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A novel oil-in-water (O/W) microemulsion (ME) loading with Ferulic acid (FA) was created, featuring transparent, thermodynamically stable, and forms spontaneously. The formula of FA-loaded microemulsion was optimized based on pseudo-ternary phase diagram, Box Behnken design (BBD) and dissolution test. The optimized formula (2 %FAME) consisted of 1-Decanol (3.98 %, w/w), Cremophor®RH40 (6.72 %, w/w), Tween 80 (0.75 %, w/w), 1,3-Butanediol (29.85 %, w/w), water (56.71, w/w) and FA (2 %, w/w). The microscopic morphology and droplet size distribution were investigated by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The unique emulsion enhanced the solubility of FA in water while demonstrating good stability, controlled release properties, significant free radical scavenging ability and ultraviolet-B (UVB) absorption capacity. Sunscreen properties were demonstrated by Carbomer®934 gel. The sunscreen gel exhibited sun protection properties, while the FA microemulsion demonstrated synergistic effect with ZnO, resulting in a significant enhancement of SPF. These results demonstrate that this novel microemulsion system not only improves the bioavailability of FA, but also provides valuable insights into the development and application of natural UV filters. [Display omitted] • The microemulsion was prepared using a new system of long and short chain alcohols. • The formula was optimized by RSM and phase diagram. • The load, stability, ABTS·+, in vitro release and sunscreen gel of microemulsion were studied. [ABSTRACT FROM AUTHOR]

To cope with the biotic and abiotic stresses experienced within their environment, marine macroalgae have developed certain defence mechanisms including the synthesis of photo-protective molecules against light and particularly harmful UV radiation. The aim of this study was to screen selected red algae, a highly diverse phylogenetic group, for the production of photo-protective molecules. The pigment content and composition (i.e. chlorophyll- a , phycobiliproteins and carotenoids) and the composition of mycosporine-like amino acids (MAAs) were studied in 40 species of red macroalgae collected in Brittany (France), at two distinct periods (i.e. February and July 2017). A high inter-specific variability was demonstrated in terms of pigment content and MAA composition. Twenty-three potential MAAs were detected by HPLC, and six were identified by LC-MS (i.e. shinorine, palythine, asterina-330, porphyra-334, usurijene and palythene). This is the first study to report on the composition of pigments and MAAs in a diverse group of red seaweeds from Brittany, including some species for which the MAA composition has never been studied before. Nevertheless, the results suggested that some species of red algae are more likely to cope with high levels of light radiation since those species such as Bostrychia scorpioides, Porphyra dioica , Gracilaria vermiculophylla and Vertebrata lanosa are living in environments exposed to higher levels of irradiation, and had various MAAs in addition to their photo-protective pigments. Image 1 • Detection of 23 potential MAAs in 40 red macroalgae, including 6 already identified. • First report on the MAAs composition for some red seaweeds. • High variability in MAAs composition between the different species, with no link with phylogeny or morphology. • A MAAs extraction method using 70% ethanol being less toxic than conventional methanol. [ABSTRACT FROM AUTHOR]

The formation, characterization, photo-protective properties and release profiles of folic acid-loaded nanolaminated films were investigated by UV–visible spectroscopy, FTIR, Raman and SEM microscopy. Food-grade alginate/chitosan nanolaminates were obtained by the layer-by-layer technique and folic acid (FA) was incorporated by post-diffusion. The FA concentration of loading solutions and immersion time significantly affected the FA content in nanolaminates. The maximum FA loading was reached using FA solutions at 10 mg/mL for 30 min (54.4 μg/cm 2 ), or 12.5 mg/mL for 120 min (≈70 μg/cm 2 ). Nanolaminates containing FA were more stable under ultraviolet light exposure than non-encapsulated FA. The rate and concentration of FA released from nanolaminates were greater at buffer pH 7 than at pH 3, which might play a key role in the delivery and bioavailability of nutraceuticals. These results provide important information for the design of nanolaminates containing hydrophilic active compounds for food applications. [ABSTRACT FROM AUTHOR]

The formation, characterization, photo-protective properties and release profiles of folic acid-loaded nanolaminated films were investigated by UV–visible spectroscopy, FTIR, Raman and SEM microscopy. Food-grade alginate/chitosan nanolaminates were obtained by the layer-by-layer technique and folic acid (FA) was incorporated by post-diffusion. The FA concentration of loading solutions and immersion time significantly affected the FA content in nanolaminates. The maximum FA loading was reached using FA solutions at 10 mg/mL for 30 min (54.4 μg/cm 2 ), or 12.5 mg/mL for 120 min (≈70 μg/cm 2 ). Nanolaminates containing FA were more stable under ultraviolet light exposure than non-encapsulated FA. The rate and concentration of FA released from nanolaminates were greater at buffer pH 7 than at pH 3, which might play a key role in the delivery and bioavailability of nutraceuticals. These results provide important information for the design of nanolaminates containing hydrophilic active compounds for food applications. [ABSTRACT FROM AUTHOR]

