This work is essentially an investigation of non-convective moisture movement as the result of a temperature gradient in hygroscopic porous materials, in particular, cocoa beans. The aim of the research has been to determine experimentally the bulk moisture diffusion coefficient for cocoa, and, by quantifying it, to investigate the contribution of such diffusion to wetting and mould damage that has occurred on the surface of cargoes during shipment from West Africa to Northern Europe.

Studies have been conducted on the calcinogenic plant Trisetum flavescens in order to determine the physiological actions and chemical nature of the toxic substance or substances. An organic soluble substance was extracted and purified and shown to promote intestinal phosphate transport and increase plasma phosphate levels. This factor was shown to influence the movement of phosphate from the serosa to the bloodstream but not direct uptake from the intestinal lumen. This substance was found to be unlike vitamin D3 or its hydroxy - metabolites in that it did not promote intestinal calcium transport, or bone resorption when studied in vitro. This substance did decrease plasma alkaline phosphatase levels in vitamin D3-deficient chicks however. An aqueous soluble extract was partially purified on a Sephadex column and found to promote an increase in plasma phosphate in both vitamin D3-replete and vitamin D3-deficient chicks. The extract was also able to Influence intestinal phosphate transport in a similar manner to the organic solvent soluble phosphataemic factor. As both the aqueous soluble and organic solvent soluble factors were active in vitamin D3-deficient chicks they were presumed to act upon the paracellular route for intestinal phosphate uptake. The aqueous soluble factor differed from the organic solvent soluble one in that its administration produced a dramatic decline in the plasma calcium levels of vitamin Do-deficient chicks. The aqueous soluble factor MBS without effect upon bone cultured in vitro. A second aqueous soluble extract was shown to increase intestinal transport of calcium in chicks with a metabolic deficiency of vitamin D3 caused by the inclusion of strontium in the diet. This substance appears to be able to mimic the actions of 1,25(0H)2cholecalciferol. The potent aqueous soluble phosphataemic factor is not related chemically to vitamin but has the characteristics of an aromatic indole or amine. It is concluded that the actions of these three substances in raising plasma [Ca x Pi] results in calcinosis.

A clearing and staining method using 2 stains, with one acting as a counter-stain for fungi, gave higher estimates of fungal biomass than other staining methods and it correlated well with the agar film technique. Using the method, it was possible to examine the spatial distribution of hyphae on leaves which varied between leaf types and fungal species. Improvements were made to the agar film method by optimising extraction of hyphae from leaf litter and using a tetrazolium staining technique to detect metabolically active hyphae. An indirect method for estimating fungal biomass was developed using ergosterol as a marker. Conversion factors for ergosterol and biovolume to fungal biomass were shown to vary with fungal species, age and growth conditions, but no single parameter was found which could adequately explain this. In field studies on flooded gravel pits biomass was 0.02-6.66/0 leaf dry weight depending on leaf type, biomass method and submersion time. Biomass estimated using clearing and staining was significantly correlated with ergosterol and with the agar film method; the latter gave the highest estimates. In terms of allochthonous litter inputs, fungal biomass represented 0.03-16.22 kg/ha. Studies on a number of the gravel pit lakes demonstrated variation in communities of Ingoldian fungi both between lakes and within a single lake. Correlations were found with magnesium levels and litter inputs, but not with fungal biomass in the litter or cellulose decomposition. In one lake, decomposition of litter, fungal biomass and microbial populations were followed. No differences were found in biomass when animals were excluded although this influenced Ingoldian fungi. Higher numbers of Ingoldian fungi correlated with weight losses and biomass , and a competitive hierarchy was suggested to explain changes in fungal populations during decomposition.

