Search

A powerful toolbox is needed to turn the linear plastic economy into circular. Development of materials designed for mechanical recycling, chemical recycling, and/or biodegradation in targeted end-of-life environment are all necessary puzzle pieces in this process. Polyesters, with reversible ester bonds, are already forerunners in plastic circularity: poly-(ethylene terephthalate) (PET) is the most recycled plastic material suitable for mechanical and chemical recycling, while common aliphatic polyesters are biodegradable under favorable conditions, such as industrial compost. However, this circular design needs to be further tailored for different end-of-life options to enable chemical recycling under greener conditions and/or rapid enough biodegradation even under less favorable environmental conditions. Here, we discuss molecular design of the polyester chain targeting enhancement of circularity by incorporation of more easily hydrolyzable ester bonds, additional dynamic bonds, or degradation catalyzing functional groups as part of the polyester chain. The utilization of polyester circularity to design replacement materials for current volume plastics is also reviewed as well as embedment of green catalysts, such as enzymes in biodegradable polyester matrices to facilitate the degradation process. [ABSTRACT FROM AUTHOR]

Uncontrolled oxidative stress production, especially in the outer retina is one of the causes of retinal degenerations. Mitochondria are considered the principal source of oxidative stress. However, a Reactive Oxygen Intermediates (ROI) production in the retinal photoreceptor layer seems to depend also on the expression of an extramitochondrial oxidative phosphorylation (OxPhos) machinery in the rod outer segments (OS). In fact, OS conduct aerobic metabolism, producing ATP through oxygen consumption, although it is devoid of mitochondria. As diterpenes display an antioxidant effect, we have evaluated the effect Manool, extracted from Salvia tingitana, on the extramitochondrial OxPhos and the ROI production in the retinal rod OS. Results confirm that the OxPhos machinery is ectopically expressed in the OS and that F1Fo‐ATP synthase is a target of Manool, which inhibited the OS ATP synthesis, binding the F1 moiety with high affinity, as analysed by molecular docking. Moreover, the overall slowdown of OxPhos metabolism reduced the ROI production elicited in the OS by light exposure, in vitro. In conclusion, data are consistent with the antioxidant properties of Salvia spp., suggesting its ability to lower oxidative stress production, a primary risk factor for degenerative retinal diseases. Significance of the study: Here we show that Manool, a diterpene extracted from Salvia tingitana has the potential to lower the free radical production by light‐exposed rod outer segments in vitro, by specifically targeting the rod OS F1Fo‐ATP synthase belonging to the extramitochondrial OxPhos expressed on the disk membrane. The chosen experimental model allowed to show that the rod OS is a primary producer of oxidative stress linked to the pathogenesis of degenerative retinal diseases. Data are also consistent with the antioxidant and anti‐inflammatory action of Salvia spp., suggesting a beneficial effect also in vivo. [ABSTRACT FROM AUTHOR]

The terpene‐based monomers and polymers reported in the literature are mostly hydrophobic and this is limiting their use in aqueous environments. To address this drawback, we have developed a novel synthetic strategy to functionalise a model terpene monomer in order to improve hydrophilicity and the number of polar groups on the polymer side chains. To produce a highly hydrophilic monomer, carvone (meth)acrylate was chosen as the primary feedstock. Carvone has more functionalisable double bonds than other commercial cyclic terpenes and offers the potential for the maximum number of hydrophilic groups per monomer molecule. The monomers were homopolymerised and copolymerised to generate novel green hydrophilic and amphiphilic terpene‐based polymers which were characterised by 1H–13C NMR, gel permeation chromatography, TGA and DSC analyses. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]