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Derivatives of adenosine 3',5'-cyclic phosphate (cAMP) with modifications in both the 2' and the 8 positions were synthesized and their enzymic activities as activators of cAMP-dependent protein kinase and as substrates for and inhibitors of cAMP phosphodiesterases were determined. Three types of derivatives were investigated: 8-substituted derivatives of O2'-Bt-cAMP, 8-substituted derivatives of 9-beta-D-arabinofuranosyladenine 3',5'-cyclic phosphate (ara-cAMP), and 8-substituted derivatives of 8,2'-anhydro-9-beta-D-arabinofuranosyladenine 3,'5'-cyclic phosphate (8,2'-anhydro-cAMP). The 8-substituted O2'-Bt-cAMP derivatives were synthesized by acylation of the preformed 8-substituted cAMP (8-HS-cAMP, 8-MeS-cAMP, and 8-PhCH2S-cAMP). 8-Br-O2'-tosyl-cAMP was sued as an intermediate for the preparation of 8,2'-anhydro-cAMP derivatives (8-HO-, 8-SH-, 8-H2N-, and 8-H3 CHN derivatives of 8,2'-anhydro-cAMP). 8-Substituted ara-cAMP derivatives were obtained by ring opening of 8-HO-8,2'-anhydro-cAMP with H+/H2O, NH3/MeOH, or MeONa/MeOH (to yield the 8-HO-, 8-H2N-, and 8-MeO-ara-cAMP derivatives). All of these doubly modified derivatives of cAMP are less than one-hundredth as active as cAMP at activating protein kinase and did not serve as substrates for the phosphodiesterase. These data show that the general inactivity of 2' derivatives of cAMP with kinase was not overcome by addition of an 8-substituent, even though many 8-substituted derivatives of cAMP activate the kinase more efficiently than does cAMP itself. In addition they show that while 2'-modification were tolerated by the phosphodiesterase, addition of an 8-substituent countermanded the allowable 2'-modification. The 8-substituted derivates of 02'-Bt-cAMP were found in general to be slightly better inhibitors of phosphodiesterase than the parent compounds containing no o2'-Bt substitution. As a group, the 8-substituted ara-cAMP derivatives were poorer inhibitors of phosphodiesterase than 8-substituted cAMP derivatives while the 8,2'-anhydro-cAMP derivatives were much poorer inhibitors than the 8-substituted ara-cAMP derivatives.
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
June 1971,
Biochemistry,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
October 1971,
Biochemical and biophysical research communications,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
March 2008,
Journal of medicinal chemistry,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
February 1973,
Biochemistry,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
June 1980,
Chemical & pharmaceutical bulletin,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
December 1973,
Biochemistry,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
January 1974,
Methods in enzymology,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
February 1980,
Experientia,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
September 1971,
Biochemistry,
T A Khwaja, and
K H Boswell, and
R K Robins, and
J P Miller
October 1973,
Journal of medicinal chemistry,
