Cyclo(Pro-Gly) is an active metabolite of piracetam-N-phenylacetyl-L-prolylglycine (GWS-111), it shows a greater resistance to an enzymatic effect than natural neuropeptides. Cyclo-(Gly-Pro) shows cytotoxicity at the concentration of 10 umol/L, it inhibits the growth of Bacillus subtilis with the minimal inhibitory concentration (MIC) value of 0.8, 0.8 g/L.

Interiorin can be isolated from Kadsura heteroclita and has moderate anti-HIV activity with an EC50 value of 1.6 lg/mL.

[Sar1, Ile8]-Angiotensin II is a peptide that has multiple effects on vascular smooth muscle, including contraction of normal arteries and hypertrophy or hyperplasia of cultured cells or diseased vessels. The biological activities of angiotensin II antagonists upon basal and angiotensin II-stimulated aldosterone production were evaluated in an isolated canine glomerulosa cell preparation.