A comprehensive study on nest materials of Vespa crabro and Polistes dominula: Chemical properties and biological characterization with antioxidant and antimicrobial activity

A comprehensive study was conducted on the nest materials of Vespa crabro (Linnaeus, 1758) and Polistes dominula (Christ, 1791) (Hymenoptera: Vespidae) of Black Sea region origin. Study of the physicochemical and surface properties, determination of the chemical-structural features, and bioactivity studies of the samples were carried out in four planned steps. In the first step, the physicochemical properties, the ratio of the plant material to the oral secretions, the water absorption and oil percentages as well as thermal analyses were researched. In the second step, observation of the surfaces under a light microscope and scanning electron microscope uncovered the surface properties. In the third step, chemical studies of the extracts from the solvents of different polarities (methanol, acetone and petroleum benzine) revealed the molecular functionalities of the biocompounds which were inside the materials using UV-Vis., FTIR, GC-MS, and elemental analysis techniques. In the last stage, the extracts underwent bioactivity research of antimicrobial and antioxidant screening with a phytochemical search of phenolic compound determination. The obtained data revealed the nesting properties and differences between the two species. In the P. dominula nest, the plant fibers were long and were glued regularly, and some were cross-linked and thick while in the V. crabro nest, the plant fibers were fine, grooved, thin and disordered. The comb surface of V. crabro was larger than that of P. dominula with minimum values of 75 and 37.5cm(2), respectively. The bioactivity research of the materials showed the high potential of the antimicrobial and antioxidant properties of some nests' extracts. In all the extracts, the samples belonging to the V. crabro nest material had the highest biological activity.