. 2023 Jan 23;8(5):5050–5056. doi: 10.1021/acsomega.2c07861

Table 2. Aspartimide Formation in Other Aspartimide-Prone Peptide Sequences.

Cpd. sequence^a	Fmoc deprotection reagent^b	crude yield^c(%)	product ratio^d (%)
hexapeptide 2 GDGAKF	20% PPR	41	67/32/1
	25% DPA	49	84/8/8
hexapeptide 3 VKDRYI	20% PPR	40	84/8/8
	25% DPA	43	90/4/6
hexapeptide 4 GDRAKF	20% PPR	51	96/3/1
	25% DPA	63	99/0/1
hexapeptide 5 VKDCYI	20% PPR	53	90/5/5
	25% DPA	48	88/4/8
hexapeptide 6 VKDAYI	20% PPR	55	97/1/2
	25% DPA	51	96/1/3

One-letter code for amino acids. C-termini are carboxamide.

SPPS was carried at 60 °C. PPR, piperidine; DPA, dipropylamine. Percentages (%) are in v/v.

Crude yield is calculated as explained in Table 1.

Product ratio was determined by LC analysis and is given as follows: % desired product/% aspartimide/% other byproducts.