English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

KlAmbt, Thies, and Skoog' have described the isolation and the biological effects on tobacco tissue cultures of several organic bases, obtained as their picrates, from large-scale batches of Corynebacterium fascians. In a cooperative effort with the Wisconsin workers, we have been able to identify these substances, by spectrometric means and by comparison with authentic samples, as the picrates of 6-(yy-dimethylallylamino)purine (designated as II), nicotinamide (III, IV), and 6-methylaminopurine (V). The activity of the first of these compounds in promoting callus growth had previously been shown to be an order greater than that of kinetin.2 Characterization.-6-('y,-y-Dimethylallylamino)purine (II): The sample furnished for characterization consisted of 1.7 mg of a bright yellow solid, mp 216-218'.3 Recrystallization from absolute ethanol yielded fine needles, mp 221-223°. Insertion of the picrate sample into the ionizing beam gave a mass spectrum which showed abundant ions, neglecting those due to the picric acid moiety, at m/e 203, 188, 160, 148, 135, 119, and 108. It was noted that the mass spectra of other picrates prepared for comparison4 clearly indicated the molecular ions for picric acid (229) and, in each case, for the ion of the associated base. This finding, which qualifies for more general application, permitted the conclusion that the molecular weight of the basic component of the picrate was 203. The ultraviolet spectra of II(picrate) showed absorption maxima in the 260280-mu region which are not present in the spectra of picric acid taken under the same conditions. A portion of recrystallized picrate was dissolved in ethanol and treated with Dowex-1-HCO3-m When the resin was removed by filtration, the colorless filtrate showed the following ultraviolet maxima: XmaxEtOH 269, 210 my; (acidic) 278; (basic) 276, 285 (sh). These maxima, typical of N6-alkyladenines, indicated that it the compound were indeed an adenine derivative, it would not be substituted at other than the N6-position.5 6 Moreover, the fact that the maxima were at wavelengths lower than those observed for 6-dimethylaminopurine7 suggested that N6 would be monosubstituted. The fragmentation pattern observed in the mass spectrum was consistent with the suggestion that II was an adenine derivative, since similar patterns have been observed for 3-(Qy,7y-dimethylallyl)adenine (triacanthine)8 and for 6-(4-hydroxy-3methyl-trans-2-butenylamino)purine (zeatin) (1),9 particularly the strong peak at m/e 135 due to the adenine ion, C5H5N5+. The side chain was indicated as C5H9 by the difference of 68 mass units between the molecular ion ClOH13N5+ (203) and the adenine ion C5H5N5+. It was noted that, CH3\ /CH2 CHj CHR2 C C NH C3\ / -NH HOCH21 HN~ N CH, HN N> K Nzz N N H H

Cytokinins: identification of compounds isolated from Corynebacterium fascians.