Design, Synthesis, Biological Evaluation, and Antioxidant and Cytotoxic Activity of Heteroatom-Substituted 1,4-Naphtho- and Benzoquinones.

In the present paper, we report the synthesis, characterization, and biological evaluation as antifungal, antibacterial, antioxidant, and cytotoxic/anticancer agents of N-, S-, O-substituted-1,4-naphtho- and 2,5-bis(amino-substituted)-1,4-benzoquinone derivatives. In the synthesized compounds, antimicrobial activity at low concentrations against Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 bacteria and Candida tenuis VKM Y-70 and Aspergillus niger F-1119 fungi in comparison with controls was identified. 2-(N-Diphenylmethylpiperazin-1-yl)-3-chloro-1,4-naphthoquinone 9a was the most potent, with a minimum inhibitory concentration value of 3.9 µg/mL against test culture M. luteum. The synthesized compounds were screened for their antioxidant capacity using the cupric-reducing antioxidant capacity (CUPRAC) method. 2,2'-[1-(2-Aminoethyl)piperazin-1-yl]-3,3'-dichloro-bis(1,4-naphthoquinone) 10 showed the highest antioxidant capacity, with a 0.455 CUPRAC-trolox equivalent antioxidant capacity (TEAC) coefficient. Other parameters of antioxidant activity (scavenging effects on OH(·), O2(·ï¼), and H2O2) of these compounds were also determined. The cytotoxic activity of the compounds was investigated by employing the sulforhodamine B cell viability assay against A549 (lung), MCF-7 (breast), DU145 (prostate), and HT-29 (colon) cancer cell lines. Compound 10 exhibited the most powerful cytotoxic activity at a concentration of 20 µM against all cell lines. In addition to the strongest antioxidant activity of compound 10, it also had lowest IC50 values (<3 µM), warranting further in vivo studies due to its anticancer activity.

The Synthesis of Novel S-, S,S-, S,S,S-, S,O-, N,S-Substituted Halogenobuta-1,3-dienes.

In this work, thiosubstituted nitrodiene compounds (3, 4a, 5a,b, 6c, 7a, 7c, 9) were obtained from the reactions of some thiols with 2-nitropentachloro-1,3-butadiene. N,S-Substituted nitrodiene compounds (11a-g, 13, 15) were obtained from 2-nitropentachloro-1,3-butadiene and some amines (morpholine and piperazine derivatives). The compound 4a was crystallized in the triclinic crystal system (space group P-1) with the unit cell parameters a = 6.6525(7) Å, b = 10.7906(5) Å, c = 10.8339(4) Å, α = 72.57(3)°, ß = 84.23(4)°, γ = 75.81(3)°, V = 719.03(9) Å3, Z = 2. The novel compounds were characterized by elemental analysis, UV-VIS, FT-IR, 1H-NMR, NMR (13C or APT) and mass spectroscopy.

Synthesis and biological evaluation of novel nitrogen- and sulfur-containing hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents.

1,4-Naphthoquinones are unique reagents in organic synthesis and have been employed in several well known and recently developed areas of application. Furthermore, these 1,4-naphthoquinones have demonstrated high reactivity in nucleophilic vinylic substitutions, in the preparation of sulfurated, (hetero)cyclic and several other transformations. This study describes the synthesis and biological evaluation of derivatives of monosulfurated naphthalene-1,4-dione (3), 3-chloro-2-ethoxy-naphthalene-1,4-dione (4), disulfurated naphthalene-1,4-dione (5), and symmetrical bis-1,4-naphthoquinones (7, 9) were obtained from the reaction of 2,3-dichloro-naphthaquinone (1) with S-, O-substituted mono-, di-, and tetrathiols, respectively. The structures of the novel products were characterized by spectroscopic methods.

2,4,4-Tris(benzyl-sulfan-yl)-1,1-dichloro-3-nitro-buta-1,3-diene.

In the title compound, C(25)H(21)Cl(2)NO(2)S(3), the three phenyl rings are inclined to each other at dihedral angles of 68.4 (1), 79.5 (1) and 37.0 (1)°.