Jack L. Beal

Iridoids. A Review

Tre review presents a glossary of the iridoid glycosides, secoiridoids, bis-iridoids, and non-glycosidic iridoids. The following information is present for each compound, when available: structural formula, molecular formula, molecular weight, mp and [alpha]D values, uv, ir, 1H-nmr, 13C-nmr, and ms data, as well as mp and [alpha]D values for the correspondent acetate derivative. The natural source, the family and generic name, is given as well as the reference. A cross index and molecular weight tables are presented.

Alkaloids of Thalictrum. X. Two new alkaloids from T. minus var. adiantifolium: noroxyhydrastinine and thalifoline.

Abstract Two new isoquinolone alkaloids, noroxyhydrastinine (I) and thalifoline (II) have been obtained from T. minus L. var. adiantifolium Hort. Characterization by physical methods and chemical synthesis have shown the former to be 6,7-methylenedioxy-1-oxo-1,2,3,4-tetrahydroisoquinoline and the latter to be 2-methyl-6-methoxy-7-hydroxy-1-oxo-1,2,3,4-tetrahydroisoquinoline.

Codonocarpus alkaloids—III : The structure of codonocarpine☆

Abstract The structures of two Lunaria-type alkaloids, codonocarpine and N-methylcodonocarpine, from Codonocarptis australis were established by a series of chemical transformations and spectral studies.

MEVALONIC ACID AS A PRECURSOR IN THE BIOGENESIS OF DIGITOXIGENIN

(±)‐Mevalonic acid‐2‐14C has been injected into a growing plant of Digitalis lanata L. to test if this acid serves as a precursor in the biosynthesis of cardenolides. After nine days a portion of the leaves was extracted and the constituents submitted to paper chromatography followed by autoradiography. The carbon 14 was detected in the lipid fraction and in the cardiac glycoside spots, but mostly in an area containing an as yet unidentified compound. Of the two glycosides forming the major glycoside area, one was predominant and, as after Mannich hydrolysis and chromatography, glucose, digitoxose and digitoxigenin were identified, this corresponds to lanatoside A. The aglycone fraction contained the radioactivity.

Reticuline: A dopamine receptor blocker

Abstract Reticuline, a benzylisoquinoline alkaloid, inhibited specific [3H] dopamine binding to dopamine receptors in tissue homogenates from rat corpora striata. The alkaloid blocked amphetamine-induced circling behavior in mice with unilateral (chemically-induced) degeneration of dopaminergic neurons in the corpus striatum. Blockade of apomorphine-induced climbing behavior by reticuline was observed in mice. Reticuline did not produce catalepsy at doses which blocked circling behavior. These results show that reticuline is a dopamine receptor blocking agent in the central nervous system.

A Study of the Cyanogenetic Content and Toxicity of the Fruit of Selected Species of Cotoneaster

Cyanogenetic glycosides were found to be present in the leaf, bark and fruit of eight species of Cotoneaster. A quantitative determination of cyanogenetic material was made on the leaf, bark and fruit of C. divaricate at three different periods in the growing season. The leaf was found to have the greatest percentage of cyanogenetic glycosides and the fruit the least. Seasonal variation was found to be greatest in the fruit where it was demonstrated that the cyanogenetic content decreased as the fruit aged. Toxicity of the fruit of C. divaricata was studied in the dog, cat and rat. On the basis of the cyanogenetic glycoside determinations and the toxicity studies it was concluded that classification of these eight species of Cotoneaster as poisonous was not warranted.

Codonocarpine, a new lunaria-type alkaloid from Codonocarpus australis A. Cunn.

The structure of a new lunaria-type alkaloid, codonocarpine, has been established by physical and chemical methods.

Alkaloids of Thalictrum angustifolium.

Fractionation and chromatography of the ethanolic extract of the roots of Thalictrum angustifolium L. (Ranunculaceae) afforded five alkaloids: noroxyhydrastinine (1), O-methylthalicberine (2), berberine iodide (3), jatrorrhizine iodide (4), magnoflorine iodide (5). In addition, one simple aromatic compound, methyl-4-hydroxybenzoate (6), was also isolated. These compounds were identified via comparison of their spectral data with authentic compounds or spectra available within our laboratory. This is the first reported isolation of these compounds from this species.

The total synthesis of the thalictrum alkaloid adiantifoline

A total synthesis of compound (I) was accomplished and the product shown to be identical with the Thalictrum alkaloid, adiantifoline.