Antifungal quinazolinones from marine-derived Bacillus cereus and their preparation.
ABSTRACT Two new quinazolinones alkaloids, R(+)-2-(heptan-3-yl)quinazolin-4(3H)-one (1) and (2R,3'R)+(2S,3'R)-2-(heptan-3-yl)-2,3-dihydroquinazolin-4(1H)-one (2) (a pair of epimers), as well as seven known analogues, 2-methylquinazolin-4(3H)-one (3), 2-benzylquinazolin-4(3H)-one (4), cyclo-(Pro-Ile), cyclo-(Pro-Leu), cyclo-(Pro-Val), cyclo-(Pro-Phe), and cyclo-(Tyr-Pro) were isolated from the n-butyl alcohol extract of the marine-derived bacterium Bacillus cereus 041381. The new compounds were identified by spectroscopic analysis and chemical synthesis. Four optical isomers 5-8 were also synthesized. Compounds 1-8 all showed moderate antifungal activity against Candida albicans with MIC values of 1.3-15.6 μM. Compound 5 exhibits the most powerful antifungal activity, which may reveal that S-configuration and 2,3-double bond were necessary for antifungal activity, and the racemization at C-2 and C-3' reduced the antifungal activity.
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ABSTRACT: Novel thiazole, pyrimidine and benzylidene derivatives derived from quinazoline scaffold have been synthesized. The antitumor evaluation of the newly synthesized products against three cancer cell lines namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460), and CNS cancer (SF-268) showed that the benzylidene–quinazoline derivative 12a showed remarkable activity against all three cell lines. The thiazolo-quinazoline derivative 10 showed greater activity than the control against breast adenocarcinoma (MCF-7) with a concentration of 0.01 μM. Moreover, the antileishmanial activity of the newly synthesized products tested on Leishmania donovani amastigotes showed that compounds 4, 14, and 18 had very promising activity.Medicinal Chemistry Research 22(5). · 1.61 Impact Factor