ABSTRACT
A series of flavanols were synthesized to assess their biological activity against human non-small cell lung cancer cells (A549). Among the sixteen synthesized compounds, it was observed that compounds 6k (3.14 ± 0.29 µM) and 6l (0.46 ± 0.02 µM) exhibited higher potency compared to 5-fluorouracil (5-Fu, 4.98 ± 0.41 µM), a clinical anticancer drug which was used as a positive control. Moreover, compound 6l (4'-bromoflavonol) markedly induced apoptosis of A549 cells through the mitochondrial- and caspase-3-dependent pathways. Consequently, compound 6l might be developed as a candidate for treating or preventing lung cancer.
Subject(s)
Antineoplastic Agents , Apoptosis , Flavonols , Humans , Flavonols/pharmacology , Flavonols/chemical synthesis , Flavonols/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , A549 Cells , Caspase 3/metabolism , Cell Proliferation/drug effects , Structure-Activity Relationship , Molecular Structure , Fluorouracil/pharmacology , Mitochondria/drug effects , Mitochondria/metabolism , Drug Screening Assays, Antitumor , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/metabolism , Cell Line, TumorABSTRACT
In this paper, the syntheses of twelve asymmetric curcumin analogs using Pabon's method are reported. Generally, the previously reported yields of asymmetric curcuminoids, such as 9a (53%), 9c (38%), and 9k (38%), have been moderate or low. Herein, we propose that the low yields were due to the presence of water and n-BuNH2 in the reaction media. To prove this formulated hypothesis, we have demonstrated that the yields can be improved by adding molecular sieves (MS) (4 Å) to the reaction mixture, thus reducing the interference of water. Therefore, improved yields (41-76%) were obtained, except for 9b (36.7%), 9g (34%), and 9l (39.5%). Furthermore, compounds 9b, 9d, 9e, 9f, 9g, 9h, 9i, 9j, and 9l are reported herein for the first time. The structures of these synthetic compounds were determined by spectroscopic and mass spectrometry analyses. The free radical scavenging ability of these synthetic asymmetric curcuminoids was evaluated and compared to that of the positive control butylated hydroxytoluene (BHT). Among the synthesized asymmetric curcuminoids, compounds 9a (IC50 = 37.57 ± 0.89 µM) and 9e (IC50 = 37.17 ± 1.76 µM) possessed effective 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging abilities, and compounds 9h (IC50 = 11.36 ± 0.65 µM) and 9i (IC50 = 10.91 ± 0.77 µM) displayed potent 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging abilities comparable to that of curcumin (IC50 = 10.14 ± 1.04 µM). Furthermore, all the synthetic asymmetric curcuminoids were more active than BHT.
