Figure 1
Nitrogen containing heterocycles and their relative distribution among the FDA approved drugs (adapted from reference 2).
Figure 2
Structures of some bestselling drugs containing nitrogen heterocyclic rings.
Figure 3
Structures of some anti-infective heterocyclic drugs.
Figure 4
The four oxadiazole isomers.
Figure 5
Molecular structure of the naturally occurring 1,2,4-oxadiazoles phidianidines A and B, isolated from the aeolid opisthobranch Phidiana militaris.
Figure 6
Annual publications related to oxadiazoles on medicinal chemistry over the period from 1997 to 2017.
2222 Web of Science database, available at https://webofknowledge.com. Keywords: 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,3,4-oxadiazole, 1,2,5-oxadiazole; Filters: Chemistry Medicinal or Pharmacology Pharmacy, accessed in October 2017.
https://webofknowledge.com...
Figure 7
Chemical structures and maximum absorption wavelength values (λmax) for oxadiazoles 11-15. UV data suggest that 1,2,4-oxadiazoles behave as conjugated dienes whereas 1,3,4-oxadiazoles have higher aromatic character.
Figure 8
Addition reaction of n-butyllithium to 3,5-diaryl-1,2,4-oxadiazoles.
Figure 9
Schematic model of the π-π stacking interaction between the oxadiazole derivative 16 and the aromatic aminoacids of the binding site of Mycobacterium tuberculosis mycobacterial enoyl reductase.
Figure 10
Schematic cation-π interaction between the 1,3,4-oxadiazole moiety present in derivative 17 and His279 of the Saccharomyces cerevisiae α-glucosidase.
Figure 11
2D representation of the best binding poses of raltegravir (9, up) in HIV-1 integrase: (a) interaction between the 1,3,4-oxadiazole moiety and the cation Mg2+ linked by two water molecules in a hydrogen bond; (b) oxadiazole core interacting with His114 via a cation-π interaction.
Figure 12
Schematic representation of the 18 derivative forming a hydrogen bond between the 1,2,4-oxadiazole ring and threonine (A) and a π-π stacking with tyrosine via the methoxyphenyl ring (B).
Figure 13
Hydrophobic interaction between Thr179 on the colchicine binding site of bovine tubulin and 1,2,4-oxadiazole derivatives 19a-b.
Figure 9
Schematic model of the π-π stacking interaction between the oxadiazole derivative 16 and the aromatic aminoacids of the binding site of Mycobacterium tuberculosis mycobacterial enoyl reductase.
Figure 10
Schematic cation-π interaction between the 1,3,4-oxadiazole moiety present in derivative 17 and His279 of the Saccharomyces cerevisiae α-glucosidase.
Figure 11
2D representation of the best binding poses of raltegravir (9, up) in HIV-1 integrase: (a) interaction between the 1,3,4-oxadiazole moiety and the cation Mg2+ linked by two water molecules in a hydrogen bond; (b) oxadiazole core interacting with His114 via a cation-π interaction.
Figure 12
Schematic representation of the 18 derivative forming a hydrogen bond between the 1,2,4-oxadiazole ring and threonine (A) and a π-π stacking with tyrosine via the methoxyphenyl ring (B).
Figure 13
Hydrophobic interaction between Thr179 on the colchicine binding site of bovine tubulin and 1,2,4-oxadiazole derivatives 19a-b.
Scheme 1
Classic synthetic routes for obtaining 1,2,4-oxadiazoles: (a) nitrile oxide route; (b) amidoxime route.
Scheme 2
Preparation of 1,2,4-oxadiazoles (18) with anticonculsant profile.
Scheme 3
Synthetic methodology for obtaining symmetrically substituted 1,2,4-oxadiazoles (26) as potential antibacterial agents and corrosion inhibitors.
Scheme 4
1,2,4-Oxadiazoles (29) synthesized under ultrasound irradiation.
Scheme 5
Reaction mechanism for the formation of 1,2,4-oxadiazoles (32) in the presence of IBA-OTf (33).
Scheme 6
Synthesis of 1,2,4-oxadiazoles (39) having antimicrobial and antifungal profiles through the coupling reaction with EDC.HCl.
Scheme 7
Synthesis of 1,2,4-oxadiazoles (43) using the coupling reagent HATU.
Scheme 8
Synthesis of 1,3,4-oxadiazoles (17) with antibacterial activity.
Scheme 9
Synthesis of 1,3,4-oxadiazoles (49) with antiproliferative activity.
Scheme 10
Synthesis of 1,3,4-oxadiazoles (53) under microwave irradiation.
Scheme 11
One-pot preparation of 1,3,4-oxadiazolic derivatives (55) mediated by iodine.
Scheme 12
Synthesis of 1,3,4-oxadiazoles (58), with antimicrobial activity, in the presence of ZnO–TiO2 from hydrazides and aldehydes under microwave irradiation.
Scheme 13
Synthesis of 1,3,4-oxadiazoles (61) and 1,2,4-oxadiazoles (63) with Al3+-K10.
Scheme 14
Synthesis of 1,3,4-oxadiazoles (67) under ultrasound irradiation.
Figure 14
Structures of anthelmintic 1,3,4-oxadiazole derivatives 80a-e and 81a-d.
Table 1
First reported 1,2,4-oxadiazole (68) with anthelmintic activity
Table 2
Structure of 1,2,4-oxadiazoles with nematocidal and taeniacidal activity (69 and 70a-c) and against A. caninum (hookworms) (69)
Table 3
Structure and IC50 values of 1,2,4-oxadiazoles (71, 72a-c) against L. donovani and T. brucei and cytotoxicity to mammalian cell lines (J774, PC3 and Vero, not defined for 72b-c
Table 4
Activity of 71, pentostam and pentamidine against L. donovani in BALB/c mice
Table 5
Chemical structures, IC50 values against trypomastigotes, cytotoxicity against BALB/c mouse splenocytes and GOLD scores for cruzain docking of 1,2,4-oxadiazoles (73a-b)
Table 6
Chemical structure, IC50 values for antiprotozoal assays and cytotoxicity against L6 rat skeletal myoblast cells of novel 1,2,4-oxadiazoles (74a-f)
Table 7
Chemical structure and biological assessment results for antimalarial activity of 1,2,4-oxadiazoles (75a-e)
Table 8
1,3,4-Oxadiazoles 77a-c with reported antimalarial activity
Table 9
Chemical structures and antimalarial (P. falciparum, NF54 and Dd2 strains) results for 1,3,4-oxadiazoles (78a-e)
Table 10
Comparison between the antitrypanosomal activity (T. brucei rhodesiense) of prototype compound 79 and 1,3,4-oxadiazole 80
Table 11
Anthelmintic activity of compounds 81a-e and 82a-d
Table 12
Chemical structures and IC50 values against T. cruzi (epimastigotes, Y strain) of 1,3,4-oxadiazoles (83a-o)
Table 13
Chemical structures of 1,3,4-oxadiazoles (84a-g) with the respective IC50 values against L. major (JISH118), THP-1 and U-937 cell lines and SI values are shown
Table 14
Chemical structures of gold(I) complexes of 1,3,4-oxadiazole-2-thiones (85a-b) along with the respective ligands (86a-b) and in vitro antileishmanial and cytotoxicity results