Spirocyclic derivatives as antioxidants: a review.

In recent years, spiro compounds have attracted significant interest in medicinal chemistry due to their numerous biological activities attributed primarily to their versatility and structural similarity to important pharmacophore centers. Currently, the development of drugs with potential antioxidant activities is of great importance since numerous investigations have shown that oxidative stress is involved in the development and progression of numerous diseases such as cancer, senile cataracts, kidney failure, diabetes, high blood pressure, cirrhosis, and neurodegenerative diseases, among others. This article provides an overview of the synthesis and various antioxidant activities found in naturally occurring and synthetic spiro compounds.

Antimicrobial properties of novel ionic liquids derived from imidazolium cation with phenolic functional groups.

Bacterial infections are nowadays among the major threats to public health worldwide. Thus, there is an urgent and increased need for new antimicrobial agents. As a result, the exploration of the antimicrobial properties of different substances including ionic liquids (ILs) has recently attracted great attention.

Crystal structure of the di-Mannich base 4,4'-di-chloro-3,3',5,5'-tetra-methyl-2,2'-[imidazolidine-1,3-diylbis(methyl-ene)]diphenol.

The title compound, C21H26Cl2N2O2, was prepared in a solvent-free microwave-assisted synthesis, and crystallizes in the ortho-rhom-bic space group Pna21. The imidazolidine ring adopts an envelope conformation and its mean plane is almost perpendicular to the two pendant aromatic rings [dihedral angles = 84.61 (9) and 86.

6,6'-Dimethyl-2,2'-[imidazolidine-1,3-diyl-bis(methyl-ene)]diphenol.

In the title compound, C19H24N2O2, a di-Mannich base derived from 2-methyl-phenol and 1,3,6,8-tetra-aza-tri-cyclo-[4.4.1.

4,4'-Di-tert-butyl-2,2'-[imidazolidine-1,3-diylbis(methyl-ene)]diphenol.

In the title compound, C25H36N2O2, the two tert-butyl-substituted benzene rings are inclined at an angle of 53.5 (3)° to one another. The imidazolidine ring has an envelope conformation with with one of the C atoms of the ethylene fragment as the flap.

4,4'-Dimethyl-2,2'-[imidazolidine-1,3-diylbis(methyl-ene)]diphenol.

The imidazolidine ring in the title compound, C(19)H(24)N(2)O(2), adopts a twist conformation and its mean plane (r.m.s.

4,4'-Difluoro-2,2'-[imidazolidine-1,3-diylbis(methyl-ene)]diphenol.

In the title compound, C(17)H(18)F(2)N(2)O(2), the imidazolidine ring system exists in a twist conformation. The mean plane through this ring system forms dihedral angles of 80.8 (8)° and 66.

2,2'-[Imidazolidine-1,3-diylbis(methyl-ene)]diphenol.

In the title mol-ecule, C(17)H(20)N(2)O(2), the imidazolidine ring adopts a twist conformation. The mean plane through the five atoms of the imidazolidine ring makes dihedral angles of 70.18 (4) and 74.

Repellent activity of essential oils: a review.

Currently, the use of synthetic chemicals to control insects and arthropods raises several concerns related to environment and human health. An alternative is to use natural products that possess good efficacy and are environmentally friendly. Among those chemicals, essential oils from plants belonging to several species have been extensively tested to assess their repellent properties as a valuable natural resource.