Strategies for the primary recovery of bioactive molecules using Aqueous Two-Phase Systems

Abstract

Nature has historically been a source of a wide variety of bioactive molecules. They play a relevant role in many fields, such as the pharmaceutical, agrochemical, biotechnological, cosmetic and food industries. Almost half of the products in the drug market are either bioactive natural molecules or derived from them. Appropriate extraction and isolation steps are crucial for downstream processing and sample preparation methods of natural products. There are several available methods for the extraction and isolation of bioactive molecules from different natural sources, however they are often associated with major drawbacks. To overcome some of these, aqueous two-phase systems (ATPS) are an attractive alternative.

This thesis presents the application of ATPS as an alternative method for the recovery of different bioactive molecules from complex natural sources: laccase produced by the fungus Pleurotus ostreatus, metalloproteases (MPs) and phospholipases A2 (PLA2) present in the venom of the snake Crotalus molossus nigrescens and phenolic compounds from the medicinal plant Sedum dendroideum. There is no information about the extraction and isolation of the majority of these molecules from the previously mentioned matrices using ATPS. Different types of systems were evaluated to optimize the recovery of such biomolecules. Also, the effect of different system parameters such as volume ratio (VR), tie line length (TLL), polymer molecular weight, pH and sodium chloride (NaCl) addition were explored. All of the bioactive molecules were efficiently recovered from their natural sources, demonstrating the versatility of ATPS. Furthermore, biological activity of these biomolecules was retained, or even increased, after ATPS extraction process. These findings contribute to the establishment of a simple, rapid and cost-effective alternative method for the extraction and isolation of the studied biomolecules and potentially aid their study and application in a wide range of fields.