To more thoroughly characterize the mechanism regulating the conversion of red maple tree ( Acer rubrum L. ‘Brandywine’) foliar coloration in autumn, we analyzed the leaf coloration process using the Lab color space scale, and compared the anthocyanin concentrations, photosynthetic pigment contents, soluble sugar contents, and the phenylalanine ammonia lyase and polyphenol oxidase activities between control and band-treated red maple seedlings. We observed that stem banding enhanced the development of leaves exhibiting brilliant red coloration in the upper treated branches, and weakened the brightness of yellow leaves. Additionally, studies also revealed that leaf anthocyanin contents increased significantly. Moreover, carotenoid contents and polyphenol oxidase activity decreased considerably by banding. In contrast, the chlorophyll pigment, phenylalanine ammonia lyase activity and soluble sugar contents were only minimally affected by the long-term banding of trees. Our results indicate that the Lab color model is appropriate for quantifying leaf coloration changes, and for revealing the relationship between leaf coloration and internal physiological changes. Changes to leaf coloration are a consequence of the actions of photosynthetic pigments and anthocyanins. Our results also demonstrate that anthocyanin accumulation influences the underlying biochemical mechanism. The successful manipulation of leaf coloration changes highlights the significance of anthocyanins in this process, and is consistent with the possibility that anthocyanin accumulation influences the underlying biochemical activities. [ABSTRACT FROM AUTHOR]

Due to its characteristic of high biomass yield potential, there is considerable interest in cultivating Phalaris arundinacea L. cv. ‘chuancaoyin No.3' (reed canary grass) on the Qinghai-Tibet Plateau where there is an abundance of alpine steppe meadow and a potential large market for animal husbandry. In this study, we 1) investigate whether reed canary grass exhibits superior productive capacity to Elymus nutans ‘Aba' ( E. nutans ), ordinary common pasture, during the long warm days of summer at high-altitude; and 2) compare the cold tolerance between reed canary grass and E. nutans , including photosynthesis, photo-inhibition, and photo-protection. The results suggest that reed canary grass exhibits higher photosynthetic capacity compared to E. nutans at latitudes of the cool temperate zone. Meanwhile, cold-induced photo-inhibition and photo-damage at high altitudes in reed canary grass were due to both stomatal and non-stomatal limitation, and the enhancement in photo-respiration, thermal dissipation, and Mehler reaction are important processes to minimize the negative effects of high elevation and a cold environment. [ABSTRACT FROM AUTHOR]

The ability of Rhodopseudomonas palustris cells to rapidly acclimate to high light irradiance is an essential issue when cells are grown under sunlight. The aim of this study was to investigate the photo-acclimation process in Rhodopseudomonas palustris 42OL under different culturing conditions: (i) anaerobic (AnG), (ii) aerobic (AG), and (iii) under H 2 -producing (HP) conditions both at low (LL) and high light (HL) irradiances. The results obtained clearly showed that the photosynthetic unit was significantly affected by the light irradiance at which Rp. palustris 42OL was grown. The synthesis of carotenoids was affected by both illumination and culturing conditions. At LL, lycopene was the main carotenoid synthetized under all conditions tested, while at HL under HP conditions, it resulted the predominant carotenoid. Oppositely, under AnG and AG at HL, rhodovibrin was the major carotenoid detected. The increase in light intensity produced a deeper variation in light-harvesting complexes (LHC) ratio. These findings are important for understanding the ecological distribution of PNSB in natural environments, mostly characterized by high light intensities, and for its growth outdoors. [ABSTRACT FROM AUTHOR]

