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The study of new legumes species in terms of yield and quality of forage under cultivation conditions is essential to improving the productivity of animal production. We evaluated the yield and nutritional quality of forage under irrigation conditions for three wild lupin species from Mexico (L. exaltatus, L. mexicanus, and L. rotundiflorus) at different stages of maturity. The experiment was conducted from November 2016 to March 2017 in Jalisco, Mexico. In general, the dry matter (DM) in all species increased with advancing maturity, but L. exaltatus presented the best production of forage 15,143 kg/ha-1 DM, followed by L. mexicanus (9,140 kg/ha-1 DM) on the third sampling date. The low forage yield in L. rotundiflorus was compensated by a higher average protein content (171.2 g/kg). The highest P and K content was recorded in L. rotundiflorus, whereas Ca and Mg were higher in the forage of L. mexicanus. [ABSTRACT FROM AUTHOR]

The potential of Lupinus exaltatus, L. mexicanus, and L. rotundiflorus foliage as green manure in terms of total dry matter production and nitrogen (N) content was evaluated. This study was conducted from November 2015 to March 2016 in Zapopan Jalisco, México. The experiment was established in a randomized 3×7 block factorial design. Whole plants, leaves and stems were collected at different periods after sowing and analyzed for N and dry matter content. At the start of the experimental period, a slow growth was observed, based on dry matter production; however, at 93 days after sowing, both biomass and total N increased in the aerial part. The lowest and highest N content was found in L. rotundiflorus (1.2 to 4.0%). The highest dry matter and N accumulated in whole plants were found in L. exaltatus at 169 days after sowing with 21,605 and 410.6 kg ha-1, respectively. [ABSTRACT FROM AUTHOR]

The present experiment was carried out to assess the general combining ability (GCA) and specific combining ability (SCA) of six important commercial cultivars of Gossypium hirsutum L. of Venezuela, viz., 'Deltapine 16', 'Tamcot-SP-21', 'Cabuyare', 'Stoneville', 'Ospino' and 'Acala 90-1' and their 15 F1 hybrids, respectively. The data were analyzed using Griffing's Model I Method II. Significant differences were found for all traits evaluated, except for seeds per boll and bolls per plant. Combining ability analysis of variance revealed significant differences for GCA and SCA effects among the parents and hybrids for almost all traits except for seed cotton yield ha-1 and fiber % for GCA and boll set, seed yield, and fiber % for SCA. The results suggested the presence of additive and non-additive gene action for almost all of the traits. The ratio GCA/SCA ranged from 0.59 for fiber fineness to 5.14 for plant height. Cultivars with the best (desired) GCA effects were cv. Cabuyare for blooming initiation, seed yield, and fiber fineness; Stoneville for plant height, stem diameter, number of fruit branches, number of set flowers, and boll weight; Tamcot-SP-21 for boll set and fiber fineness; Deltapine 16 for plant height, 100- seed weight and fiber length; Ospino for fiber strength. Also, the results revealed that Stoneville was the best general combiner for most of the traits. Finally, the correlations among GCA effects of the parents showed negative and significant associations of boll set with plant height and positive and significant associations of fruit branches with plant height, boll weight, and number of set flowers; of set flowers with plant height and boll weight; and of plant height with stem diameter. [ABSTRACT FROM AUTHOR]

Epoxiconazole (EPO) is classified as a persistent organic pollutant due to its ability to persist in the environment for prolonged periods. Its degradation is pivotal in mitigating its environmental impact. This investigation focuses on assessing the degradation of EPO using various methodologies, namely Fenton, photo-Fenton, solar photo-Fenton, and solar photolysis, conducted in both Milli-Q water and groundwater. These experiments encompassed evaluations at both the standard pH typically used in photo-Fenton reactions and the natural pH levels inherent to the respective aqueous environments. Additionally, EPO degradation products were analyzed after a 60-min reaction. Notably, in systems utilizing groundwater, the inclusion of additional iron was unnecessary, as the naturally occurring iron content in the groundwater facilitated the intended processes. Specifically, in Milli-Q water, solar photo-Fenton demonstrated an EPO degradation efficiency of 97%. Furthermore, the substitution of Milli-Q water with groundwater in Fenton-like processes did not significantly affect the efficacy of EPO degradation. These findings underscore the potential of solar photo-Fenton as an economically viable and environmentally sustainable strategy for EPO degradation., (© 2024. The Author(s), under exclusive licence to the European Photochemistry Association, European Society for Photobiology.)

