Challenging Approach to the Development of Novel Estrogen Receptor Modulators Based on the Chemical Properties of Guaiazulene

Abstract

Tamoxifen, a therapeutic agent for breast cancer, has been associated with genetic polymorphisms in the metabolism of N,N-dialkylaminoethyl substituent, which plays an important role in the expression of selective estrogen receptor modulator (SERM) activity. To solve this problem, we developed a novel estrogen receptor (ER) modulator, Az-01, on the basis of the aromaticity, dipole moment, and isopropyl group of guaiazulene. Az-01 showed four-fold lower binding affinity for ER than E2 but had similar ER-binding affinity to that of 4-hydroxytamoxifen (4-HOtam). Unlike tamoxifen, Az-01 acted as a partial agonist with very weak estrogenic activity at high concentrations when used alone, and it showed potent anti-estrogenic activity in the presence of E2. The cell proliferation and inhibition activities of Az-01 were specific to ER-expressing MCF-7 cells, and no effect of Az-01 on other cell proliferation signals was observed. These findings are important for the development of new types of SERMs without the N,N-dialkylaminoethyl substituent as a privileged functional group for SERMs.

Triazoles in Medicinal Chemistry: Physicochemical Properties, Bioisosterism, and Application

“…41 The 1,4-disubstituted 1,2,3-triazole and 3,4,5trisubstituted 1,2,4-triazole scaffolds tend to become the most common triazole derivatives. 41 2.1. Dipole Moments of Triazoles.…”

“…The physicochemical properties of these four isomers are illustrated in Table . The electrophilic substitution can occur on the ring hydrogens and nitrogen, resulting in a variety of triazole derivatives . The 1,4-disubstituted 1,2,3-triazole and 3,4,5-trisubstituted 1,2,4-triazole scaffolds tend to become the most common triazole derivatives …”