Plant-Derived Drugs and Drug Repurposing (Volume - 1), edited by Dr. Kavita Chahal, presents a comprehensive overview of phytopharmacological research and the therapeutic significance of plant-based compounds. The volume includes six research-rich chapters covering a wide range of bioactive plant constituents such as phenolics, alkaloids, flavonoids, saponins, and xanthones. It explores their pharmacological roles in treating allergies, cancer, microbial infections, and viral diseases. Topics include drug repurposing of phytochemicals, anti-histamine properties of plant metabolites, bioactive compounds from Xylaria fungi, and plant-derived drugs for cancer therapy. With contributions from seasoned researchers, the book integrates traditional ethnomedicine with modern pharmacology, offering a critical resource for scientists, herbal medicine practitioners, and students involved in natural product drug discovery.