Flavin mononucleotide (FMN) is a dye belonging to the flavin family. These dyes produce photosensitized degradation of organic compounds via reaction with the excited states of the dye or with reactive oxygen species photogenerated from the triplet of the dye. This article presents a new polymeric dye (FMN-CS) composed of the photosensitizer FMN covalently bonded to chitosan polysaccharide (CS). FMN-CS obtained has a molecular weight of 230 × 10 3  g mol -1 and a deacetylation degree of 74.8%. The polymeric dye is an environmentally friendly polymer with spectroscopic and physicochemical properties similar to those of FMN and CS, respectively. Moreover, under sunlight, it is capable of generating 1 O 2 with a quantum yield of 0.31. FMN-CS, like CS, is insoluble in basic media. This allows easy recovery of the polymeric dye once the photosensitized process has been carried out and makes FMN-CS a suitable photosensitizer for the degradation of pollutants in contaminated waters. To evaluate whether FMN-CS may be used for pollutant degradation, the photosensitized degradation of two trihydroxybenzenes by FMN-CS was studied., (© 2023. The Author(s), under exclusive licence to European Photochemistry Association, European Society for Photobiology.)

The effect of Riboflavin-5'-phosphate (RFPO 4 ) sensitization on photocatalytic properties of TiO 2 film was studied. RFPO 4 was adsorbed on film surface to investigate the photophysical properties of TiO 2 upon blue-light photoexcitation. The film was characterized through scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and diffuse reflectance spectroscopy. The efficiency of the TiO 2 /RFPO 4 film was tested for pollutant elimination in aqueous media in a visible-light-driven system. The phenol paradigmatic model was employed in an aqueous solution as a contaminant target. TiO 2 /RFPO 4 sensitized photodegradation of phenol, which produces catechol, hydroquinone, and benzophenone, was monitored by absorption spectroscopy and HPLC. The results indicated that phenol degradation with TiO 2 /RFPO 4 film was due to the photogeneration of two reactive oxygen species, singlet molecular oxygen (O 2 ( 1 Δ g )) and superoxide radical anion (O 2 ·- ) identified through specific detection techniques. The presence of O 2 ( 1 Δ g ) is reported here for the first time as generated from a sensitized TiO 2 film upon visible-light photoirradiation. Based on the photophysical determinations, a photocatalytic mechanism for TiO 2 /RFPO 4 was established., (© 2022. The Author(s), under exclusive licence to European Photochemistry Association, European Society for Photobiology.)

The proherbicide Isoxaflutole (IXF) hydrolyzes spontaneously to diketonitrile (DKN) a phytotoxic compound with herbicidal activity. In this work, the sensitized degradation of IXF using Riboflavin (Rf), a typical environmentally friendly sensitizer, Fenton and photo-Fenton processes has been studied. The results indicate that only the photo-Fenton process produces a significant degradation of the IXF. Photolysis experiments of IXF sensitized by Riboflavin is not a meaningful process, IXF quenches the Rf excited triplet ( 3 Rf*) state with a quenching rate constant of 1.5 · 10 7  m -1  s -1 and no reaction is observed with the species O 2 ( 1 Δ g ) or O 2 · - generated from 3 Rf*. The Fenton reaction produces no changes in the IXF concentration. While the photo-Fenton process of the IXF, under typical conditions, it produces a degradation of 99% and a mineralization to CO 2 and H 2 O of 88%. A rate constant value of 1.0 × 10 9  m -1  s -1 was determined for the reaction between IXF and HO˙. The photo-Fenton process degradation products were identified by UHPLC-MS/MS analysis., (© 2018 The American Society of Photobiology.)

