TABLE 4.

Activities of selected mixtures of the bicyclic guanidine PS-SCL against C. neoformans

Building block	IC50 (μg/ml)	MIC (μg/ml)
R1 defined
4-t-Butyl-cyclohexanecarboxylic acid	2.3 ± 0.03	4–8
1-Adamantaneacetic acid	2.0 ± 0.52	4–8
Acetic acid	37 ± 9.4	50–62
R2 defined
l-Cyclohexylalanine	6.4 ± 0.26	16–32
d-Cyclohexylalanine	6.3 ± 0.46	8–16
l-Cyclohexylglycine	6.2 ± 0.35	16–32
d-Cyclohexylglycine	8.7 ± 0.21	16–32
d-Leucine	17 ± 1.19	32–62
l-Phenylalanine	15 ± 0.23	16–32
R3 defined
l-Cyclohexylalanine	5.4 ± 0.14	8–16
d-Cyclohexylalanine	4.1 ± 2.07	8–16
d-Cyclohexylglycine	5.7 ± 1.35	8–16
l-Cyclohexylglycine	6.7 ± 1.05	16–32
l-Phenylalanine	10 ± 3.70	16–32