Prof. Dr. Till Opatz: Learning from Nature – New materials and active ingredients from natural sources

Scientists at Mainz University find inspiration in natural products and are investigating new substances and sustainable production processes.

The biosphere is an inexhaustible source of inspiration for organic chemists. Billions of years of evolution have produced complex molecules, which often play a well-defined role in the organism that generated them by protecting their producer from infections or predators. Natural products and compounds derived from or inspired by them have not only proven to be successful in the pharmaceuticals industry but are also used for crop protection and as food preservatives.

At the Rhineland-Palatinate Natural Products Research Centre at the Johannes Gutenberg University of Mainz, the detailed molecular structure of previously unknown natural products is being investigated using modern spectroscopic techniques. This information may prove to be the starting point for chemical synthesis, as such substances isolated from natural materials often cannot be obtained in sufficient quantities. With knowledge of the biological effect of these substances, provided by collaboration partners such as the Institute of Biotechnology and Drug Research (IBWF), so-called structure-activity relationships are being obtained, which sometimes even permit the identification of  the effectiveness of essential structural elements. In addition, the molecular structure often permits to draw conclusions on how the producing organism has synthesised the substance.

Besides the synthesis of the actual natural product, related compounds are also produced chemically. These are also evaluated for their biological effectiveness. At the same time, the synthetic chemists must develop new processes in order to re-create the often complex molecular architecture, which means that nature serves as a source of inspiration in several respects at the same time.

The topic of the search for active substances in and with nature combines chemistry with pharmaceuticals, medicine and biol­ogy and is of great interest to students. Numerous new pharmaceutical principles have already been developed, for example with regard to anti-inflammatory natural substances from fungi. Several patents in the field of pest control have already been submitted for registration in cooperation with industry.

 

Another similarly interesting aspect of natural products was introduced by the Chemical Biomedicine Initiative at the Institute for Organic Chemistry and the Faculty of Medicine of Johannes Gutenberg University (Prof. Roland Stauber). Both are supported by the Carl Zeiss Foundation. In this case, the search for new bioactive substances from nature produced innovative approaches to the alternative use of natural raw materials which can be used both to synthesise pharmaceutically active substances and for the resource-friendly production of materials and specialty chemicals substances. In cooperation with researchers from the USA and South Africa, these approaches are now being developed in Mainz.

While traditional synthetic chemistry uses fossil carbon sources such as petroleum, natural gas and coal almost exclusively, wood as a renewable raw material offers a largely unexploited potential. Today, an important group of chemicals – the so-called aromatic compounds – are usually produced from petro-chemicals such as petroleum; how­ever, they are also contained in a modified form in the wood of coniferous and decidous trees. While petroleum products can be converted to this form, this requires the very complex, re-introduction of structural elements which have disappeared over millions of years from the former biomass. However, it is precisely this particular form – that is similar to wood’s ingredients – which forms the structural basis of many natural products.

Thus, the team of researchers of Professor Till Opatz in Mainz, together with Professor A. J. Arduengo III and his team of researchers from the University of Tuscaloosa, Alabama (USA), succeeded in 2016 in first synthesising the natural substance Ilicifolin B, which is potentially active against cancer cells. In contrast to conventional practice, basic fossil materials were not used; instead, the molecular structure of this natural product from a South American shrub was constructed using solely wood-based, and hence renewable, raw materials. A similar successful approach was implemented for a morphine-related painkiller, which is normally obtained from opium poppies.

This new approach, which – similar to the term “petrochemistry” – may be referred to as xylochemistry (from the Greek “xylos” meaning “wood”), makes further processes possible. Recently – again in close cooperation between Mainz and Tus­ca­­­­loosa – light­­fast textile dyes and plastics were produced using xylochemical methods without utilising fossil resources. Xylochemical approaches thus form a bridge from natural products chemistry to the material sciences and open up numerous other areas of use. For example, the large-scale production of key components of automotive paints may prove to be a rewarding target, as may be the production of stabilisers, softeners and optical brighteners. This could open up new possibilities of environmentally friendly and CO2-neutral production of interest to domestic industry.

Prof. Dr. Till Opatz
Till Opatz was born in 1973. He studied chemistry in Frankfurt am Main before completing a doctorate at the Johannes Gutenberg University of Mainz. After a period in the Netherlands, he completed his professorial “Habilitation” thesis in Mainz and initially took up a professorship in Hamburg before returning to Mainz in 2010. Since then he has headed the Rhineland-Palatinate Natural Products Research Centre.