An efficient approach to novel 17-5′-(1′,2′,4′)-oxadiazolyl androstenes via the cyclodehydration of cytotoxic O-steroidacylamidoximes, and an evaluation of their inhibitory action on 17α-hydroxylase/C17,20-lyase

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

“…There are several methods for the preparation of 1,2,4-oxazoles starting from compounds bearing carboxyl function. Because of the well-known sensitivity of constrained bicyclic monoterpenes, however, a pathway with mild reaction condition was applied in our case [ 26 ]. Carboxylic acids 1 and 2 were coupled with amidoximes in the presence of CDI in DCM with excellent yields, followed by TBAF-catalyzed ring closure of O -acylated amidoximes 3 – 5 at room temperature.…”

“…Since several steroid-based 1,2,4- and 1,3,4-oxadiazoles as well as their amidoxime type intermediates have shown exerting antiproliferative action on adherent human cancer cell lines [ 25 , 26 , 34 ], antiproliferative activities of the prepared analogues were also tested against a panel of human malignant cell lines isolated from cervical (HeLa), ovarian (A2780), and breast (MCF7 and MDA-MB-231) cancers ( Table 2 ). O -Acylated amidoximes ( 3 – 5 ) exhibited remarkable growth inhibitory activities with calculated IC 50 values comparable to those of reference agent cisplatin.…”

“…On the other hand, 1,2,4- and 1,3,4-oxadiazoles have also been extensively studied in the past decade [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. A wide range of biologically active pharmacophores possess these five-membered heteroaromatic ring systems with remarkable biological properties including sphinosine kinase inhibitor [ 29 ], diacylglycerol acyltransferase 1 (DGAT-1) inhibitor [ 30 ], glycogen synthase kinase (GSK-3) inhibitor [ 31 ], sirtuin (SIRT) inhibitor [ 32 ] and methionine aminopeptidase inhibitor activities [ 33 ].…”

“…A wide range of biologically active pharmacophores possess these five-membered heteroaromatic ring systems with remarkable biological properties including sphinosine kinase inhibitor [ 29 ], diacylglycerol acyltransferase 1 (DGAT-1) inhibitor [ 30 ], glycogen synthase kinase (GSK-3) inhibitor [ 31 ], sirtuin (SIRT) inhibitor [ 32 ] and methionine aminopeptidase inhibitor activities [ 33 ]. Some diterpenic 1,2,4- and 1,3,4-oxadiazoles, including steroid-based compounds, have also shown remarkable antiproliferative action on adherent human cancer cell lines [ 25 , 26 , 34 , 35 , 36 , 37 ].…”

Antihormonal potential of selected D-homo and D-seco estratriene derivatives

“…Inhibitory effects exerted on the C 17,20 -lyase activity were determined by an in vitro radiosubstrate incubation method described in other publications [33,34]. In brief, adult Wistar rat testicular tissue was homogenized with an Ultra-Turrax in 0.…”