Cycloleucine is a specific inhibitor of S-adenosyl-methionine mediated methylation. Cycloleucine is antagonist of NMDA receptor associated glycine receptor, with a Ki of 600 μM. Cycloleucine is also a competitive inhibitor of ATP: L-methionine-S-adenosyl transferase in vitro. Cycloleucine has anxiolytic and cytostatic effects[1][2][3][4].

Cycloleucine (4-40 mM; 3 h) blocks internal methylation of viral RNA in B77 transformed chick embryo fibroblasts[5].Cycloleucine (40 mM; 24 h) blocks the formation of both m6A and the penultimate Gm in B77 38S RNA subunits by greater than 90%[5].Cytostatic (10 µg/mL) inhibits the viability human KB and mouse L1210s leukemia cell lines[5].

Cycloleucine (0.5-4 µg; intracerebroventrical injection) increases time spent in open arms, open arm entries, and extreme arrivals in rats[3]. Animal Model: Male rats bilaterally cannulated into the nucleus accumbens septi (NAS)[3]

[1]. Hood WF, et, al. 1-Aminocyclobutane-1-carboxylate (ACBC): a specific antagonist of the N-methyl-D-aspartate receptor coupled glycine receptor. Eur J Pharmacol. 1989 Feb 28;161(2-3):281-2. [2]. Caboche M, et, al. RNA methylation and control of eukaryotic RNA biosynthesis. Effects of cycloleucine, a specific inhibitor of methylation, on ribosomal RNA maturation. Eur J Biochem. 1977 Mar 15;74(1):19-29. [3]. Gargiulo API, et, al. Effects of Cycloleucine in the Nucleus Accumbens Septi on the Elevated plus Maze Test in Rats. Neuropsychobiology. 2020;79(3):191-197. [4]. Du? D, et, al. Cytostatic activity in vitro of cycloleucine, aspartic acid and glutamic acid phosphonic analogues. Arch Immunol Ther Exp (Warsz). 1980;28(3):433-8. [5]. Dimock K, et, al. Cycloleucine blocks 5'-terminal and internal methylations of avian sarcoma virus genome RNA. Biochemistry. 1978 Aug 22;17(17):3627-32.