Synthesis and quantification of oligoesters migrating from starch-based food packaging materials.

The term oligomer refers to structurally diverse compounds coming from incomplete polymerisation or polymer degradation. Their ability to migrate into foodstuffs along with recent studies about their bioavailability and toxicity have risen concerns about the scarcity of standards needed to perform thorough analytical and toxicological studies. In this work, migration extracts of three starch-based biopolymers films for the packaging of fruits and vegetables were analysed according to European legislation 10/2011. Oligoesters analysed by UPLC-MS(QTOF) were the main non-intentionally added substances (NIAS) identified in the food simulants. A stepwise synthesis approach was used to synthesise and isolate eleven cyclic and linear oligoester standards ranging from 2 to 8 monomers based on adipic acid, 1,4-butanediol, isophtalic acid and propylene glycol monomers. These standards were characterised by 1H and 13C NMR as well as high resolution mass spectrometry. An overall high purity of > 98 % was achieved as detected by UPLC-MS(Orbitrap). The standards were then used to unequivocally identify the oligoesters in the migration assay samples by comparing their UPLC-MS/MS spectra, and to semi-quantify or fully quantify these migrant oligoesters. The oligoester quantification results deemed safe only one out of the three biopolymer films according to their threshold of toxicological concern concept. The work herein described aims to contribute towards the oligomers knowledge gaps, opening the door for comprehensive toxicological risk and absorption, distribution, metabolism, excretion and toxicity (ADMET) studies.

A new synthetic route towards multifunctionalized cyclic amidrazones for feeding chemical space.

In the context of growing impetus to develop new molecular scaffolds as well as a variety of 3D fragments to escape from flatland, we have reintroduced the accessibility of the underexplored azaheterocyclic amidrazones as promising bioisosteres. Herein, we present an original and versatile approach to synthesize cyclic amidrazones functionalized at different positions of the scaffold in view of diversifying the substitution pattern towards multifunctionalization, extension or fusion of the ring system and 3D-shaping of fragments. This unprecedented synthetic route represents a sweet achievement to cover further lead-like chemical space.