Cyclic electron flow (CEF) alleviates PSII photo-inhibition under high light by at least two different mechanisms: one is liked to thermal energy dissipation (qE) and the other one is independent of qE. However, the latter mechanism is unclear. Because the photodamage to PSII primarily occurred at the oxygen-evolving complex (OEC), and the stability of OEC is dependent on proton gradient across thylakoid membrane (ΔpH), we hypothesize that the CEF-dependent generation of ΔpH can alleviate photodamage to OEC. To test this hypothesis, we determined the effects of antimycin A (AA), methyl viologen (MV), chloramphenicol (CM), nigericin (Nig) on PSII activity and the stability of OEC for leaves of a light-demanding tropical tree species Erythrophleum guineense by the analysis of OKJIP chlorophyll a fluorescence transient. After high light treatment, the stronger decrease in F v / F m in the AA-, CM-, MV-, and Nig-treated samples was accompanied with larger photo damage of OEC. The AA-treated samples significantly showed lower CEF activity than the H 2 O-treated samples. Although the AA-treated leaves significantly showed stronger PSII photo-inhibition and photo-damage of OEC compared to the H 2 O-treated leaves, the value of non-photochemical quenching did not differ between them. Therefore, CEF activity was partly inhibited in the AA-treated samples, and the stronger PSII photo-inhibition in the AA-treated leaves was independent of qE. Taking together, we propose a hypothesis that CEF-dependent generation of ΔpH under high light plays an important role in photoprotection for the OEC activity. [ABSTRACT FROM AUTHOR]

We have prepared a chitosan polymer modified with gallic acid in order to develop an efficient protection strategy biological membranes against photodamage. Lipid bilayers were challenged with photoinduced damage by photosensitization with methylene blue, which usually causes formation of hydroperoxides, increasing area per lipid, and afterwards allowing leakage of internal materials. The damage was delayed by a solution of gallic acid in a concentration dependent manner, but further suppressed by the polymer at very low concentrations. The membrane of giant unilamellar vesicles was covered with this modified macromolecule leading to a powerful shield against singlet oxygen and thus effectively protecting the lipid membrane from oxidative stress. The results have proven the discovery of a promising strategy for photo protection of biological membranes. [ABSTRACT FROM AUTHOR]

Mistletoe plants that are positioned on the canopy of their hosts are more susceptible to UV radiation exposure. These aerial plants are resistant to damage by UV radiation due the presence of epidermal constituents such as the cuticle, cork layer, trichomes and antioxidant secondary metabolites. In response to the photo-oxidative stress associated with UV exposure, plants generally deploy photo-protective responsive mechanisms that involve the biosynthesis of UV absorbing phenolic compounds such as chlorogenic acids (CGAs). The hydroxycinnamic acid moieties of these CGAs are predominantly in the trans configuration, naturally. However, excessive sunlight exposure of plants containing these compounds can result in geometrical isomerisation, characterized by the formation of cis isomers. Therefore, in this study, the effect of UV light radiation on the CGA composition of Viscum combreticola Engl. (Santalacaeae) plants using an in vitro model was unravelled through UHPLC-q-TOF-MS-based metabolic profiling. Interestingly, the findings of this study revealed that this plant has a diverse chemical composition of CGAs that is characterized by epimerization, monoacylation, homodiacylation and heterodiacylation of the quinic acid (QA), thereby, contributing to the state of readiness in these plants against sunlight or UV exposure. In addition to the commonly reported cinnamoyl containing heterodiacylated CGAs, hydroxybenzoyl containing heterodiacylated CGAs were also reported in this study. Moreover, cis isomers (24 in total) of some CGAs were identified in the non-irradiated samples and the formation of these compounds has been reported to help plants in the mitigation of photo-oxidative stress. An additional 28 cis isomers of CGAs and HCA derivatives were observed in the UV-irradiated samples, hence, further increasing the complexity of the metabolome of this plant, with a total of 108 compounds identified in this study. The presence of epimers, positional and geometrical isomers of these compounds could be a biochemical strategy to maximize the chemical arsenal of this plant to withstand the photo-oxidative stress posed by UV radiation from the sunlight. Due to purported pharmacological properties associated with the identified compounds these parasitic plants can be a rich source of prospective therapeutic compounds that can be employed as drug discovery leads. Moreover, UV radiation might be essential in future to produce potent drugs since plants naturally produce these compounds in low quantities. • The semi-parasitic plant, Viscum combreticola Engl. contains structurally diverse cinnamic acid derivatives. • The cinnamic acid derivatives of Viscum combreticola Engl. undergo trans/cis isomerization upon UV exposure. • The presence of chlorogenic acids protect Viscum combreticola Engl. against excessive sunlight or UV light exposure. • The use of the LC-MS and molecular networking approach helps in identification of UV-responsive metabolites in plants. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of using photosynthetic bacteria (PSB) to produce biomass and carotenoid while treating wastewater. The effects of light intensity on the biomass, carotenoid and bacteriochlorophyll accumulation in together with pollutant removal were studied. Results showed that it was feasible to use PSB to treat wastewater as well as to produce biomass or carotenoid. 2000 lux was an optimal intensity for biomass production and COD removal, and the corresponding values were 2645 mg/L and 94.7%. 8000 lux was an optimal light intensity for carotenoid production (1.455 mg/L). Mechanism analysis displayed that the greater the bacteriochlorophyll and carotenoid were secreted, the lower the light conversion efficiency turned out to be. The highest light conversion efficiency was achieved at 500 lux; the ATP production, biomass production, and COD removal were the highest at 2000 lux, but the bacteriochlorophyll and carotenoid content were the lowest at 2000 lux. [ABSTRACT FROM AUTHOR]

