Sustainable and Scalable Enzymatic Production, Structural Elucidation, And Biological Evaluation of Novel Phlorizin Analogues.

It is not unusual for naturally occurring compounds to be limited for their use in cosmetics due to their low water solubility. Recently, aiming at accessing novel phlorizin (a glycosylated bioactive recovered from apple tree wood and already used in cosmetics as antioxidant ingredient) analogues, we reported the synthesis of very promising - but low water-soluble - biomass-derived chalcones (CHs) and dihydrochalcones (DHCs) exhibiting antioxidant and anti-tyrosinase activities. Glycosylating bioactive compounds being one of the most common strategies to increase their water solubility, herein we report the enzymatic glycosylation of the CHs mentioned above, as well as DHC using cyclodextrin glycosyltransferases (CGTase), enzymes well-known for catalyzing the selective α(1→4) transglycosylation.

Phenolic Compounds Extracted from Cherry Tree ( Branches: Impact of the Process on Cosmetic Properties.

Cherry tree branches ( var Rosaceae) are agricultural by-products that are often neglected, yet they are rich in phenolic compounds and highly appreciated for their numerous biological activities. Extracts of cherry tree branches were evaluated for their use in cosmetics, particularly for their antioxidant, anti-tyrosinase, and antimicrobial activities. Samples were obtained by accelerated solvent extraction (ASE) at different ethanol percentages and different temperatures.

Towards developing novel and sustainable molecular light-to-heat converters.

Light-to-heat conversion materials generate great interest due to their widespread applications, notable exemplars being solar energy harvesting and photoprotection. Another more recently identified potential application for such materials is in molecular heaters for agriculture, whose function is to protect crops from extreme cold weather and extend both the growing season and the geographic areas capable of supporting growth, all of which could help reduce food security challenges. To address this demand, a new series of phenolic-based barbituric absorbers of ultraviolet (UV) radiation has been designed and synthesised in a sustainable manner.

Synthesis of Biobased Phloretin Analogues: An Access to Antioxidant and Anti-Tyrosinase Compounds for Cosmetic Applications.

The current cosmetic and nutraceutical markets are characterized by a strong consumer demand for a return to natural products that are less harmful to both the consumers and the environment than current petrosourced products. Phloretin, a natural dihydrochalcone (DHC) found in apple, has been widely studied for many years and identified as a strong antioxidant and anti-tyrosinase ingredient for cosmetic formulations. Its low concentration in apples does not allow it to be obtained by direct extraction from biomass in large quantities to meet market volumes and prices.

New Generation UV-A Filters: Understanding Their Photodynamics on a Human Skin Mimic.

The sparsity of efficient commercial ultraviolet-A (UV-A) filters is a major challenge toward developing effective broadband sunscreens with minimal human- and eco-toxicity. To combat this, we have designed a new class of Meldrum-based phenolic UV-A filters. We explore the ultrafast photodynamics of coumaryl Meldrum, CMe, and sinapyl Meldrum (SMe), both in an industry-standard emollient and on a synthetic skin mimic, using femtosecond transient electronic and vibrational absorption spectroscopies and computational simulations.

Sinapic Acid Esters: Octinoxate Substitutes Combining Suitable UV Protection and Antioxidant Activity.

In 2021, Hawaii will permanently ban the use and sale of octinoxate-based sunscreens as studies have shown serious impacts of such UV filters on the coral reef. This ban, which could be generalized to other countries, highlights the extreme need to offer alternative UV filters that are not only effective in terms of sun protection, but also healthy with regards to human health and the environment. In this context, a wide library of -hydroxycinnamic esters deriving from naturally occurring sinapic acid has been synthesized using a Knoevenagel-Doebner condensation.

Innovative Bio-Based Organic UV-A and Blue Light Filters from Meldrum's Acid.

Faced with the ban of some organic UV filters such as octinoxate or avobenzone, especially in Hawaii, it became essential to offer new alternatives that are both renewable and safe for humans and the environment. In this context, a class of bio-based molecules displaying interesting UV filter properties and great (photo)stability has been developed from Meldrum's acid and bio-based and synthetic -hydroxycinnamic acids, furans and pyrroles. Moreover, -hydroxycinnamic acid-based Meldrum's derivatives possess valuable secondary activities sought by the cosmetic industry such as antioxidant and anti-tyrosinase properties.

Sustainable Synthesis of -Hydroxycinnamic Diacids through Proline-Mediated Knoevenagel Condensation in Ethanol: An Access to Potent Phenolic UV Filters and Radical Scavengers.

-Hydroxycinnamic diacids are reaction intermediates of the classical Knoevenagel-Doebner condensation between malonic acid and benzaldehydes. As they are generally obtained in low yields, they remain relatively under-studied and under-exploited. Herein, we developed and optimized a sustainable synthetic procedure allowing the production of these compounds in good to high yields (60-80%) using proline as the catalyst and ethanol as the solvent.