Natural Products: Advances in Isolation, Characterization, Biological Activities, and Plant Protection Applications.

Natural products derived from plants and microorganisms remain promising alternatives to synthetic chemicals and conventional substances across a wide range of fields, including pharmaceuticals, agriculture, and industry. They also play an important role in the development of sustainable biopesticides and biofertilizers. Chemically, natural products can be grouped into overlapping structural and biosynthetic categories, including alkaloids, terpenoids, flavonoids, glycosides, saponins, and polyketides. Each group reflects distinct chemical characteristics and associated biological functions. This overview highlights the main findings from the Molecules Special Issue: "Natural Products: Isolation, Analysis and Biological Activity, 2nd Edition", focusing on three categories: (i) plant protection, plant health, and plant biotechnology; (ii) functional foods and health-promoting formulations; and (iii) therapeutic natural products and derivatives. Exploring the mechanisms of action of natural products is essential for ensuring safety and optimizing sustainable resource use. This understanding drives critical innovations across drug discovery and materials science. Ultimately, such research reinforces their cross-disciplinary significance for advancing human health and promoting environmental sustainability.