Application of MALDI‐MS analysis of Rainforest chemodiversity: a keystone for biodiversity conservation and sustainable use

Abstract

Brazil hosts the largest proportion of global biodiversity and has demonstrated its commitment in conservation and sustainable use being a key negotiator of the Nagoya Protocol. The “Convention on Biological Diversity” (CBD) calls for actions to reduce extinction rates, something that according with different theories is of fundamental importance for the survival of life on Earth. Contrary to its position in the CBD meetings, Brazil approved a new Forest Code that will result in escalating deforestation, increasing the urgency to demonstrate the value of native species. Extractive-based activities of forest inhabitants are basically economical prospective activities upon the forest richness whose act harmfully against the environment. For centuries, such activity resulted in low profits, triggering a perverse logic that profit increase is necessarily linked to extraction increase. In the last decades, new strategies, as for instance the Sustainable Development Reserve Mamiraua, are showing that forest preservation can also be profitable. Considering the new paradigm of green economy, which now surrounds all this tensioned discussion, we are bringing to the eyesight of policy-makers results on biodiversity conservation research: combining floristic and chemodiversity surveys, using fast high throughput mass spectrometry screening (HT-MSS), to screen forest leaves for economically valued natural products. Matrix-assisted laser desorption/ionization (MALDI) ionizationbased machines are well known by their ability to furnish fast data and can be an important tool for HT-MSS. One of the aims of a long-term ongoing BIOTA/FAPESP research project at the Serra do Mar State Park is to understand ecophysiological traits of leaves, and MALDI-MS was an alternative to identify alkaloids as one of the nitrogen sink. Regarding the following main points: (1) analysis of plant attributed nitrogen fixation and (2) profitable policies for biodiversity conservation, we suggest the screening for alkaloids to be carried out using the leaves of the trees that are top ranked in population density lists within the forest sociology. In order to reach these aims, a set larger than 500 samples was screened for the occurrence of alkaloids and botanical identification. Classical chemical procedures were also applied to validate the results (Dragendorff, Mayer and Wagner assays). In this letter, we provide the first HT MALDI-MS and MALDI-MS/MS forest screening method to provide added value to local specimens of plants. Ionic liquid was used to get around known ionization problems of small molecules (< 1200Da) by avoiding isobaric ions formation by the matrix. Although, LC-ESI-MS is the common technique to screen small molecules, it is highly time consuming, since in six days, only 50 samples can be analyzed. Therefore, our strategy is based on the ability of MALDI to quickly screen a very large number of samples using an ionic liquid as matrix. Using this approach, we can screen up to 200 samples within a 3 h time-frame.