The profusely employed drugs Piroxicam (Piro), Tenoxicam (Teno) and Meloxicam (Melo) belonging to the non-steroidal antiinflammatory drug (NSAID) family of the Oxicams (Oxis) were studied in the frame of two specific conditions: (a) their ROS scavenging ability, in relation to a possible biological antioxidant action and (b) their photodegradability under environmental conditions, in the context of Oxi-contaminated waters. Singlet molecular oxygen (O2((1)Δg)) and superoxide radical anion (O2(-)) were photogenerated through Riboflavin (Rf, vitamin B2)-photosensitization in aqueous and aqueous-methanolic solutions in the presence of Oxi concentrations in the range 50-500 μM. The visible-light absorber vitamin is currently present in all types of natural waters and constitutes the most frequent endogenous photosensitizer in mammals. Hence, it was employed in order to mimic both natural sceneries of interest. All three Oxis quench O2((1)Δg) with rate constants in the order of 10(8)M(-1)s(-1) showing a significant photodegradation efficiency given by a dominant reactive fashion for deactivation of the oxidative species. Although this is not a desirable property in the context of photoprotection upon prolonged photoirradiation, constitutes in fact a promissory aspect for the degradation NSAIDs, in waste waters. Indirect evidence indicates that Melo is also oxidized through a O2(-)-mediated component. The simultaneous presence of Piro plus tryptophan or tyrosine under Rf-photosensitizing conditions, which has taken the amino acids as photooxidizable model residues in a proteinaceous environment, indicates that the NSAID induces a protection of the biomolecules against photodynamic degradation., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objectives: The multifunctional drug niclosamide (NSD), extensively employed therapeutically, is a frequent pollutant of surface waters. Considering the environmental importance of photodegradative processes for this type of contaminant, the kinetic and mechanistic aspects of the possible visible-light-mediated photooxidation of NSD were studied under naturalistic conditions., Methods: The visible-light absorber riboflavin (vitamin B2) was employed as a photosensitizer. The vitamin can usually be found in natural waters and is the most common endogenous photosensitizer in mammals. The interaction of NSD with electronically excited states of Rf and with photogenerated reactive oxygen species (ROS) was evaluated through conventional UV spectroscopy, laser flash photolysis, time-resolved phosphorescence detection of singlet molecular oxygen (O2((1)Δg)), and polarographic dosage of dissolved oxygen., Results: Ground state NSD quenched the long-lived triplet excited state of Rf ((3)Rf*) and the photogenerated ROS (O2((1)Δg)) and superoxide radical anion (O2•−). As a result, NSD was photooxidized. The rate constants for the interaction NSD-O2((1)Δg) are particularly low, in the order of 10(6)/M/s, although the whole interaction is attributable to a pure reactive process. The O2((1)Δg) quenching was faster in alkaline medium, favored by the ionization of the NSD phenolic group. Under Rf-photosensitization, NSD was degraded very much more rapidly than phenol, the latter being considered a paradigmatic water-contaminant model compound. NSD may behave as an antioxidant in bio-environments, as demonstrated employing the photooxidizable amino acid tryptophan as a relevant biological target., Discussion: The results indicate that a O2•−-mediated process is the main route for the Rf-sensitized photooxidation of NSD. Photodegradation of the biocide in the presence and absence of phenol and tryptophan was quantitatively evaluated, discussed, and interpreted in terms of competitive quenching processes of (3)Rf*, O2((1)Δg), and O2•− by the substrates.

The known O2((1)∆g)-sensitizer system Chitosan bounded Rose Bengal (CH-RB), with Rose Bengal (RB) immobilized by irreversible covalent bonding to the polymer Chitosan (CH), soluble in aquous acidic medium, was employed in the photodegradation of three tri-hydroxy benzene water-contaminants (THBs). The system sensitizes the O2((1)∆g)-mediated photodegradation of THBs by a process kinetically favored, as compared to that employing free RB dissolved in the same solvent. Additionally the free xanthene dye, degradable by O2((1)∆g) through self-sensitization upon prolonged light-exposure, is considerably protected when bonded to CH-polymer. The polymeric sensitizer, totally insoluble in neutral medium, can be removed from the solution after the photodegradative cycle by precipitation through a simple pH change. This fact constitutes an interesting aspect in the context of photoremediation of confined polluted waters. In other words, the sensitizing system could be useful for avoiding to dissolve dyestuffs in the polluted waters, in order to act as conventional sunlight-absorbing dye-sensitizers. In parallel the interaction CH-O2((1)∆g) in acidic solution was evaluated. The polymer quenches the oxidative species with a rate constant 2.4 × 10(8) M(-1) s(-1) being the process mostly attributable to a physical interaction. This fact promotes the photoprotection of the bonded dye in the CH-RB polymer., (© 2014 The American Society of Photobiology.)

