L-R4W2

O=C(N)[C@H](CC1=CNC2=C1C=CC=C2)NC([C@H](CC3=CNC4=C3C=CC=C4)NC([C@H](CCCNC(N)=N)NC([C@H](CCCNC(N)=N)NC([C@H](CCCNC(N)=N)NC([C@H](CCCNC(N)=N)N)=O)=O)=O)=O)=O

[1]Planells-Cases R, et, al. Arginine-rich peptides are blockers of VR-1 channels with analgesic activity. FEBS Lett. 2000 Sep 15; 481 (2) : 131-6.|[2]Himmel HM, et, al. The arginine-rich hexapeptide R4W2 is a stereoselective antagonist at the vanilloid receptor 1: a Ca2+ imaging study in adult rat dorsal root ganglion neurons. J Pharmacol Exp Ther. 2002 Jun; 301 (3) : 981-6.