A series of twenty segmented poly(ester-urethane)s (PEUs) were synthesized, by the reaction of four different macrodiols derived from ε-caprolactone (CL) and 1,8-octanediol (Oct), 1,6-hexamethylene diisocyanate (HDI), and three different carotenoids, (3R,3′R,6′R)-lutein (1) obtained from a renewable source such as marigold (Tagetes erecta L.), (3R,3′S)-zeaxanthin (2) and (3R,3′S)-astaxanthin (3) obtained by partial synthesis from 1, as chain-extender agents. The mechanical properties of the PEUs showed evident plastic behavior. Some PEUs samples exhibited double segregation phases attributed to PCL (soft segment) and 1, 2, and 3/HDI (hard segment) detected by DSC. This work represents the first report of the use of carotenoids as chain extenders in the synthesis of PEUs.

The present study focuses on an introductory analysis of the use of three xanthophylls as additives for green lubricant applications. For this purpose, the additives were characterized by FTIR and ¹H-NMR techniques, and the bio-lubricants were described by their physical properties. The effect of the natural compounds on the friction and wear properties of bio-lubricants were evaluated by sliding friction tests under boundary conditions, as confirmed by an analysis of the lubricating film thickness. The antioxidant capacity was analyzed by FTIR spectroscopy. It was observed better wear protection in castor oil with xanthophylls than without these additives. The wear rate was reduced up to 50% compared with neat oil. Lesser beneficial effects were appreciated in friction coefficient since it was increased 25%. The best contribution was observed with astaxanthin as an additive. In addition, a significant improvement in the oxidation of castor oil, complemented with this additive, was exhibited by FTIR analysis. It was found that xanthophylls could be employed as additives for totally biodegradable lubricant applications since they have better tribological and antioxidant behavior than current additives.

The unexpected reactivity of fluorinated oxazolones with alkynyl Fischer carbenes is reported. The loss of the –CF ₃ and a cascade process involving nucleophilic additions were observed.

Three xanthophylls [(3R,3′R,6′R)-lutein (1), (3R,3′S)-zeaxanthin (2), and (3R,3′S)-astaxanthin (3)] were used for the first time as initiators in the ring-opening polymerization (ROP) of ε-caprolactone (CL) catalyzed by tin(II) 2-ethylhexanoate [Sn(Oct)₂] for the synthesis of novel sustainable xanthophyll-containing poly(ε-caprolactone)s (xanthophylls-PCL). The obtained polyesters were characterized by ¹H and ¹³C NMR, FT-IR, DSC, SEC, and MALDI-TOF MS, and their use as additives in green lubricants was evaluated using a sliding friction test under boundary conditions. Xanthophylls-PCL were obtained with good conversions and with molecular weights determined by SEC to be between 2500 and 10 500 Da. The thermal properties of xanthophyll-polyesters showed a crystalline domain, detected by DSC. Lastly, the green lubricant activity of these polymers was evaluated and the results showed that xanthophylls-PCL could be employed as additives for biodegradable lubricant applications since they have better tribological behavior than current additives, which demonstrates their potential as future commercial materials with interesting eco-friendly properties for diverse applications.

Strength and biocompatibility of composite materials (using a polymer matrix) are used in medicine for various devices such as prostheses and marker clips (biomarkers). Marker clips indicate the site of a lesion in the body, specifically for breast cancer diagnosis or treatment. In general, marker clips are made of steel or titanium, but lately, materials containing biodegradable polymers had been proposed. Our hypothesis is that a copolymer of polylactic acid and poly(ε-caprolactone) (PLA-PCL) could be used as marker clip material. After evaluating different polymer rates performance, metallic nanoparticles (NPs) were included to enhance the stability of the best copolymer and a marker clip prototype was proposed. Characterization of nanoparticles was made by dynamic light scattering (DLS), X-ray diffraction (XRD) and magnetic measurements. Mechanical, thermal and radiopacity properties were evaluated for composites formulation. In vitro, radiopaque experiments showed that BM-2 composite had the best performance. In vivo experiments showed that, after five months, the marker clip prototype maintained its shape, visibility and contrast properties. In consequence, a novel formulation of composite (PLA-PCL/metallic nanoparticles) is suitable for further studies as an alternative material for marker clips for breast cancer lesions.

Carotenoids are natural compounds that have important roles in promoting and maintaining human health. Synthetic astaxanthin is a highly requested product by the aquaculture industry, but natural astaxanthin is not. Various strategies have been developed to synthesize this carotenoid. Nonetheless, these approaches have not only provided limited global yields, but its main commercial source also carries several health risks for humans. In this contribution, the one-pot base-catalyzed reaction of (3R,3’R,6’R)-lutein (1) esters has resulted in a successful isomerization process to easily obtain up to 95% meso-zeaxanthin (2), which in turn is oxidized to (3R,3’S)-astaxanthin (3) with a global yield of 68%. The same oxidation performed with UV irradiation (365 nm) for 5 min provided the highest global yield (76%). These chemical transformations have also been achieved with a significant reduction of the health risks associated with its potential human consumption. Furthermore, this is the first time only one of the configurational isomers has been obtained semisynthetically. The poorly understood formation mechanisms of these two compounds were also investigated using Density-Functional Theory (DFT) calculations. These theoretical studies revealed that the isomerization involves a base-catalyzed deprotonation at C-6’, followed by C-4’ protonation, while the oxidation occurs via free radical mechanisms.