The current concept in searching for new bioactive products, including mainly original active substances with potential application in pharmacy and medicine, is based on compounds with a previously determined structure, well-known properties, and biological activity profile. Nowadays, many commonly used drugs originated from natural sources. Moreover, some natural materials have become the source of leading structures for processing further chemical modifications. Many organic compounds with great therapeutic significance have the nitro group in their structure. Very often, nitro compounds are active substances in many well-known preparations belonging to different groups of medicines that are classified according to their pharmacological potencies. Moreover, the nitro group is part of the chemical structure of veterinary drugs. In this review, we describe many bioactive substances with the nitro group, divided into ten categories, including substances with exciting activity and that are currently undergoing clinical trials.

The kumquat tree occurs in practically all countries of the subtropical zone. Kumquat fruits with a characteristic shape, size, colour and taste are the smallest of edible citrus and the only ones that can be eaten as a whole with the peel. Those fruits are rich in fiber, carotenoids, vitamins and minerals. The most important components are polyphenols showing antioxidant properties, in particular flavonoids of which the one characteristic is phloretin. The essential oils extracted from them are rich in numerous terpenoids, responsible for fragrance and aroma. An extensive literature review was carried out to collect data on the chemical composition of kumquat fruit and other selected parts of the plant. These data, depending on the variety, origin, part of the plant and method of obtaining were compiled and presented in the appropriate tables and figures. The structures of the most important components were also presented. Due to their nutritional properties and biological activity (antioxidant, antimicrobial, antitumor etc.) these components are potential sources of ingredients for foods, phytopharmaceuticals and cosmetics.

Nitroimidazoles have wide range of therapeutic uses mainly as anaerobic antibacterials and antiprotozoal agents. Some bicyclic nitroimidazodihydrooxazoles and nitroimidazotetrahydrooxazines are found to be antituberculosis agents. Hence, the biological and chemical properties of mentioned substances are of great interest to scientists. The aim of this review is to show the general knowledge concerning the chemistry and biological activity of some nitroimidazole derivatives, based on experimental studies. The results of biological tests provide many useful information on the effects of particular groups or other structural elements on the level of pharmacological activity. Also, these studies can be helpful in further planning of syntheses of active substances with using nitroimidazole moiety.

Many interesting applications have been found for nitroimidazoles as therapeutic agents. Among others, some of these compounds can radiosensitize hypoxic tumor cells. The introduction of a second nitroimidazole ring to the molecule can improve the level of its pharmacological effect. The aim of this article is to overview the literature concerning active compounds that contain two nitroimidazole moieties in their structures.

Nowadays, dynamic development in nanotechnological sciences is observed. Nanoparticles are frequently used in medicine and pharmacy as delivery systems for different kinds of active substances. One of the latest developed substances, with an unusually wide scope of utility, is graphene. The ways of its use in different fields of industry, not only pharmaceutical and medical, have been a subject of study for many research groups since the moment of its development in 2004. Graphene in pure form is highly hydrophobic. However, the presence of defects on its surface allows chemical modifications to be made, e.g. introduction of oxygen groups by covalent bonding. Also, non-covalent modifications are extensively used, including van der Waals forces, hydrogen bonding, coordination bonds, electrostatic and π-π stacking interactions. Due to the large surface area, graphene can be used in combination therapy, consisting in simultaneous administration of two or more pharmacologically active agents. Another interesting approach is gene therapy. Application of the PEI-graphene oxide system increased the efficacy of transfection. Possibilities of graphene and graphene oxide are not limited to their use as active substance delivery systems. These compounds by themselves were also found to be bacteriostatic and antibacterial agents.