ABSTRACT Novel Synthetic Routes to 14(3,17(3-Propano and Cyclopenta[14,15] 19-Norsteroids Pia Gail Mountford, Chemistry Department, University of Cape Town, Rondebosch 7700, February 1995 An efficient synthetic strategy for the stereoselective introduction of a 14(3-allyl group to estrone 3-methyl ether has been developed. The approach involves regio- and stereoselective Diets-Alder cycloaddition of acrolein to 3-methoxyestra-1,3,5(10),14,16- pentaen-17-yl acetate. Hydride reduction of the f...
Abstract Cycloadditions of steroidal 14,16-dienes with ketene equivalents were investigated, as routes to estradiol and estriol analogues. The cycloadduct of 3-methoxyestra- 1,3,5(10), 14,16-pentaen-17-yl acetate and 2-chloroacrylonitrile underwent an unprecedented tandem rearrangement, on attempted alkaline hydrolysis to the corresponding ketone. This product, obtained in ca. 90% yield, was formulated as (161R)-3-methoxy-17-oxo-158,161-cyclo-14,168-ethano-148-estra-1,3,5(10)-triene-16L carbo...
Abstract The structures of some non-cellulosic S-Q-Glycans from three plant sources have been investigated and each was found to be characterised by linked D-pyranosyl a main chain consisting of S-(1-44)- sugars. The polysaccharides were, however, different in structural features in a manner apparently related to their respective locations within the organs of the plants concerned. The polysaccharides were isolated and purified using standard fractionation methods including chromatographic te...
Thesis on A Study Of Oil Bearing Seeds From Some Indigenous Plants. The everyday use of fats and oils can roughly be divided into the following two classes. Firstly, they are one of the basic ingredients) directly and indirectly, in the diet of the, human being. .Secondly, they are used for soap-making, for the manufacture of paints and other drying vehicles, and also for making greases and other miscellaneous, industrial products. For each purpose a different type ·of oil is needed, so tha...
ABSTRACT In sub-Saharan Africa, the high infant mortality is mainly due to diarrhoea, respiratory infections, typhoid and measles. The control of these diseases relies heavily on the use of synthetic drugs. However, due to the high cost of these drugs and increased bacterial resistance to available anti-biotics, their use is increasingly becoming unpopular. Plant– derived herbal medicines are feasible alternatives that can be used to reduce incidence of these diseases. Since they are readi...
ABSTRACT Polyphenols are the primary compounds responsible for the health benefits of tea, including its antioxidant and anti-inflammatory properties. Caffeine contributes to tea’s stimulant properties, while gallic acid and polyphenols contributes to its antioxidant properties. Most of the High Performance Liquid Chromatography (HPLC) methods used for the determination of tea biochemicals include gradient elution systems which involve expensive instrumentation. The aim of this study was t...
ABSTRACT Karate and Pyagro are insecticides currently registered and used in Kenya for control of several insect and mite pests in diverse crops. They are emulsifiable concentrate formulations of the active ingredients lambda-cyhalothrin (Karate) and Pyrethrins (Pyagro). This study established residue levels for lambda-cyhalothrin and Pyrethrins in fresh tea leaves, black tea and brewed tea. The study evaluated the effect of tea preparation procedures on pesticide residue levels in tea and mo...
ABSTRACT Particulate emissions and organic volatiles produced by incomplete combustion processes have attracted the attention of many environmental experts. Consequently, increasing concern has been directed towards the study of human health problems caused by carcinogenic and mutagenic soot components such as polycyclic aromatic hydrocarbons (PAHs) and polyenes from various combustion systems. Soot from many combustion systems are well-known precursors for numerous toxicological impacts in t...
ABSTRACT The diseases transmitted by mosquito continue to be rampant and in most case fatal especially in the developing countries. Mosquito is the main vector for malaria. Malaria is a scourge and according to the World Health Organisation (WHO) estimations, over 40% of the world population remain exposed to malaria. In Kenya, about 25,000 children die of malaria each year; although the actual number of deaths is unknown since most of them occur at home. Since prevention is better than cure...
ABSTRACT Life threatening diseases like, cancer, diabetes, cardiovascular and neurodegenerative diseases have been linked to oxidative stress in the human body. Oxidative stress results from the uncontrolled generation of reactive oxygen species (ROS) in the body. Naturally, the normal body regulates ROS through in situ production of antioxidants. However, the human body is not capable of quenching ROS exceeding a certain level and this can result in oxidative stress. Hence the need of exogen...
Fungi, especially higher ones, have received a lot of attention in the recent decades due to the advances of biotechnological techniques. This is because secondary metabolism in fungal biotechnological cultures is manipulable and produces an array of compounds with diverse as well as novel chemical and biological properties. The activities can be taped into to address the myriad problems afflicting local communities in Kenya especially in agrochemical and medical sectors. Disease burden ...
ABSTRACT Plants are a potential source of antimicrobial compounds. In this study, a plant from the family Simaroubaceae, Harrisonia abyssinica, traditionally used to treat a number of diseases was used. Research has been carried out on its stem bark, root bark and leaves and a number of chemical constituents have been isolated but no research has been carried out on its berries. Therefore the berries of this plant were chosen in order to investigate for antimicrobial compounds. The berries o...
Malaria caused by Plasmodium parasite is at the moment the one of the highest killer disease in the tropics. In developing countries, where malaria is one of the most prevalent diseases, some people still rely on traditional medicine for the treatment of this disease. In the present study an ethnobotanical survey was conducted to document antimalarial medicinal plants. In vitro antiplasmodial and in vivo toxicity activities were carried out on crude root extracts and on the isolated pure...
ABSTRACT Malaria caused by Plasmodium parasite is at the moment the one of the highest killer disease in the tropics. In developing countries, where malaria is one of the most prevalent diseases, some people still rely on traditional medicine for the treatment of this disease. In the present study an ethnobotanical survey was conducted to document antimalarial medicinal plants. In vitro antiplasmodial and in vivo toxicity activities were carried out on crude root extracts and on the isolated ...