Cornelis A. Salemink

Quantitative determination of the juvenile hormones in the haemolymph of Locusta migratoria during normal development and after implantation of corpora allata

Simultaneous quantitative determination of the three naturally occurring juvenile hormones in insects (JH-I, JH-II and JH-III) was performed on haemolymph samples of both normally developing locusts and locusts implanted with active corpora allata, using capillary gas chromatography with electron capture detection. In fourth instar female larvae, 24–48 hr after the third ecdysis, as well as in adult females, 18 days after the imaginal ecdysis, only JH-III was detected. In fifth instar female larvae JH-III was present in very low concentrations, if at all. After implantation of four pairs of corpora allata taken from young fourth instar female larvae or one pair or corpora allata taken from adult females into fifth instar female larvae 0–24 hr after ecdysis, an elevation of the JH-III titre was observed. Neither JH-I nor JH-II could be detected. The amount of JH-III, already elevated 2 hr after implantation, remained high for several days in comparison to that of control insects. On the third day after the subsequent moult the JH-III level was comparable to that of normally developing fifth instar larvae. Factors involved in the achievement of the haemolymph JH-titre are discussed.

Essential oils of five Tanacetum vulgare genotypes

Abstract The essential oils of five Tanacetum vulgare genotypes were investigated and their main components identified. Artemisia alcohol, γ-campholenol, davanone, lyratol, lyratyl acetate and 4-thujen-2α-yl acetate have not been reported before as constituents of Tanacetum vulgare . This is the first time that γ-campholenol has been isolated from a natural source. 4-Thujen-2α-yl acetate is a novel compound.

The structure of cercosporin, a naturally occurring quinone

The structure suggested for cercosporin, a naturally occurring dihydroxy-perylenequinone, is unusual in having a methylenedioxy-group present in a seven-membered ring bridging a biphenyl system.

Biological activity of the alkaloids of Erythroxylum coca and Erythroxylum novogranatense

The cultivated Erythroxylum varieties E. coca var. coca, E. coca var. ipadu, E. novogranatense var. novogranatense and E. novogranatense var. truxillense contain 18 alkaloids, identified so far, belonging to the tropanes, pyrrolidines and pyridines, with cocaine as the main alkaloid. The biological activity of the following alkaloids has been reported in the literature: cocaine, cinnamoylcocaine, benzoylecgonine, methylecgonine, pseudotropine, benzoyltropine, tropacocaine, alpha- and beta-truxilline, hygrine, cuscohygrine and nicotine. The biological activity of cocaine and nicotine is not reviewed here, because it is discussed elsewhere in the literature. Hardly anything is known about the biological activity of the other alkaloids present in the four varieties mentioned. The biosynthesis of the coca alkaloids has been outlined.

Cannabis—VIII : Pyrolysis of Cannabidiol. Structure elucidation of the main pyrolytic product

Abstract GLC analysis of the products obtained by pyrolysis of cannabidiol in air at 700° revealed the formation of several components, which are not only the result of a mere cracking process. A peak with a retention time corresponding to the one of Δ1(2)tetrahydrocannabinol has been analysed by mass spectrometry. Next to at least two components with a molecular weight of 314 (C21H30O2), possibly including a small amount of Δ1(2)tetrahydrocannabinol, the major component was shown to have the molecular formula C21H30O3. The structure of this oxidation product of cannabidiol has been established as the decarboxylated product of the naturally occurring cannabielsoic acid A by the identity of its mass spectrometrical fragmentation pattern to that of one of the two decarboxylated cannabielsoic acid A C1-stereoisomers, obtained by photochemical oxidation of cannabidiolic acid.

Triterpenes of Prunus serotina and P. lusitanica

Abstract The leaves of Prunus serotina and P. lusitanica contain a new triterpene, 2α,3α-dihydroxyurs-12-en-28-oic acid, isolated in form of its methyl ester. Other triterpenes present in these species are ursolic acid and ursol aldehyde. P. lusitanica also yields friedeline.

Influence of alterations in the purine ring on biological activity of cytokinins

Abstract The 1-deaza-, 3-deaza-, 8-aza-1-deaza- and 8-aza-3-deaza-analogs of kinetin and 6-(3-methyl-2-butenylamino)purine and some of their ribosides were synthesized and their growth-promoting activities in the tobacco bioassay were determined and compared with those of the parent compounds. The replacement of nitrogen by carbon in the 1 -position of the purine ring decreases cytokinin activity 15-fold for kinetin and 2-fold for 6-(3-methyl-2-butenylamino)purine (IPA); however, the replacement of nitrogen by carbon in the 3-position decreases the activity 2000 times for kinetin and 1000 times for 6-(3-methyl-2-butenylamino)-purine. The activity of 8-aza-1-deaza-analogs appears to be of the same order of somewhat lower than the corresponding 1-deaza-analogs. The corresponding 8-aza-3-deaza-analogs are less active than kinetin (400 times and 6-(3-methyl-2-butenylamino)purine (40 times). However, they are more active than the corresponding 3-deaza-analogs. The concentration range in which the ribosides show activity is nearly the same as for the corresponding free bases, but the maximum yield of tobacco-callus for the riboside of the 3-deaza-analog of 6-(3-methyl-2-butenylamino)purine is very low.

Biological activity of the alkaloids of Papaver bracteatum Lindl

Thebaine is the main alkaloid found in P. bracteatum Lindl. Many minor alkaloids are present. To date 31 have been identified, some by chromatography and mass spectrometry only. They represent 10 of the 14 alkaloid classes found in the genus Papaver (structures and classes are given in Fig. 1). Many of them occur in other plant species, sometimes as the main alkaloid. The biological activity of the following alkaloids has been reported in the literature: codeine, thebaine, isothebaine, (—)-nuciferine, protopine, tetrahydropalmatine, and coptisine. The biological activity of codeine has not been reviewed here because it is an established drug and its pharmacology has been reviewed in the literature. Thebaine and isothebaine are both narcotics and analgesics. However, their therapeutic utility is limited because of their high toxicity and severe side-effects. Thebaine produced congenital malformations in a small number of test animals after a single injection of a high dosage. It has a limited dependence capacity. (—)-Nuciferine is a CNS depressant. Its action strongly resembles that of chlorpromazine. In a chronic toxicity test it caused liver and kidney damage in dogs. Protopine has a sedative effect in test animals. It has bactericidal and cytotoxic properties, but is inactive against carcinomas in vivo.

The use of metastable ion characteristics for the determination of ion structures of some isomeric cannabinoids

The mechanism of formation of the prominent C15H19O2 ion at m/e 231 in the mass spectra of Δ1(6)-tetrahydrocannabinol and five isomeric cannabinoids has been investigated. Except via a well-documented two step process, involving an RDA mechanism, a sizeable percentage of these ions is formed by a novel one-step route from the molecular ion. This was deduced from the spectra of deuterium-labelled compounds and measurements of the kinetic energy release of metastable ions. The latter value for the one step process varies from 25–44 meV for the six compounds investigated, attributed to two interdependent effects, different transition state geometries and common transition states differing in the time elapsing before their formation.

Corypalline and O-methylcorypalline, two alkaloids from Papaver bracteatum☆

Abstract Two new Papaver alkaloids, corypalline and O -methylcorypalline, were identified from P. bracteatum . These alkaloids are considered as the biosynthetic precursors of N -methylcorydaldine in this plant.