The generation of mathematical models through the quantitative relationship between the chemical structure and the biological activity (QSARs) of compounds was used in this investigation. Mathematical models were generated from compounds available in literature that predicting the biological activity against SARS-CoV-2. The data indicate that the parameters that most interfere and allow to validate the equations are: number of hydrogen bonding donors, maximum projection radius and length perpendicular to the minimum area. This allows us to infer that there is synergism between the basic capacity of the cysteine protein action site present in the virus and the geometric conditions for the three-dimensional alignment to potential compounds with anti-SARS-CoV-2 action. The authors highlight that mathematical models assist in chemical research, but do not replace evaluation of the efficacy in vitro, in vivo, pre-clinical and clinical studies, which are essential for dosage, release or authorization to use any medication or supplement.

Cyclodextrins (CDs) are cyclic oligosaccharides comprised of six or more glucose units connected by alpha-1,4 bonds. They have hydrophobic cavities with a hydrophilic exterior, and are versatile receptors for a variety of substrates. This ability allows them to be applied in many fields, as distinct as supramolecular chemistry, nanotechnology, pharmaceuticals, green chemistry, agrochemicals, analytical chemistry, toiletries, foods, and cosmetics. This review summarizes several aspects related to the physico-chemical properties of CDs and discusses their potential applications illustrated by recent examples. The prospects for their use in several areas are also described.

The discussion based on surfactant cleaning action is commonly used in chemistry classrooms for the comprehension of theoretical concepts related to surface tension and micelle formation. The experimental quantification of surface tension of aqueous solutions of surfactants provides the practical instruments for this discussion. The present paper describes a simplification on the common apparatus employed for the drop-weight method, making the determination of surface tension accessible to any chemistry lab. The surface tension of various liquids and the critical micelle concentration, CMC, of three commercial surfactants were measured with this modified method, and proved to be consistent with literature values.