Synthesis, photophysical characterisation and testing of a new type of photobleaching agent

The purpose of this work, funded by Procter and Gamble (P&G), was the synthesis, photophysical characterization and testing of thioxanthone (TX) derivatives as photobleaching agents (PBA) for use in laundry products (Figure 1). Figure 1 Photobleaching agent process: sunlight can promote the activation of PBA adsorbed on a not clean cloth, thanks to an efficient intersystem crossing and high rate of oxygen quenching it is possible to create singlet oxygen and continue the cleaning process during the drying Procter and Gamble selected thioxanthone for its photophysical characteristics and high potential to be the next PBA generation. Firstly the main electronic absorption transition occurs in the near ultraviolet region; the solid compound is pale yellow and solution colourless, a distinct advantage compared to the PBA currently in use. Another important property is the efficient formation by photosensitisation of singlet oxygen. Thioxanthone is a good photosensitiser and has been used for almost a century in photodynamic therapy. Finally, the overall cost for TX production and storage is drastically lower compared to the available commercial PBA. Unfortunately, TX has a poor solubility in water which limits the concentration in solution. In this work, ten new thioxanthone derivatives have been synthesised with the intent to maintain TX photophysical properties and increase water solubility. The synthetic pathways proposed in this work aim to be cheap, simple and highly reproducible, an advantage compared to current PBA. P&G started a collaboration with Durham University aiming to overcome these disadvantages and to have a full understanding of the photophysical behaviour of the potential new PBA. The achievement of this project is articulated and explained in this manuscripts as follow: 1. Introduction: historical role and evolution of detergents, state of the art on available commercial PBA, literature review on thioxanthone (TX) 2. Experimental: overview of equipment used for the photophysical characterization of derivatives (Chapter 4) and during tests performed at P&G (Chapter 5) 3. Synthesis: description of the synthetic route used to produce thioxanthone derivatives 4. Photophysical characterization of thioxanthone derivatives: a full analysis of photophysical behaviour of thioxanthone derivatives, interaction with crocin as stain simulator and detergents 5. Thioxanthone derivatives as Photobleaching Agents: a series of tests which simulate, in a small scale, the washing and drying process in the presence of current PBA and a selection of thioxanthone derivatives 6. The behaviour of thioxanthone upon acidification: an extensive analysis on the photophysical property on thioxanthone in the presence of H2SO4 and TFA 7. Conclusions and future step

BIO-INCROP - Final report

APPLE • Apple replant disease in central Europe has a consistent biotic origin which is responsible for about 30% of growth reduction in multi-generation orchards. Cylindrocarpon-like fungi and Pythium spp. were shown to be primarily responsible for plant growth reduction, which was confirmed as main indicator of apple replant disease. • Pyrosequencing analysis of rhizospheric microbial communities associated to replanted orchards confirmed that Cylindrocarpon-like fungi are largely associated to replant disease; however, it also evidenced that several bacterial and fungal genera indigenous to replanted orchards are positively correlated to plant growth. This suggested that many are the indigenous resource to be exploited for increasing plant growth/soil health in permanent cropping systems. • Pre-plant treatment with locally available composts of different origin showed a variable effect in plant growth. Composted mushroom substrate gave the best performance in four countries involved in the evaluation. The phytotoxicity effect, due to high salt content in composts, represents a limit that can be overcome by setting up suitable amendment doses. • Cover crops in pre-plant can induce microbial changes at the rhizosphere level of the subsequent apple orchards, despite soil microbial resilience due to long-term management of soil. However, one only pre-plant break with cover crop is not sufficient to mitigate replant disease in the subsequent newly planted trees. • Commercially available bio-formulates in each country involved in the project and selected for their common ingredients (Trichoderma spp., Bacillus, Paecilomyces and other strain active in biocontrol) did not result overall effective in reducing common apple replant disease, although two specific products out of ten selected in all cases gave the highest plant growth. To the contrary, two out of ten bio-formulates were effective in controlling Phytophthora cactorum attack. • Among the non-chemical options tested for reducing replant problems, soil steam application in pre-plant gave promising results after one-year field trials. CITRUS • Phytophthora citrophtora was mainly responsible for citrus degradation in Mediterranean countries. A study on conversion to organic cultivation performed in a large degraded citrus orchards in Valencia province (Spain) gave 25% of plants dead for Phytophthora attack within 2-year after transplant. • Growth response of newly planted trees to different soil management (including solarisation, cover crops and organic amendments) and the application of ten commercially available bioformulates (biofungicides, nematocides and biostimulants and active principles) in degraded citrus orchards was not significantly affected by any pre-plant treatments. • Techniques based on the application of organic matter shortly before replanting are not successful in total control of Phytophthora attack in citrus degraded orchards, but do reduce damage to soil organic matter and biological activity compared to more aggressive techniques such as solarisation. Vegetal covers appear to be very promising in this respect as they cause a large stimulation of biological activity in soil when applied to degraded orchards. • Soil enzymes were shown to be very useful indicators of changes in soil quality when converting degraded citrus to organic management in Mediterranean environment • Phytophthora citrophtora severity attack was successfully reduced by several bio-formulates commercially available in Turkey (especially those with Lactobacillus acidophilus and biologically active principles as their main ingredients) in controlled conditions using citrus rootstocks. However, findings of the project overall showed that, origin, type and condition of the replant soil strongly affect the effectiveness of the biological active formulate in controlling Phytophthora attack in newly planted citrus trees

