Dr. Mahendra Rai is presently a visiting Professor at the Department of Microbiology, Nicolaus Copernicus University, Torun, Poland. Formerly he was Professor and Head of department of Biotechnology, SGB Amravati University, Maharashtra state, India. He was a visiting scientist at the University of Geneva, Debrecen University, Hungary; University of Campinas, Brazil; VSB Technical University of Ostrava, Czech Republic, and National University of Rosario, Argentina, and University of Sao Paulo. He has published more than 425 research papers in national and international journals. In addition, he has edited/authored more than 62 books and 6 patents. Recently, he has been featured in Stanford's list of top 2% scientists under Nanoscience and Nanotechnology. Dr. Chistiane M. Feitosa is a Professor at the Department of Chemistry, Federal University of Piaui, Teresina, Brazil. Her research areas include pharmacology, natural products and their secondary metabolites with the potential for treatment of neurodegenerative diseases and antimicrobials. She has published more than 55 research papers in national and international journals. In addition, she has edited/authored more than 12 books /chapters from eminent publishers like CRC press/ Taylor and Francis and also 5 patents.