Table 2.

Structures and CE inhibition data for tanshinones and their respective synthetic anhydrides.

ID	Compound	Structure	hCE1 (o-NPA)		hiCE (o-NPA)		IC50 (nM) ± SE
			Ki ± SE (nM)	Fold increase in potencya	Ki ± SE (nM)	Fold increase in potencya	hAChE [% Inhibition at 10μM]	hBChE [% Inhibition at 10μM]
1b	Tanshinone I		26,250 ± 1,730	NAc	14,550 ± 1,560	NA	>10,000 [10]	>10,000 [6]
2	Tanshinone I anhydride		2.4 ± 0.49	10,937	0.82 ± 0.16	17,744	>10,000 [47]	>10,000 [32]
3b	Tanshinone IIA		6,890 ± 424	NA	2,450 ± 369	NA	>10,000 [4]	>10,000 [1]
4	Tanshinone IIA anhydride		1.9 ± 0.41	3,626	1.4 ± 0.49	1,750	3,312 ± 715 [65]	7,883 ± 2,237 [38]
5b	Dihydro-tanshinone		398 ± 66	NA	118 ± 21	NA	1,950 ±381 [84]	>10,000 [5]
6	Dihydro-tanshinone anhydride		3.6 ± 0.79	111	0.61 ± 0.14	193	10,132 ± 3,358 [66]	7,823 ± 3,866 [61]
7b	Crypto-tanshinone		544 ± 64	NA	141 ± 23	NA	6,410 ± 1,160 [44]	>10,000 [1]
8	Crypto-tanshinone anhydride		2.8 ± 0.46	194	0.75 ± 0.16	188	3,213 ± 711 [68]	2,844 ± 694 [69]

^a– Increase in potency is compared to the parent tanshinone.

^b– The Ki values for 1, 3, 5 and 7 have been previously reported¹³, but are included here for comparative purposes..

^c– NA - Not applicable