Table 1.

Effect of SLs on Ca²⁺ mobilization and ERK1/2 phosphorylation in Jurkat T cells.

Name (Compound Number)	Jurkat T Cells		FPR2-HL60	PMN	Jurkat T Cells	Cyto-Toxicity
	Ca2+ Flux	pERK1/2	Ca2+ flux		[GSH]i
	IC50 (μM)
Arglabin (1) *	11.1 ± 2.7	28.7 ± 6.3	N.A.	N.A.	18.0 ± 1.8	N.T.
α-Epoxyarglabin (1a)	4.4 ± 1.8	32.1 ± 11.5	N.A.	N.A.	(30%)	N.T.
β-Epoxyarglabin (1b)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Pyridinyl arglabin (1c)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Cytisinyl epoxyarglabin (1d)	3.9 ± 1.2	15.4 ± 3.3	N.A.	N.A.	12.4 ± 3.5	N.T.
Anabasinyl epoxyarglabin (1e)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Anabasinyl arglabin (1f)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Argolide (2) *	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
1β,10α-Epoxyargolide (2a)	14.0 ± 3.4	39.4 ± 8.5	N.A.	N.A.	36.1 ± 9.4	N.T.
Cytisinyl argolide (2b)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Dihydroargolide (2c)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Grosheimin (3) *	15.4 ± 4.3	43.0 ± 7.5	N.A.	N.A.	16.6 ± 4.8	N.T.
Chloroacetate grosheimin (3a)	6.0 ± 2.1	7.8 ± 2.9	13.2 ± 3.4	10.1 ± 2.8	3.8 ± 1.4	12.3 ± 3.6
Cytisinyl grosheimin (3b)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
3β-Hydroxyarhaline (4) *	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.
Epoxyarhaline (4a)	N.A.	N.A.	N.A.	N.A.	N.A.	N.T.

Inhibitory activity was evaluated after a 20 min pretreatment with various concentrations of the indicated compounds at room temperature, followed by the addition of 10 µg/mL anti-CD3/CD28 (pERK1/2 in Jurkat cells), 10 µg/mL anti-CD3 (Ca²⁺ flux in Jurkat cells), 5 nM fMLF [Ca²⁺ flux in human neutrophils (PMN)], or 5 nM WKYMVM (Ca²⁺ flux in FPR2-HL60 cells). N.A. (no activity) or N.T. (no toxicity) was observed at all concentrations tested (5.125, 6.25, 25, and 50 µM). Percent inhibition is indicated at 50 µM of SLs if full inhibition was not observed at the highest tested concentration (50 µM) in the GSH assay. * Activities for parent compounds were taken from Reference [6].