A series of new (1,3,4-oxadiazol-2-yl)-1H-benzo[h]quinolin-4-one derivatives were synthesized, including glucose and xylose hydrazones that were obtained by the reaction of hydrazides with monosaccharides. Cyclization of the sugar hydrazones with acetic anhydride afforded substituted oxadiazoline derivatives. The newly synthesized compounds were evaluated for their antioxidant properties and cytotoxicity, and showed moderate to high activities.A significant part of drug discovery efforts in the past few years has been focused on prevention or treatment of cancer. This is not surprising because in most developed countries, and to an increasing extent, cancer is among the three most common causes of death. Among the five-membered nitrogen heterocycles, 1,3,4-oxadiazoles are associated with a broad spectrum of biological activities. The 1,3,4-oxadiazole ring has been found in the structures of fungicidal, bactericidal, analgesic, antipyretic, antiphlogistic, anticompulsive, anti-inflammatory, paralytic, hypnotic, and sedative agents [1-3]. Several 1,3,4-oxadiazole derivatives have been shown to possess insecticidal, hypoglycemic, hypotensive, antiviral [4], as well as antitumor activities [5]. Certain 1,3,4-oxadiazoline-2(3H)-thiones are known to possess antibacterial, antifungal, antimicrobial, and antiviral activities [4], as well as tyrosinase-inhibiting effect [6]. Nucleosides and their analogs possess a wide range of medicinal properties, including antibiotic, antiviral, and antitumor activity [7][8][9][10][11][12][13][14][15][16]. Consequently, and considering the possible enhancement of biological activity resulting from the attachment of carbohydrate moieties to 1,3,4-oxadiazole heterocycles, our attention was turned to the synthesis of new 1,3,4-oxadiazole derivatives and their nucleoside analogs [17,18].
