Innovative Extraction Techniques and Hyphenated Instrument Configuration for Complex Matrices Analysis

The interest in complex analytical techniques has been growing in the last period due to the renewed necessity for analyzing complex biological matrices like herbal medicinal products and biological fluids. This particular necessity has developed in the area of life/medical sciences for quality control and standardization as well as to reveal potential molecules that serve as biological markers. Natural product research has increased considerably since the ‘90s as a tool for providing new chemical entities, as a consequence of several outstanding developments in the areas of separation methods, spectroscopic techniques, and a broad range of sensitive bioassays. From a historical point of view, natural product-based drug discovery has been dominated by medicinal plants as original matrices for the discovery of new compounds [1]. Traditionally used medicinal plants were the first source of medicines and have maintained a crucial role in drug discovery and development [2]. Furthermore, extraction is considered a fundamental process used for the separation and recovery of active molecules from different matrices and converts the real matrix into a sample suitable for subsequent analytical procedures [3]. Extraction is crucial when it comes to targeting a specific class of natural molecules, as physicochemical properties of natural products are extremely variable. Furthermore, extraction techniques have to be adapted to plant parts and types of tissue matrices, as in many cases some classes of natural biomolecules can be mostly found in specific plant parts, i.e, rhizomes, flowers, leaves, stigmas, buds, etc. As such, various extraction methods have been developed and tested to meet all the issues raised above [3]. The Special Issue gathered in this printed book was proposed by three Guest Editors, all of them professors of pharmaceutical sciences, one analytical chemist and two pharmacists, doing research and teaching in the fields of analytical chemistry, medicinal chemistry, and pharmaceutical botany. This along with the description of the Special Issue allowed us to consider a broad range of submissions and concluded with the selection of 18 manuscripts after being peer-reviewed. The published papers (one review and 17 original research articles) were submitted by research groups from different countries that fit the aims and scopes of our Special Issue [4]. We would like to thank all contributors and colleagues who chose to publish their works here as well as the reviewers who dedicated their time, effort, and expertise to evaluating the submissions and assuring the high quality of the published work. We would also like to thank the publisher MDPI and the editorial staff of the journal for their constant and professional support as well as for their invitation to edit this Special Issue [4]. Finally, we would like to thank all authors and readers and we hope that the content of this book will offer new perspectives and ideas to initiate and continue research further. References 1. Ahn, K. The worldwide trend of using botanical drugs and strategies for developing global drugs. BMB Rep. 2017, 50, 111–116. 2. Newman, D.J.; Cragg, G.M. Natural Products as Sources of New Drugs from 1981 to 2014. J. Nat. Prod. 2016, 79, 629–661, doi:10.1021/acs.jnatprod.5b01055. 3. Belwal, T.; Ezzat, S.M.; Rastrelli, L.; Bhatt, I.D.; Daglia, M.; Baldi, A.; Prasad, H.; Erdogan, I.; Kumar, J. A critical analysis of extraction techniques used for botanicals: Trends, priorities, industrial uses and optimization strategies. Trends Anal. Chem. 2018, 100, 82–102, doi:10.1016/j.trac.2017.12.018. 4. Locatelli, M.; Carradori, S.; Mocan, A. Innovative Extraction Techniques and Hyphenated Instrument Configuration for Complex Matrices Analysis. Molecules 2018, 23, 2391, doi:10.3390/molecules23092391.