Exploration of Drug Science

Table 2

Scope of the C-terminal amino acids in conversion to carboxylic acids

Entry	Xaa	Product	HPLC purity of 2 (%)^a
Entry	Xaa	Product	Oxone	BME
1	Gly	2a	84	82
2	Ala	2b	82	82
3	Val	2c	77	76
4	Ile	2d	63	61 (74)^b
5	Leu	2e	80	79
6	Phe	2f	87	89
7	Pro	2g	77	65 (87)^b
8	Ser	2h	82	81
9	Thr	2i	81	91
10	Glu	2j	81	95
11	Cys	2k	< 1	66
12	Cys(Acm)	2k’	< 1	-
13	Met	2l	< 1	80
14	Tyr	2m	81	87
15	His	2n	81	85
16	Lys	2o	76	75
17	Arg	2p	84	60
18	Trp	2q	< 1	86

^a detected at 220 nm; ^b after the addition of BME, a 20 h reaction was performed. -: not examined