BIO-INCROP

INNOVATIVE CROPPING TECHNIQUES TO INCREASE SOIL HEALTH IN ORGANIC FRUIT TREE CROP

Potential Response of Soil-Borne Fungal Pathogens Affecting Crops to a Scenario of Climate Change in Europe

A study was carried out on the potential response of soil-borne pathogens causing crop yield losses under a climate change scenario in Europe. A controlled chamber set of experiments was carried out to quantify pathogen response to temperature using pure colonies of three soil-borne fungi, representative of low (Fusarium nivale), medium-high (Athelia rolfsii) and high (Macrophomina phaseolina) temperature requirements. A generic model to simulate fungal growth response to temperature based on these experiments was developed and linked to a soil temperature model component, and to components to simulate soil water content accounting for crop water uptake of potential hosts. Pathogens relative growth was simulated over Europe using the IPCC A1B emission scenario as realization of the Hadley-CM3 global climate model, available from the European Commission and processed for use with biophysical models. The simulations resulting from using the time span centred on 2030 were compared to the baseline, centred on the year 2000, using a sample of 30 years of daily weather. The general trend of soil-borne pathogens response to the scenario of climate change is a relative increase in growth in colder areas of Europe, as a function of their temperature requirements. Projections of F. nivale in the future indicate a relative increase of this winter pathogen of wheat in Northern European countries. A. rolfsii and M. phaseolina, two soil-borne pathogens typical of warmer agricultural areas, could find more favourable conditions in areas of the Central Europe, but they differentiated in Southern Europe where A. rolfsii resulted affected by summer soil temperatures above optimum

Mid-term report for the CORE Organic II funded project. “Innovative cropping Practices to increase soil health of organic fruit tree orchards” BIO-INCROP

Activities performed in the first part of BIO-INCROP project concern five of the eight main objectives fixed in the project proposal. They are: Evaluation of soil borne pest and pathogens involved in replant disease Role of rhizospheric bacterial and fungal communities in plant health Selection of naturally available resources to increase microbial diversity and biomass Compost and organic amendments Evaluation of biologically active formulates The document reports main research results and shows main items of dissemination activity performed in the first part of the project

ENDOPHYTIC FUNGAL POPULATIONS ACTING ON SOIL SUPPRESSIVENESS IN FRUIT TREE ORCHARDS

The aim of the present study was i) to identify the soil inhabiting endophytic fungal populations having beneficial impact on crop health; ii) to identify the biological processes responsible of this functional effect. Activity was performed on fungal populations extracted from the microbial population of soil samples coming from three apple growing areas of Europe. Functionalities of Fusarium oxysporum and binucleate Rhizoctonia observed in this study are two small examples of soil biological resources that could be exploited in organic agriculture for developing innovative cropping practices

Replant problems in South Tyrol: role of fungal pathogens and microbial populations in conventional and organic apple orchards

South Tyrol, the main Italian apple growing area, is characterised by an highly intensive soil cultivation. Previous investigations shows the existence of replant disorders although it has not been evaluated which are the main causes. A survey has been carried out in this area with two main aims I) to evaluate the role of soil borne pathogens in apple replant disease and II) to evaluate the effect of soil management toward soil borne pathogens causing replant diseases. The experimental sites were chosen in order to obtain three couples of contiguous conventional and organic apple orchards. Soil sickness test with young apple plants gave a significant growth reduction in all soil samples if compared to a peat control. Among all root colonising fungi (Fusarium oxysporum, F. solani, Aphanomyces sp., Cy/incrocarpon sp., Rhizoctonia sp. and Pythium sp.) some Rhizoctonia solani strains and all Pythium spp. were the most pathogenic. In all cases organic management seems to reduce the soil sickness severity caused by root rot fungal pathogens

Venturi mask is the pioneer of High-Flow Oxygen Therapy Concepts

Oxygen therapy should be carefully considered and monitored because, as any other medications, it can cause harm to patients, if used inappropriately. This paper focus on the distinction between low-flow and high-flow oxygen therapy. A discussion about Venturi system for oxygen administration is carried on, given that some authors include it in the low-flow devices group despite its characteristics to deliver high flow therapy

Use of Brassica Plants in the Phytoremediation and Biofumigation Processes

In recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the biological quality of soil, which is why pesticides and fertilizers are being used in ever-larger quantities. The environmentally friendly solutions to these problems are phytoremediation, which is a technology that cleanses the soil of heavy metals, and biofumigation, a process that helps to protect crops using natural plant compounds. So far, these methods have only been used separately; however, research on a technology that combines them both using white cabbage has been carried out