The first edition of this book appeared in 1984 and covered the literature until the end of 1982 (one chapter dealt with much of 1983). The present volume is based on the literature published since then until approximately mid-1992. As before, it attempts to highlight the most important advances in all the main areas of natural products research, focusing on structure, chemistry, synthesis, and this time, where appropriate, biosynthesis. Each chapter is necessarily selective but the scope is extended by frequent citation of recent reviews. R. H. T. Contributors Dr C. Bladon Interprobe Chemical Services, Gallowhill House, Larch Avenue, Lenzie, Glasgow G66 4HX, UK Dr M. Gill University ofMelbourne, School ofChemistry, Parkville, Victoria 3052, Australia Dr K. J. Hale University College London, Chemistry Department, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ, UK Dr R. A. Hill Chemistry Department, University of Glas- gow, Glasgow G12800, UK DrJ. B. Hobbs University of British Columbia, Nucleic Acid- Protein Service Unit, c/o Biotechnology Lab- oratory, Room 237, Westbrook Building, 6174 University Boulevard, Vancouver BC, V6T 1Z3, Canada Dr D. R. Kelly University of Wales College of Cardiff, School of Chemistry and Applied Chemistry, PO Box 912, Cardiff CF1 3TB, UK DrJ. Leonard Department of Chemistry and Applied Chem- istry, University of Salford, Salford M5 4WT, UK Dr L. R. Milgrom Department of Chemistry, BruneI University, Uxbridge, Middlesex UB8 3PH, UK Ms F. O'Neill Department of Chemistry, Brunei University, Uxbridge, Middlesex UB8 3PH, UK Dr A.

The preceding volume appeared in 1987 and covered the literature up to the end of 1984. The present work extends the coverage to the end of 1994 with a sprinkling of references to 1995 papers. Nearly 900 new qui nones are described, including one or two which were overlooked previously, together with new work on older compounds. For each new quinone information is provided on the distribution, spectra, structure and chemistry, and on biosynthesis where available. Sadly, there is very little new chemistry, as structures are now elucidated almost entirely by spectroscopic methods and X-ray analysis. As always I am grateful to many colleagues who sent me papers and other information in advance of publication. 1972 and 1987 volumes are referred to as NOQ II and NOQ III, The respectively. In the spectroscopic data the notation (?) indicates that informa tion is missing or is dubious. R.H.T. Aberdeen, November 1995 1 Benzoquinones 1 New sources of p-benzoquinone are the cephalic glands of Eucera bees and 2 Arthrobacter bacteria and it is part ofthe defensive secretion ofthe caterpillar 3 Romalea guttata. However, the natural occurrence of o-benzoquinone has not been reported and is unlikely. Simple monosubstituted o-benzoquinones occur 4 only as transient metabolic intermediates. It has been shown that in the leaves of X anthium occidentale (Compositae) chlorogenic acid is in equilibrium with a small amount of the corresponding o-quinone but the latter has not been isolated."

The preceding volume appeared in 1987 and covered the literature up to the end of 1984. The present work extends the coverage to the end of 1994 with a sprinkling of references to 1995 papers. Nearly 900 new qui nones are described, including one or two which were overlooked previously, together with new work on older compounds. For each new quinone information is provided on the distribution, spectra, structure and chemistry, and on biosynthesis where available. Sadly, there is very little new chemistry, as structures are now elucidated almost entirely by spectroscopic methods and X-ray analysis. As always I am grateful to many colleagues who sent me papers and other information in advance of publication. 1972 and 1987 volumes are referred to as NOQ II and NOQ III, The respectively. In the spectroscopic data the notation (?) indicates that informa tion is missing or is dubious. R.H.T. Aberdeen, November 1995 1 Benzoquinones 1 New sources of p-benzoquinone are the cephalic glands of Eucera bees and 2 Arthrobacter bacteria and it is part ofthe defensive secretion ofthe caterpillar 3 Romalea guttata. However, the natural occurrence of o-benzoquinone has not been reported and is unlikely. Simple monosubstituted o-benzoquinones occur 4 only as transient metabolic intermediates. It has been shown that in the leaves of X anthium occidentale (Compositae) chlorogenic acid is in equilibrium with a small amount of the corresponding o-quinone but the latter has not been isolated."

The first edition of this book appeared in 1984 and covered the literature until the end of 1982 (one chapter dealt with much of 1983). The present volume is based on the literature published since then until approximately mid-1992. As before, it attempts to highlight the most important advances in all the main areas of natural products research, focusing on structure, chemistry, synthesis, and this time, where appropriate, biosynthesis. Each chapter is necessarily selective but the scope is extended by frequent citation of recent reviews. R. H. T. Contributors Dr C. Bladon Interprobe Chemical Services, Gallowhill House, Larch Avenue, Lenzie, Glasgow G66 4HX, UK Dr M. Gill University ofMelbourne, School ofChemistry, Parkville, Victoria 3052, Australia Dr K. J. Hale University College London, Chemistry Department, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ, UK Dr R. A. Hill Chemistry Department, University of Glas- gow, Glasgow G12800, UK DrJ. B. Hobbs University of British Columbia, Nucleic Acid- Protein Service Unit, c/o Biotechnology Lab- oratory, Room 237, Westbrook Building, 6174 University Boulevard, Vancouver BC, V6T 1Z3, Canada Dr D. R. Kelly University of Wales College of Cardiff, School of Chemistry and Applied Chemistry, PO Box 912, Cardiff CF1 3TB, UK DrJ. Leonard Department of Chemistry and Applied Chem- istry, University of Salford, Salford M5 4WT, UK Dr L. R. Milgrom Department of Chemistry, BruneI University, Uxbridge, Middlesex UB8 3PH, UK Ms F. O'Neill Department of Chemistry, Brunei University, Uxbridge, Middlesex UB8 3PH, UK Dr A.

This book should be of interest to organic and biological chemists in universities, professional research chemists in pharmaceutical and dye industries.