R. Wijnsma

Anthraquinones as phytoalexins in cell and tissue cultures of Cinchona spec.

The addition of autoclaved mycelia of Aspergillus niger and the known phytopathogenic fungus Phytophtora cinnamomi to cultured cells of Cinchona ledgeriana Moens. caused a marked increase in the anthraquinone content of the plant cells. This finding in combination with the antimicrobial activity of the anthraquinones isolated from calli of Cinchona pubescens Vahl. led to the conclusion that anthraquinones are phytoalexins.

Anthraquinones in callus cultures of Cinchona ledgeriana

Abstract From callus cultures of Cinchona ledgeriana seven known anthraquinones, purpurin, anthragallol-1,2-dimethylether, anthragallol-1,3-dimethylether, rubiadin, 1-hydroxy-2-hydroxymethylanthraquinone, 1-hydroxy-2-methylanthraquinone and morindone-5-methylether (or 1,7-dihydroxy-8-methoxy-2-methylanthraquinone), and eight new anthraquinones, 5,6-dimethoxy-1-(or -4-)hydroxy-2-(or -3-)hydroxymethylanthraquinone, 5-methoxy-2-(or -3-)methyl-1,4,6-trihydroxyanthraquinone, 2-hydroxy-1,3,4-trimethoxyanthraquinone, 4-methoxy-1,3,5-trihydroxyanthraquinone, 1,4-dimethoxy-2,3-methylenedioxyanthraquinone, 1,3-dihydroxy-4-methoxyanthraquinone, 1,3-dihydroxy-2,5-dimethoxyanthraquinone and 2,5-(or 3,5-)dihydroxy-1,3,4-(or -1,2,4-)trimethoxyanthraquinone have been isolated.

High-performance liquid chromatographic determination of indole alkaloids in a suspension culture of Tabernaemontana div aricata

Abstract A method is reported for the determination of alkaloids in cell cultures of Tabernaemontana species. The alkaloids were isolated by means of C 8 pre-concentration columns. After recovery they were analysed on a Phenyl type of column using phosphate buffer (pH 3.9)-acetonitrile-2-methoxyethanol (80:15:5) as the mobile phase. Detection was effected at 275 and 313 nm and peak-height ratios were used for identification.

Anthraquinones in the Rubiaceae

This review has been written in order to update the literature on anthraquinones occurring in the Rubiaceae. Since appearance of the excellent book on naturally-occurring quinones by R.H. Thomson (120) in 1971 about 50 new anthraquinones have been isolated from members of the Rubiaceae. Also several new methods have been used for structure analysis and separation of the anthraquinones which have not been subject to review before. For this review we have confined ourselves to the naturally occurring anthraquinones and therefore the synthesis of anthraquinones is not included. The article covers the literature from 1969 to 1984.

Influence of various media constituents on the growth of Cinchona ledgeriana tissue cultures and the production of alkaloids and anthraquinones therein

Using the methods reported by De Fossard et al. (11) the influence of various media constituents on the growth and the alkaloid and anthraquinone production in Cinchona ledgeriana callus cultures was studied. Growth and indole alkaloid production (e.g. cinchonamine) was improved by higher auxin levels. The best growth was observed in the light, although many media resulted in no growth at all in the light. Anthraquinone production was highest at lower auxin levels. Quinoline alkaloid levels (e.g. quinidine) were highest in media with low auxin concentrations. Low and medium cytokinin concentration benefited the quinoline alkaloid production.From the results it was concluded that the pathways leading to the various secondary products, anthraquinones, indole alkaloids and quinoline alkaloids are, at least partly, regulated independently.

Indole alkaloids from a callus culture of Tabernaemontana elegans

Abstract Fourteen indole alkaloids have been isolated from a callus culture of Tabernaemontana elegans . One of them is new, 3-oxo-isovoacangine, the others are the known isovoacangine, 3- R / S -hydroxy-isovoacangine, 3- R / S -hydroxy-coronaridine, isositsirikine, geissoschizol, tabernaemontanine, vobasine, vobasinol, apparicine, 16-hydroxy-16,22-dihydro-apparicine, tubotaiwine, 3- R / S -hydroxy-conodurine and monogagaine. The alkaloid content is similar to that of the whole plant, except for the absence ofthe tabernaelegantines, which were major components in the plant extract.

The influence of initial sucrose and nitrate concentrations on the growth of Cinchona ledgeriana cell suspension cultures and the production of alkloids and anthraquinones

The influence of initial concentrations of two of the major medium components, sucrose and nitrate, on the growth and the production of alkaloids and anthraquinones in cell suspension cultures of Cinchona ledgeriana Moens was studied. It was found that maximum growth and maximum alkaloid yield were obtained with a B5-medium containing the normal level of nitrate and 4% sucrose, whereas the anthraquinone yield was maximum at 8% sucrose at the normal level of nitrate. Maximum contents of secondary metabolites, expressed as μg.gDW-1, were found using a medium containing 2% sucrose, but four times the normal nitrate concentration.

Plant Cell and Tissue Culture of Cinchona Species

The genus Cinchona, belonging to the family Rubiaceae, is still esteemed for its anti-malaria activity. Several species, e.g. C. pubescens (syn. C succirubra) and C. ledgeriana,, have been cultured in plantations during the past 130 years for the production of Cinchona bark, the raw material for the alkaloids quinine and quinidine. Cinchona plantations are mainly found in Middle-America, Central Africa, India, Phillipines, and Indonesia. After 7–12 years of growth the bark of the trees is harvested. The alkaloid content is then about 10%–15% (Smit 1984).

Conditioning of Media: An Elaborate Method of Optimizing Initial Growth Hormone Concentration

The conditioning of media is a well-known method for growing plant cells at low density (Street 1977). Stuart and Street (1969) studied the conditioning effect in more detail. They were able to prove a conditioning effect for Acer cell cultures. The critical initial cell density of such cultures could be lowered by a factor of at least 10 by using a conditioned medium. It was also attempted to define the chemical basis of the conditioning effect (Stuart and Street 1971). From experiments measuring the cell numbers after 4 weeks of culture of different initial cell densities on various (conditioned) media, the authors concluded that the carbon course, the vitamins and other growth factors as well as the growth hormones (2,4-D and kinetin) were probably not involved in the conditioning effect. Analysis of a conditioned medium showed the presence of a series of amino acids in small amounts. Addition of these compounds to a non-conditioned medium indeed resulted in a lowering of the critical initial cell density, however, not to the same level as a conditioned medium. Furthermore, a volatile factor was proven ro be involved in the conditioning effect.

HPLC Analysis of Alkaloids in Extracts of Callus Cultures of Cinchona Species

Abstract The quantitative analysis of the alkaloids in Cinchona tissue cultures by means of a reversed-phase ion pair HPLC method is reported.