Benzyl adenine

B-i = Benzylated Adenine, B2 = Thymine Bi = Benzylated Cytosine, B2 = Thymine Z = Dimethyl Triptophan, B- = B2 = Thymine... 

Indications about ultraviolet absorption spectra of these compounds reproduced in Table IX are less clear-cut. The predicted wavelengths for the amine forms are increasing in the order N(9)H < N(7)H[Pg.117]

Thus in dimethylacetamide, methylation of 1-methyladenine with methyl p-toluenesul-fonate to give 1,9-dimethyladenine required 125 C/2 h whereas benzylation of 1-benzyl-adenine occurred at room temperature over 70 h (65JHC291). 

Cytokinins are cell division promoting hormones. Highly active cytokinins include kinetin, (4-1), trans zeatin (4-2), N -isopentenyl adenine (4-3) and benzyl adenine (4-4). 

Hydrogen bonding to the hydrogen acceptor site (B, Fig. 6a), is not critical for activity. Replacement of the nitrogen by oxygen, methylene or sulphur is possible with retention of some activity, and the styryl analogue (4-8) is almost as active as benzyl adenine. 

C. are synthesized mainly in the roots of higher plants and they are not subject to much translocation. It is interesting that they occur in certain transfer RNA molecules 0.05 to 0.1 % of the purine bases in tRNA have cytokinin activity. In E. coli, the tRNA species for phenylalanine, leucine, serine, tyrosine and tryptophan contain C. N -(y,y -dimethylallyl)-Adenosine (see) also occurs in the free form. The most important C. are Kinetin (see), Zeatin (see) and Dihydrozeatin (see). The synthetic C, A-benzyl-adenine (see 6-Benzylaminopurine) and SD 8339 (Fig. 2) also have high cytokinin activity. 

Zeatin riboside Benzyl adenine Zeatin-7-glucoside Napthaleneacetic acid Sodium docedyl sulphate Polyacrylamide gel electrophoresis Isoelectric focusing... 

Leaf and root explants from axenically grown seedlings of L fendleri regenerate shoots profusely on MS medium with 3% sucrose and 1 mg/L each of benzyl adenine and zeatin. These explants were cocultivated Agrobacterium tumefaciens harbouring a binary transformation vector whose T-DNA carries genes conferring resistance to either the herbicide L-phosphinothricin (L-PPT) or to kanamycin. 

Adenosine deaminase (0.5-200 itM), purified from calf intestinal mucosa, in 0.2 M sodium phosphate at pH 8, containing 10% dimethyl sulfoxide (v/v), is treated at 37° in the dark with 9-(p-bromoacetamido-benzyl) adenine (0.01-5 mAf). The alkylating reagent is added dissolved in dimethyl sulfoxide. When necessary, the pH of the reaction mixture is maintained constant by addition of 1.0 A NaOH. At intervals 5-10 / samples are removed and diluted in 0.1 M sodium phosphate at pH 7.5 adenosine deaminase activity is measured. The enzyme activity is determined by the method of Kalckar with adenosine as substrate by following the decrease in absorbance at 265 nm in 0.1 Af sodium phosphate at pH 7.5. 

---