Table 2.

LAT1 trans-stimulation and cis-inhibition cell assay activity for some naturally occurring amino acids and structural analogs including benzotriazole 13.^a

Compound	R	Relative %Efflux	% Inhibition	IC50 (μM)
14 (L-Arg )	NH2(NH)CNH(CH2)2−	28	49
15 (L-His)		140	92	110 ± 93
16		85	70	190 ± 25
17		81	74	170 ± 53
18 (L-Phe)		100	85	69 ± 29
19		140	84	160 ± 56
20		130	98	69 ± 17
21		89	99	100 ± 53
22 (L-Trp)		59	79	160 ± 87
13 (L-Trp)		100	59	340 ± 104

^aCell assay conditions were as described for Table 1.