How to name a complex conjugate and allow easy identifications of the carrier, of the bound specific entity and of the link while respecting the established IUPAC rules as much as possible? This is the problem which this new project intends to solve.
In organic chemistry, the nomenclature allows the unequivocal drawing of the molecule structure. In polymer chemistry, the situation is more complex and one can use either the ‘source-based’ or the ‘structure-based’ systems of nomenclature to name a polymer. Source-based nomenclature leads to rather simple names, but it does not reflect the structure of the polymer it names. Information on the polymerization process is necessary to draw it. In contrast, structure-based nomenclature allows the drawing of the polymer structure directly from the name without requiring knowledge of the chemistry involved in the polymer formation. The strict rules of IUPAC organic nomenclature are adapted to the naming of the constitutional units of a polymer.
Recently, the members of the Subcommittee on Polymer Terminology (SPT) prepared a document for the “Nomenclature of Chemically Modified Polymers” (Pure Appl. Chem. 87(3), pp. 307-319 (2015)). This document revealed the need for a particular nomenclature system to deal with current, common structures of conjugates which combine macromolecular carriers and chemical entities.
The field of polymeric conjugates is rapidly growing. The development of conjugates depends on the collaboration of people from different disciplines and the name of a conjugate can be different depending on who generated it among the various specialists. The applications of conjugates require the permanent or temporary immobilization of complex chemical species chemically bound to a carrier that can be a macromolecule, a micelle, a microparticle, a nanoparticle, or a large solid support. These complex chemical species are easily characterized and identified by functional names. In contrast, recognition and identification can be almost impossible if the strict structure-based naming of the conjugate is used, because both the carrier and the complex species are chemically modified. The binding function alters the names of the bound entity as well as that of the polymeric carrier. Sometime this binding function plays an important role, as in the case of specific chemical entities that are to be released by degradation under predefined physical or chemical conditions. In pharmacology, drugs or other bioactive species like peptides, proteins, polysaccharides, or polynucleotides are temporarily attached to polymeric systems for the purpose of being transported up to a targeted site in the human body and released there to exert their therapeutic action. In some applications, conjugates involve molecules with other specific activities, like dyes or radioactive labels, ligands to target receptors present in cell membranes, solubilizing species, stimuli-sensitive entities to make smart systems, or pesticides and insecticides for treatments in agriculture, etc. Some of the carriers of the bound entities can be so complex that they are named using letters like FGFs and VEGF growth factors, albumin and fibrinogen proteins, DNA, siRNA, etc.
IUPAC recommendations for the structure and source-based nomenclatures of polymers have clear limitations when dealing with complex conjugates. This new project aims to create rules that will allow unambiguous and facile naming of such modern complex conjugates together with easy recognition of the moieties introduced to take advantage of their specific activity.
The project is focused on macromolecules (organic or inorganic) suitable for attachment of (or to) complex chemical entities, including small molecules, macromolecules and biopolymers known and named in relation to their utility. However, the recommendations will be applicable to other kinds of carriers (small organic molecule to make prodrugs, inorganic supports, surface and porous systems, etc.) provided they bear identified chemical functions suitable for attachment.
For further information, contact the Task Group Chair Michel Vert <firstname.lastname@example.org>
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