (IC50 ca. 5 μg/mL). The structure of the known Tabernaemon...

Morphological characteristics of two types of elements in the submerged mycelium of Claviceps paspali are described. Distribution of polysaccharides in the cell wall and cytoplasm was cytochemically determined at the ultrastructural level. Polysaccharide deposition into the cell walls was proportional to the increase in the alkaloid yield. In the cytoplasm, on the other hand, the presence of po...

Alkaloid contents (sparteine accounted for more than 80%) of four subspecies of Chamaecytisus proliferus (tagasaste) were higher in spring cuts than in autumn cuts, and they were (g kgÿ1 DM for spring and autumn cuts, respectively) 2.9 and 1.6 for palmensis subspecies, 7.3 and 2.9 for canariae, 11.3 and 7.9 for meridionales and 2.7 for the autumn cut of calderae. Voluntary intake was determined...

Background and objectives: Many members of the Amaryllidaceae are regarded as toxic. The toxic constituents that occur in the whole family are referred to as the Amaryllidaceae alkaloids. The main aim of this study was the identification of alkaloid compounds from Galanthus transcaucasicus Fomin, a medicinal plant from Amaryllidaceae. Methods: Planar and column chromatography techniques were us...

This study applied response surface methodology and synthetic evaluation method to optimize the alkaloid content of buckwheat sprouts. Solid-liquid (1:10-1:30), ethanol concentration (60%-80%), extraction temperature (20°C-60°C) and extraction time (20-40 min) were considered as treatment factors in the optimization. All treatment variables shown significant effects on the alkaloid content of b...

The alkaloid chemistry of the venom of hybrid fire ant, Solenopsis richteri × Solenopsis invicta, was investigated using silica gel chromatography and GC-MS techniques. In addition to most cis alkaloids of parental species, S. richteri Forel and S. invicta Buren, the cis alkaloid fraction of the body extract of hybrid fire ants also contains five significant new alkaloids. Hydrogenation of the ...

N,β-D-glucopyranosyl vincosamide (GPV), a major alkaloid of Psychotria leiocarpa, constitutes up to 2.5% of the dry weight in leaves. Alkaloid content was not elicited by mechanical wounding or jasmonate. At concentrations found in natural conditions or 2.5 fold higher, GPV did not inhibit herbivory in two unrelated generalist models (Helix aspersa and Spodoptera frugiperda) or in a specific in...