Aarre Huhtikangas

Phloroglucinol derivatives of Hagenia abyssinica

Abstract Four phloroglucinol derivatives have been isolated from Hagenia abyssinica (Bruce) Gmel. The structure (IV) and partial structures (V), (VI) and (VII) are proposed. All are mixtures of isobutyryl (iB), isovaleryl (iV) and 2-methylbutyryl (2-MeB) side chain homologues. The two latter acyl groups have been detected for the first time in kousso.

An Enzyme-Linked Immunosorbent Assay for the Antineoplastic Agent Vincristine

An enzyme-linked immunosorbent assay for vincristine was developed, based on a new procedure for synthesizing the hapten-protein conjugate. In both the immunogen and the enzyme tracer a spacer group was introduced between the hapten and protein, and the vincristine was coupled at a site far from its functional groups. The antibody produced proved to be exceptionally specific as compared with previous immunoassays for bis-indole alkaloids. Thousandfold antibody dilutions could be used and samples at the femtomole range were assayable. Applications of the method to patient plasma samples and to plant material are described.

Phloroglucinol derivatives in Dryopteris parallelogramma and D. patula

Abstract The phloroglucinol composition in two tropical American ferns, Dryoperis parallelogramma and D. patula has been investigated. Dryopteris parallelogramma , a member of the D. filix-mas complex, contains filixic acids, which are a characteristic of the group. Dryopteris patula contains aspidin, as do its relatives in the D. dilatata complex, and albaspidin- AA .

Feeding experiments using suspension cultures of Atropa belladonna; limiting steps in the biosynthesis of tropane alkaloids.

Abstract Relatively low levels of tropane alkaloid precursors (tropic acid, tropinone and tropanol) and alkaloids (hyoscyamine and scopolamine) were fed to suspension cultures of Atropa belladonna with repressed alkaloid synthesis to study the transport of these compounds into the cells, to detect possible limiting steps in the biosynthetic pathway and to find ways of stimulating alkaloid production. At the end of the experiments, the cell levels of tropic acid and tropinone had reached the initial nutrient medium concentrations, while cell levels of tropanol, hyoscyamine and scopolamine were high, suggesting an active uptake mechanism. Increased intracellular precursor levels did not forward the biosynthesis of the tropane alkaloids.

Gas chromatographic-mass spectrometric analysis of major indole alkaloids of Catharanthus roseus

GC-MS method for the simultaneous direct detection of vindoline and ajnalicine and for the detection of catharanthine as a pentafluoropropionate derivative from C. roseus cells after a simple purification procedure

Gas chromatographic analysis of tropic, benzoic and cinnamic acids, biosynthetic tropane alkaloid precursors

Abstract A capillary gas chromatographic (GC) method was developed for the determination of tropic, benzoic and cinnamic acids, which are established precursors of many important naturally occurring tropane alkaloids. The acids were derivatized (esterified) by extractive alkylation with pentafluorobenzyl bromide with catalysis by tetrabutylammonium ions. With mandelic acid as internal standard, a direct GC analysis of the methylene chloride extract provides a simple and reliable assay which is applicable to complex sample matrices.

Radioimmunoassay of Trospiumchloride, A Quaternary Tropane Derivative

A specific radioimmunoassay (RIA) has been developed for the determination of picogram amounts of trospiumchloride, an anticholinergic agent, from unpurified serum and urine samples. Practically no interference was observed for various potential crossreacting compounds tested. The method is sensitive and excellent values for accuracy, precision and correlation were obtained.