b-leucine

3-Amino-4-methylpentanoic acid (DL-Homovaline) is a beta-amino acid that is pentanoic acid substituted at positions 3 and 4 by amino and methyl groups respectively. It has a role as a human metabolite.

Bestatin (Ubenimex) competitively inhibits many aminopeptidases, including B, N and leucine aminopeptidases. Ubenimex is a microbial metabolite and dipeptide with potential immunomodulatory and antitumor activities. Aminopeptidases has been implicated in the process of cell adhesion and invasion of tumor cells. Therefore, inhibiting aminopeptidases may partially attribute to the antitumor effect of ubenimex. This agent also activates T lymphocyte, macrophage, and bone marrow stem cell as well as stimulates the release of interleukin-1 and -2, thus further enhances its antitumor activity.

Ansatrienin B is an ansamycin antibiotic and antifungal agent first isolated from S. collinus and S. rishiriensis. Ansatrienin B inhibits parathyroid hormone-induced calcium release in fetal rat long bones (IC50 = 21 nM), pp60c-src kinase (IC50 = 50 nM), and protein synthesis via L-leucine incorporation inhibition (IC50 = 58 nM in A549 cells), and also suppresses TNF-α-induced ICAM-1 expression (IC50 = 300 nM). Ansatrienin B is used in biochemical and pharmacological research systems to investigate translation inhibition, kinase signaling modulation, bone resorption pathways, and inflammatory adhesion molecule regulation in cellular and organotypic models.

Evofolin B is a natural compound isolated from the stem bark of Zanthoxylum ailanthoides. Evofolin B has an inhibitory effect on the superoxide anion produced by human neutrophils in response to formyl-L-methionine-L-leucine-L-phenylalanine/cytochalasin B (fMLP/CB).