Foreword
Authors: Bull James R. 
Published: March 2014

Abstract
The natural products theme is deeply rooted in the culture of IUPAC, and the first International Symposium on the Chemistry of Natural Products (ISCNP) on 15-25 August 1960 with Sir Alexander Todd (later, Lord Todd) as President, can claim particular credit in the history of the Union. Not only did it take an early bold step toward the truly global reach that characterizes IUPAC conferences in the modern era, but it was the harbinger of numerous sponsored or Union-initiated series devoted to other areas of specialization in the chemical sciences. International delegates to the inaugural event undertook the then nontrivial journey to Melbourne, Canberra, and Sydney, Australia with an excursion to New Guinea, to participate in a scientific program, in which structural elucidation and synthesis were dominant themes, and most familiar modern tools and techniques were still in their infancy. Natural products lore still celebrates the names of certain pioneers who contributed to that first program.
As a series, this hardy biennial has since been hosted throughout the world, and has faithfully served a huge international community of scientists engaged in every conceivable aspect of natural products chemistry. The terms of reference for the ISCNP series have recently been adapted following a decision to merge with the younger series of International Conferences on Biodiversity (ICOB). This step was inaugurated with ISCNP-24/ICOB-4, which was held in New Delhi, India on 26-31 January 2004; &lt;http://www.iupac.org/publications/pac/2005/7701/index.html&gt;. The change exemplifies the evolving nature of the subject, and its ongoing appeal to scientists engaged in exploring and developing less familiar disciplinary interfaces, as well as traditional mainstream areas. It is thus unsurprising that natural products should feature as a Special Topic theme for a second time in the recent history of Pure and Applied Chemistry (PAC); see &lt;http://www.iupac.org/publications/pac/2003/7502/ index.html&gt; for a collection of papers based upon presentations at ISCNP-23, held in Florence, Italy on 28 July-02 August 2002. That program featured fresh insights into proteomics, genetics, and molecular biology, in a trend that ISCNP-25/ICOB-5 has continued to develop, with coverage of related and new features of bioactivity at the molecular level and chemical biological themes, whilst also paying homage to enduring favorites such as structure and synthesis.
What is a Special Topic? The concept was introduced as a device to publicize and promote new and emerging principles and practice in all branches of chemical sciences, through the pages of PAC; &lt;http://www.iupac.org/publications/pac/index.html#si&gt;. Themes may be selected from inaugural events or special IUPAC projects, but equally, may identify themselves as dynamic and widely practiced areas of science presently covered by regular IUPAC-sponsored series. Important criteria obviously include relevance, topicality, and readership expectations. Publication projects arising from the Special Topics initiative generally continue to achieve gratifyingly favourable citation profiles, and thereby support the view that they fulfil an important need.
It is noteworthy that the Kyoto meeting represents the third occasion that the series has been hosted in Japan, the home of some quite extraordinary manifestations of natural products and biodiversity, as well as some of the outstanding practitioners of the subject. The program of ISCNP-25/ICOB-5 rightly captures some of this local character, but is also a fully representative expression of the international participation and appeal that traditionally characterizes the series. It is a pleasure to acknowledge the able and enthusiastic support of the Conference Editor, Prof. Hideo Kigoshi, in preparing this Special Topic issue of 27 topical papers based upon program presentations. The collection aspires to offer an enduring archival record of a subject that continues to reinvent itself, and to astound and challenge its practitioners with the apparently boundless molecular riches of the biosphere.

James R. Bull

Scientific Editor