Discadenin‐Derivate ohne cytokininaktiven Δ 2 ‐Isopentenylrest

Discadenine Derivatives without Cytokinine Active Δ 2 ‐Isopentenyl Residue Alkylation of adenine with ethyl 4‐bromo‐2‐ L ‐phthalimidobutyrate yields the N ‐3‐alkylated derivative 4a . After removal of the protecting groups in 4a L ‐(+)‐discadenine without cytokinine active N 6 −Δ 2 ‐isopentenyl residue ( 3a ) is obtained. It shows similar inhibition of the spore germination as L ‐(+)‐discadenine ( 1 ). The derivatives 3b and c with modifications in the N ‐3 side chain are prepared analogously. The p K a value of 5.67 implies that protonation around the physiological pH value plays a key role in the biosynthesis and the regulatory function of discadenine.