As a molecular spectroscopist, my research interests lie in using electromagnetic radiation to probe details of the molecular structure of molecules. Predominately, my research group makes use of infrared (vibrational) and nuclear magnetic resonance (nuclear spin) spectroscopies to study structural features in organic and bio-organic molecules. Currently we have two main areas of emphasis.

    Structural studies of natural products: For many years we have studied the bio-active compounds extracted from medicinal plants. Such plants are, or have been, utilized by indigenous people in various countries as herbal remedies to help treat and cure certain maladies. Using bio-activity guided methods of isolation and purification, we have determined the structures of many compounds that show activity against bacteria, fungi, cancer cell lines and other bio-assays. More recently we have investigated the role that microscopic entities (endophytes) found within plant cell walls have on the medicinal properties of plants. These microbes (fungi and bacteria) appear to exist symbiotically with the plant host, and they synthesize chemical compounds, many of which have bio-active properties. By sterilizing the outside of a leaf or stem, and cutting open the plant cells, we can induce the microbes to grow on nutrient-rich media in the laboratory, where they synthesize the chemicals in greater quantity. Using chromatographic methods the compounds are isolated and purified, and their structures determined using high resolution mass spectrometry and high-field nmr spectroscopy. Where crystals can be grown the structures are also studied using X-ray diffraction methods. We have studied endophytes from plants collected from many different parts of the world, including a Peruvian rain forest, Papua New Guinea highlands, Australian rain forest, and Utah desert, and we have discovered several new bio-active compounds, some of which may be of significant medicinal importance.

    Spectroscopic studies of wood and wood products: Wood is an infinitely renewable natural resource with physical and chemical properties that make it invaluable as a building and decorative material in most societies. Its polymer structure is complex and its composition and properties vary from species to species. We have used infrared spectroscopy to study the weathering of wood by light and water; to follow chemical modification of wood; to distinguish between botanical hardwoods and softwoods; to estimate the relative amounts of lignin and hemicellulose in different woods; to discover the differences in chemical composition of early and late growth in selected woods, and to discover how certain adhesives bond onto wood. Using infrared microscopy we can follow changes in the chemical composition of wood over very small regions, and using modern software we can deconvolute broad absorbances and assign the invididual component peaks to specific group vibrations of the wood polymer matrix.