Special Issue "Development and Synthesis of Biologically Active Compounds"

The intention of this Special Issue is to focus on new achievements in the design, preparation, and in vitro and in vivo biological evaluation of bioactive molecules that can result in the development of natural or artificial potent compounds looking for promising pharmaceuticals and agrochemicals [...].

Application of Pluronics for Enhancing Aqueous Solubility of Lipophilic Microtubule Destabilizing Compounds on the Sea Urchin Embryo Model

In screening, the dilution of DMSO stock solution of a lipophilic molecule with an assay medium often causes compound precipitation. To overcome the issue, the application of Pluronics as cosolvents was examined using a phenotypic sea urchin embryo assay that allows for the quick and facile evaluation of the antiproliferative effect together with systemic toxicity. Maximum tolerated concentration values for Pluronics L121, P123, and F127 were 1.4 μM, 8.6 μM, and 39.7 μM, respectively, and correlated directly with their hydrophilicity. Pluronics L121 and P123 suppressed cleavage and blastomeres retained the round shape, unlike hydrophilic Pluronic F127, which induced fertilization envelope creasing and embryo deformation that could be associated with the interaction of hydrophilic PEO units with mucopolysaccharides at the surface of sea urchin embryos. The toxicity of P123, but not of L121 and F127, was temperature-dependent and markedly increased at lower temperatures. CMC values obtained at different temperatures confirmed that the toxic effect of P123 was associated with both unimers and micelles, whereas F127 toxicity was related mainly to micelles. Evaluation using phenotypic sea urchin embryo assay revealed that potent microtubule destabilizers, namely albendazole, diarylisoxazole, and two chalcones, retained antimitotic activity after the dilution of their DMSO or 2-pyrrolidone stock solutions with 1.25% w/v Pluronic P123 or 5% w/v Pluronic F127. It was suggested that Pluronic P123 and Pluronic F127 could be used as cosolvents to improve the solubility of lipophilic molecules in aqueous medium.

Preparation of Ring-Methoxylated Arylnitromethanes by the Victor Meyer Reaction

Easily accessible and stable ring-methoxylated benzyl chlorides react with AgNO2 to give mixtures of the corresponding arylnitromethanes and nitrite esters. A modified approach for the isolation of arylnitromethanes is described, which represents a valuable improvement of the established Victor Meyer reaction. The isolation technique, which involves reaction of the nitrite ester with urea in methanol, allows the desired arylnitromethanes to be isolated, without loss, in 29–75% yields, and generates the corresponding recyclable benzyl alcohols. Unexpectedly, ring-methoxylated benzyl iodides cannot be used because they are not sufficiently stable and produce tars under the developed reaction conditions.

Efficient Synthesis of Glaziovianin A Isoflavone Series from Dill and Parsley Extracts and Their in Vitro/in Vivo Antimitotic Activity

A concise six-step protocol for the synthesis of isoflavone glaziovianin A (GVA) and its alkoxyphenyl derivatives 9 starting with readily available plant metabolites from dill and parsley seeds was developed. The reaction sequence involved an efficient conversion of the key intermediate epoxides 7 into the respective β-ketoaldehydes 8 followed by their Cu(I)-mediated cyclization into the target series 9. The biological activity of GVA and its derivatives was evaluated using a panel of seven human cancer cell lines and an in vivo sea urchin embryo assay. Both screening platforms confirmed the antimitotic effect of the parent GVA (9cg) and its alkoxy derivatives. Structure-activity relationship studies suggested that compounds 9cd and 9cf substituted with trimethoxy- and dillapiol-derived B-rings, respectively, were less active than the parent 9cg. Of the evaluated human cancer cell lines, the A375 melanoma cell line was the most sensitive to the tested molecules. Notably, the target compounds were not cytotoxic against human peripheral blood mononuclear cells up to 10 μM concentration. Phenotypic readouts from the sea urchin assay unequivocally suggest a direct microtubule-destabilizing effect of isoflavones 9cg, 9cd, and 9cf.