Kinetic and mechanistic aspects of the photochemical and microbiological degradation of the herbicide Maleic Hydrazide (MH) have been studied. Riboflavin (Rf, vitamin B2) was employed as a main photosensitizer whereas Humic Acid (HA) was included as a second sensitizer in order to more closely simulate natural environmental conditions. MH quenches excited singlet and triplet states of Rf, with rate constants close to the diffusion limit. The herbicide and dissolved molecular oxygen competitively quench triplet excited Rf. As a consequence the reactive oxygen species (ROS), superoxide radical anion (O2(-·)), hydrogen peroxide (H2O2) and singlet molecular oxygen (O2((1)Δg)) are produced by electron- and energy-transfer processes, respectively, as demonstrated by auxiliary experiments employing selective auxiliary quenchers and the exclusive O2((1)Δg) generator Rose Bengal (RB). As a global result, the photodegradation of Rf is retarded, whereas MH is degraded by the generated ROS. The bacteria Pseudomonas aeruginosa (Ps) and Bacillus subtilis (Bs), recognized as contaminants surface-water and soil and microbial antagonists of phytopathogenic, were used in the microbiological experiments. Results of the individual incubation of both bacteria in in the presence of MH indicate a stimulation on the Ps growth, implying the biodegradation of the herbicide, whereas MH only exerted a bacteriostatic effect on Bs., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We report on the photostability of a mixture of vitamins B6 and B2 (riboflavin, Rf) upon visible light irradiation and on the possible role of the vitamin B6 family (B6D) as deactivators of reactive oxygen species (ROS). The work is a systematic kinetic and mechanistic study under conditions in which only Rf absorbs photoirradiation. Pyridoxine, pyridoxal hydrochloride, pyridoxal phosphate and pyridoxamine dihydrochloride were studied as representative members of the vitamin B6 family. The visible light irradiation of dissolved Rf and B6D in pH 7.4 aqueous medium under aerobic conditions induces photoprocesses that mainly produce B6D degradation. The overall oxidative mechanism involves the participation of ROS. Photogenerated (3)Rf* is quenched either by oxygen, giving rise to O(2)((1)Δ(g)) by electronic energy transfer to dissolved ground state oxygen, or by B6D yielding, through an electron transfer process, the neutral radical RfH˙, and O(2)˙(-) in an subsequent step. B6D act as quenchers of O(2)((1)Δ(g)) and O(2)˙(-), the former in a totally reactive event that also inhibits Rf photoconsumption. The common chromophoric moiety of B6D represented by 3-hydroxypyridine, constitutes an excellent model that mimics the kinetic behavior of the vitamin as an antioxidant towards Rf-generated ROS. The protein lysozyme, taken as an O(2)((1)Δ(g))-mediated oxidizable biological target, is photoprotected by B6D from Rf-sensitized photodegradation through the quenching of electronically excited triplet state of the pigment, in a process that competes with O(2)((1)Δ(g)) generation.

Kinetics and mechanism of photoprocesses generated by visible light-irradiation of the system riboflavin (Rf, vitamin B2) plus Thiamine (Th) and Thiamine pyrophosphate (ThDP), representing vitamin B1, was studied in pH 7 water. A weak dark complex vitamin B2-vitamin B1, with a mean value of 4 ± 0.4 M(-1) is formed. An intricate mechanism of competitive reactions operates upon photoirradiation, being the light only absorbed by Rf. Th and ThDP quench excited singlet and triplet states of Rf, with rate constants in the order of 10(9) and 10(6 ) M(-1 ) s(-1), respectively. With Vitamin B1 in a concentration similar to that of dissolved molecular oxygen in water, the quenching of triplet excited Rf by the latter is highly predominant, resulting in the generation of O(2)((1)Δ(g)). Superoxide radical anion was not detected under work conditions. A relatively slow O(2)((1)Δ(g))-mediated photodegradation of Th and ThDP was observed. Nevertheless, Th and especially ThDP behave as efficient physical deactivators of O(2)((1)Δ(g)). The thiazol structure in vitamin B1 appears as a good scavenger of this reactive oxygen species. This characteristic, that presents at vitamin B1 as a potential photoprotector of biological entities against O(2)((1)Δ(g)) attack, was been experimentally confirmed employing the protein lisozime as a photo-oxidizable target., (© 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.)

A new dye, SSD1, featuring two donor/acceptor chromophores aligned in a spiro configuration with two anchoring groups separated at a distance of 10.05 A (closely matching the distance between the adsorption sites of the anatase TiO(2) surface) undergoes efficient dye adherence on TiO(2) films. A dye-sensitized solar cell incorporating SSD1 exhibited a short-circuit current of 8.9 mA cm(-2), an open-circuit voltage of 0.63 V, a fill factor of 0.67, and a power conversion efficiency of 3.75%.