Foreword
Natural products are chemical compounds that are produced by living
organisms. In 1891, Albrecht Kossel suggested a formal division of natural
products into two subgroups: primary and secondary metabolites. Primary
metabolites – like amino acids, lipids, sugars and nucleobases – are ubiquitous
in all living organisms and are essential to life. Secondary metabolites, on
the contrary, lack these features; rather, specific secondary metabolites are
only produced by specific organisms. The chemical structure of secondary
metabolites, the result of millions of years of evolutionary processes, impart
evolutionary advantages to the organisms producing them. Some prominent
examples of secondary metabolites are well known compounds as caffeine
(coffee seeds, tea leaves), nicotine (tobacco leaves) and quinine (bark of the
so-called ‘chinchona tree’). The fact that living organisms focus on producing
only a specific set of natural products is as unique as limiting, especially
when considering medicinal applications thereof. Chemists are needed to
produce variations of these metabolites – so called analogues – that are not
found in nature, as these non-natural analogues might possess enhanced
biological activities. Furthermore, many secondary metabolites are produced
in minor quantities, which makes their isolation inefficient and expensive,
and thus limits commercial availability. Chemists can use so-called ‘total
synthesis’ to produce such molecules from readily available and abundant
feedstocks in the laboratory. The author of this book has worked in our team
on the development of a new synthetic route towards the natural product
hederagonic acid, belonging to the oleanane family. This work forms the
core of a bigger endeavor targeting other, higher oxidized members of the
oleanane family.
Univ.-Prof. Dr. Nuno Maulide
Head of the Institute of Organic Chemistry
Natural products are chemical compounds that are produced by living
organisms. In 1891, Albrecht Kossel suggested a formal division of natural
products into two subgroups: primary and secondary metabolites. Primary
metabolites – like amino acids, lipids, sugars and nucleobases – are ubiquitous
in all living organisms and are essential to life. Secondary metabolites, on
the contrary, lack these features; rather, specific secondary metabolites are
only produced by specific organisms. The chemical structure of secondary
metabolites, the result of millions of years of evolutionary processes, impart
evolutionary advantages to the organisms producing them. Some prominent
examples of secondary metabolites are well known compounds as caffeine
(coffee seeds, tea leaves), nicotine (tobacco leaves) and quinine (bark of the
so-called ‘chinchona tree’). The fact that living organisms focus on producing
only a specific set of natural products is as unique as limiting, especially
when considering medicinal applications thereof. Chemists are needed to
produce variations of these metabolites – so called analogues – that are not
found in nature, as these non-natural analogues might possess enhanced
biological activities. Furthermore, many secondary metabolites are produced
in minor quantities, which makes their isolation inefficient and expensive,
and thus limits commercial availability. Chemists can use so-called ‘total
synthesis’ to produce such molecules from readily available and abundant
feedstocks in the laboratory. The author of this book has worked in our team
on the development of a new synthetic route towards the natural product
hederagonic acid, belonging to the oleanane family. This work forms the
core of a bigger endeavor targeting other, higher oxidized members of the
oleanane family.
Univ.-Prof. Dr. Nuno Maulide
Head of the Institute of Organic Chemistry