Diabetes is an endocrine disease characterised by a chronic increase in blood sugar levels caused by a deficiency of insulin production, which leads to type 1 diabetes, or by a loss of tissue response to insulin, which leads to type 2 diabetes. The disease leads to disruption of metabolism, vascular damage and damage to the nervous system, as well as damage to other organs and systems. Type 2 diabetes is becoming more common throughout the world, due to poor nutrition and lifestyle, and genetic background. Efforts have accordingly been increased towards developing and refining treatments as well as to addressing the underlying causes of the disease. Many parts of the world have a documented history of the use of plants to treat diabetes, and these can be an attractive, local, alternative to expensive pharmaceutical medicines. Accordingly there is an increasing interest in identifying new phytochemicals with proven pharmacological effects on diabetes. The tree Moringa peregrina is commonly found throughout the Middle East and the oil from its seeds has been used for thousands of years. Other members of the Moringa family have recorded anti-diabetic family and Moringa peregrina was chosen for investigation in this work with the aim of characterising anti-diabetic activity from its leaves. Six extracts were prepared using solvents water, methanol, butanol, ethyl acetate, chloroform and hexane, based on standard extraction techniques. The study was designed to assess the effect of these six extracts on the uptake of glucose in a human hepatoma cell line (HepG2) using a well-studied fluorescent derivative of glucose, 2-2-[N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino glucose (2-NBDG). The cells can take up 2-NBDG instead of glucose via glucose transporters and its uptake is indicative of the capacity of cells to take up glucose, i.e. of the number of active glucose transporters on the cell surface. The results revealed that the extracts prepared with ethyl acetate and chloroform increased glucose uptake significantly more than the other extracts. Moreover the effects of the extracts were rapid, with a one hour treatment producing a similar stimulation to a 24 hour treatment. These data were confirmed in a second method of investigation of the hypoglycaemic effect of the extracts, by measuring consumption of glucose from cell culture medium. A preliminary assessment of the effect of active extracts on expression of the main glucose transporter of HepG2 cells, GLUT1, by western blotting indicated no large changes in expression. Dietary phytoestrogens have been shown to play a beneficial role in obesity and diabetes, so the second part of this study investigated the effect of phytoestrogens on glucose uptake. Three phytoestrogens (daidzein, formonontein and genestin, which are naturally occurring isoflavones) were chosen. HepG2 cells showed a significant increase in glucose uptake after treatment with phytoestrogens compared to the control. In an attempt to identify the active phytochemicals that could account for the observed effects, extensive purification and characterisation of components from the ethyl acetate fraction was undertaken. Seven components were identified: (1) OEthyl 4-[(α-L-rhamnosyloxy)benzyl] thiocarbamate (E), (2) O-Butyl 4-[(α-Lrhamnosyloxy)benzyl] thiocarbamate (E), (3) 4-(α-L-Rhamnosyloxy)benzyl isothiocyanate, (4) ȕ-Sitosterol, (5) Daucosterol, (6) γ’-methyl-quercetin-3-Orutinoside (also known as isorhamnetin-3-O-rutinoside), (7) Rutin. In a final analysis an attempt was made to assess the effect of a representative set of three out of the seven components on basic metabolic activity of HepG2 cells using a Seahorse XF-24 analyser. The three components chosen were O-ethyl 4-[(α-L-rhamnosyloxy) benzyl] thiocarbamate (E), ȕ-sitosterol from the phytosterols family and Rutin. Real-time monitoring of cell metabolism by a Seahorse XF-24 auto analyser after two hours incubation with the three chosen compounds revealed that maximal respiration, non-mitochondrial respiration and spare respiratory capacity have trended towards an increase with ȕ-sitosterol and3-O-ethyl 4-[(α-Lrhamnosyloxy) benzyl] thiocarbamate (E) treatments compared to control. As no similar trends were observed in ATP production, the increased maximal respiration could increase metabolic activity at higher concentrations of glucose and account, in part for the effects observed on glucose consumption.

The project is concerned with the total synthesis of plant growth regulators related to abscisic acid (ABA). The biological activity of these plant growth regulators, ABA and Xanthoxin, and their derivatives is influenced by the stereochemistry of the double bond system in the side chain, the 2Z,4E-isomers being most potent.