Adaptations to freezing air temperature in temperate understory species of Rhododendron include physiological processes, anatomical changes, and thermonastic leaf movements. Leaves roll transversely and leaf-lamina angle decreases in relation to horizontal as temperatures decrease below a critical freezing temperature. Within the genus Rhododendron, tolerance of cold conditions is greater in species with thermonastic leaf movements than species without. The leaf movements protect critical physiological processes such as photosynthesis from damage due to the synergistic effects of cold temperatures, and high light common to winter conditions in temperate forests. In particular, the absence of these leaf movements increases photoinhibition, and species that lack these adaptations exhibit distinctly different physiological and anatomical mechanisms of photo-protection during cold conditions. The biomechanical or physiological causes for thermonastic leaf movements have been difficult to resolve because of the lack of distinctive anatomical and morphological features associated with these leaf movements. Nevertheless, it is firmly established that the lower the petiole turgor potential the lower the leaf-lamina angle in relation to horizontal. However, the cause of leaf rolling is unclear. In this study, experiments on sectioned leaves implicate both longitudinal and lateral thermonastic rolling forces, likely driven by water redistribution between apoplast and symplast, and regulated by aquaporins. This should result in abaxial-adaxial differential turgor pressures that vary markedly along the mediolateral direction. We postulate that the combined effect of the leaf morphology, anisotropy in rolling forces and the geometrical constraints due to the relatively stiff midrib causes leaf rolling, consistent with the mechanics of a thin plate with anisotropic spontaneous curvature. We expect a correlation between the rolling forces and veination microstructure that remains to be explored for a complete understanding of leaf adaptations to freezing in understory evergreen Rhododendron species, as well as more general thermonastic responses. [ABSTRACT FROM AUTHOR]

Abstract: Some solar-powered sea slugs are capable of incorporating chloroplasts directly in their cell cytosol sustaining photosynthesis for significant time periods. This phenomenon is known as kleptoplasty. Kleptoplastids show high functionality levels but little is known about their photo-regulatory mechanisms. The main objective was to investigate the functionality of the xanthophyll cycle using the sacoglossan Elysia timida that acquires kleptoplasts from Acetabularia acetabulum. Xanthophyll cycle functionality was tested using a combination of PAM fluorescence and HPLC pigment analysis. Rapid light curves (RLC) and steady state light curves were carried out in both organisms. E. timida RLC showed a rETR inflexion point after 700μmolE−1 m−2 s−1 that was not visible on A. acetabulum. This was attributed to the fact that the animal closed the parapodia in high light intensities, thus shading the kleptoplasts leading to higher PSII quantum efficiencies. This behaviour also resulted in Ek values being significantly higher in E. timida (ANOVA, F(1, 27) =7.49, p<0.05). The xanthophyll cycle was shown to be functional with kleptoplasts xanthophyll ratio, i.e. zea/(vio+ant+zea) increasing with exposure to higher light intensities (F(1, 23) =122.83, p<0.01) and showing a strong linear relationship with non-photochemical quenching measurements. The present study showed that E. timida was capable of combining a behavioural photo-regulation mechanism (opening/closing the parapodia) with a functional physiological photo-regulation mechanism (xanthophyll cycle) increasing their photo-regulation capacity, keeping their maximum photosynthetic capacity for longer periods than their food source. [ABSTRACT FROM AUTHOR]

Abstract: Low-temperature crystalline deposition techniques are important, especially for coating polymer films that cannot tolerate high temperatures. In this work, crystalline anatase titanium dioxide (TiO2) thin films were deposited by reactive radio-frequency (RF) magnetron sputtering on unheated poly(ethylene terephthalate) (PET) films. The stability of the polymer film under UV-light irradiation in air was then studied. With only a TiO2 layer the polymer film was degraded by in-air, UV radiation. However, a transparent bilayer coating, consisting of a TiO2 layer on top of an ultra-thin sputtered alumina (Al2O3) layer, on the PET film effectively protected the polymer layer from photo-oxidation. Furthermore, the top anatase TiO2 layer has very good photo-catalytic activity, as shown by its ability to photo-degrade rhodamine B dye solution. The combination of these two properties allows photo-stable and transparent polymer/ceramic layered media with a self-cleaning surface. [Copyright &y& Elsevier]