Photoreduction of Sulfite by Spinach Leaf Preparations in the Presence of Grana System

The β-anomer of N⁶-benzyladenosine has been long known as an artificial cytokinin.¹⁾ Recently, however, this compound was isolated from a cytokinin-autotrophic cell culture of anise, Pimpinella anisum L.²⁾ Thus, this compound now constitutes the third member of the naturally-occurring cytokinins possessing an N⁶-benzyladenine structure, together with N⁶-(O-hydroxybenzyl)adenosine isolated from leaves of Poplus robusta³⁾ and N⁶-(o-hy-droxybenzyl)-2-methylthio-9-β-d-glucofuranosyl-adenine isolated from fruits of Zantedeschia aethio-pica.⁴⁾ No information has been available concerning whether or not the a-anomer of N⁶-benzyladenosine possesses cytokinin activity.

We report here the synthesis and cytokinin activity of N⁶-benzyl-α-adenosine (N⁶-benzyl-9-α-d-ribofuranosyl adenine).