Containing fully authenticated data on virtually all known natural products, the "Dictionary of Natural Products", main work, published in 1993 was the end result of over 12 years compilation and editing by a large team of contributors. The resulting Dictionary contains 100,000 natural products and their derivatives organized into approximately 35,000 entries. Volume 9 of the Dictionary contains the result of a thorough review of the natural product literature for the year 1992-3, the results of which are presented as a mixture of new entries and updated entries containing modified information. The following categories of natural products are covered: amino acids, peptides and protiens; carbohydrates; nucleosides and nucleotides; lipids; antibiotics; alkaloids; steroids and terpenoids; flavonoids; lignans; lichen acids; coumarins; polyacetylenes; polypyrroles; semiochemicals and other miscellaneous aliphatic compounds; and all other classes of miscellaneous metabolites. A particular feature of the Dictionary is the care which has been taken to draw and check the structure diagrams to ensure their accuracy and consistency, and to present the data within entries in a logical manner which reconciles as far as possible inconsistencies and inaccuracies in the literature, as determined by the subject editors. Careful attention has also been taken with nomenclature to ensure user-friendly access to all of the data. All of the contents are fully indexed by name, molecular formula, Chemical Abstracts Service (CAS) Registry Number and species from which isolated. An additional unique feature is the type of compound classification scheme which has been evolved for this Dictionary to list all natural products under one or more headings, bringing closely related compounds together under one index heading. Extensive references, labelled to show their content, are listed for each entry, allowing rapid location of data of a particular type, e.g. spectroscopic information. The "Dictionary of Natural Products" is a reference source on natural products, with Volume 9 (the second supplementary volume) a useful addition to keep the Dictionary up-to-date.