Table 1.

Summary of HSL IC₅₀s of Cyclipostins and Analogs^a

Compound	Structure	Tail	Diastereomer	IC50 [μM]	Published synthesis
Synthetic Cyclophostin 1a		1	Trans	>100	[27]
Natural Cyclophostin 1b		1	Cis	>100	[27]
Cyclophostin Phosphonate analog 2a		1	Trans	100	[7]
Cyclipostin R 3a		15	Trans	0.9±0.9	This work
Cyclipostin R 3b		15	Cis	0.075±0.025	This work
Cyclipostin P 4a		16	Trans	0.025±0.015	[27]
Cyclipostin P 4b		16	Cis	0.42±0.16	[27]
Cyclipostin R Phosphonate 5a		15	Trans	0.45 ± 0.25	This work
Cyclipostin R Phosphonate 5b		15	Cis	0.47 ± 0.38	This work
Cyclipostin P Phosphonate 6a		16	Trans	6.9 ± 2.4	This work
Cyclipostin P Phosphonate 6b		16	Cis	0.36 ± 0.34	This work
14		16		0.06±0.02	This work
8		16		0.54±0.4	[26]
16		16		>100	This work
9aa		10	Cis	40	[26]
10a		12	Cis	35	[26]
10b		12	Trans	13.5	[26]
11a		16	Cis	~60	[26]
11b		16	Trans	~10	[26]
12a		18	Cis	>100	[26]
12b		18	Trans	~27	[26]

^aIC₅₀s, the concentration at which the enzyme is inhibited 50% of the control activity, was obtained using triolein as a substrate as described in Experimental. Graphical abstract