. Author manuscript; available in PMC: 2017 Mar 21.

Published in final edited form as: Biochem Pharmacol. 2011 Aug 6;82(11):1673–1681. doi: 10.1016/j.bcp.2011.07.099

Table 1.

Potencies and efficacies of FS and FS analogs on recombinant ACs 1, 2 and 5 in the presence of 7 mM Mg²⁺.

Mg²⁺	AC1		AC2		AC5
Diterpene	EC₅₀ [μM]	Efficacy [%]	EC₅₀ [μM]	Efficacy [%]	EC₅₀ [μM]	Efficacy [%]
FS^{(+++, xxx)}	5.5 ± 0.8^*	100	47.3 ± 8.1	100	4.6 ± 1.5^*	100
DMB-FS^{(b, cc)}	2.5 ± 0.8	105 ± 9^**	80.3 ± 54.1	93.5 ± 1.7^*	26.2 ± 11.1	190.4 ± 42.6^*
6A7DA-FS^{(##, xx, a, b, ccc)}	6.5 ± 2.1	62.5 ±5.9^**	EC_{50_}1: 1.8 ± 5.5 EC₅₀_2: 61.2 ± 28.6^***	22.9 ± 1^**	52.1 ± 16.7^*	99.6 ± 11.3^*
7DA-FS^{(+++, ##, xxx)}	15.8 ± 4.2	95.0 ± 3.4^*	647 ± 8.5^***	101.9 ± 17.2^*	262.5 ± 55.9^*	103.3 ± 11.1
9d-FS^{(+, c)}	16.8 ± 3.0	103.5 ± 17.1	242 ± 113	79.5 ± 10.9^**	77.8 ± 46.1	138.1 ± 27.0
1d-FS^(c)	Ineffective	11.1 ± 4.7	Ineffective	1.7 ± 3.4	Ineffective	14.7 ± 4.4^*
BODIPY-FS^{(###, xxx, aaa, ccc)}	0.9 ± 0.2	18.7 ± 2.5	0.5 ± 0.04^**	−115.9 ± 17.5^***	23.6 ± 4.2^**	13.7 ± 1.7^***

AC activities were determined as described in “Materials and Methods”. Reaction mixtures contained 7 mM Mg²⁺, [α–³²P]ATP (0.3 μCi/tube), 10 μM GTPγS, 100 μM cAMP, 0.4 mg/mL creatine kinase, 9 mM phosphocreatine, 100 μM IBMX and diterpenes at concentrations from 100 nM – 300 μM. Data were analyzed by non-linear regression to determine the EC₅₀-values. The efficacy for each analog was determined by dividing the maximal stimulation obtained for the analog by the maximum stimulation obtained by treatment with 300 μM FS expressed in percent. Significant impacts of the different metal ions on EC₅₀- or E_max-values were analyzed using the Student’s t test. Statistical significance between the data of Table 1 and 2 is shown by (^*) p < 0.05, (^**) p < 0.005 and (^***) p < 0.0001. Statistical differences between the examined AC isoforms were analyzed by ANOVA Bonferroni test. Comparison of EC₅₀-values: AC1 vs. AC2 (⁺) p < 0.05, (⁺⁺) p < 0.005 and (⁺⁺⁺) p < 0.0001; AC1 vs. AC5 (^#) p < 0.05, (^##) p < 0.005 and (^###) p < 0.0001; AC2 vs. AC5 (^x) p < 0.05, (^xx) p < 0.005 and (^xxx) p < 0.0001. Comparison of E_max-values: AC1 vs. AC2 (^a) p < 0.05, (^aa) p < 0.005 and (^aaa) p < 0.0001; AC1 vs. AC5 (^b) p < 0.05, (^bb) p < 0.005 and (^bbb) p < 0.0001; AC2 vs. AC5 (^c) p < 0.05, (^cc) p < 0.005 and (^ccc) p < 0.0001.