Table 1.

The sequences and minimum inhibitory concentrations and fold changes for Api-137, the C-terminal leucine carboxylic acid modified derivatives (* = decarboxy; ** = primary alcohol), and the Arg17 modifications.

Peptide	Sequence	Unnatural Amino Acid	MIC (μM)	Fold change
Api-137	gu-ONNRPVYIPRPRPPHPRL-OH	none	0.16–0.3	1
1	gu-ONNRPVYIPRPRPPHPrL-OH	r = homoarginine	2.5	16
2	gu-ONNRPVYIPRPRPPHPrL-OH	r = citrulline	20	128
3	gu-ONNRPVYIPRPRPPHPRL-OH	R = mono-methyl arginine	0.3	1
4	gu-ONNRPVYIPRPRPPHPRl-*	l = decarboxy leucine	>40	>800
5	gu-ONNRPVYIPRPRPPHPRl-**	l = l-leucinol	5	32
6	gu-ONNRPVYIPRPRPPHPRl-**	l = d-leucinol	10–20	62–128
7	gu-ONNRPVYIPRPRPPHPRf-**	f = l-phenylalaninol	5	32
8	gu-ONNRPVYIPRPRPPHPRf-**	f = d-phenylalaninol	40	800