An insight into recent updates on analytical techniques for bioactive alkaloids

INTRODUCTION: Alkaloids represent a wide class of naturally existing nitrogen-containing organic compounds having diverse biological activities. They are primary bioactive substances extracted from diverse plant parts. Due to their diverse biological activities, they are frequently used as medicines. The alkaloids have diverse pharmacological impacts on the human body; alkaloids are used for prevention, treatment, and reduction of discomfort associated with chronic illnesses. As most alkaloids exist in plants in complex form, combined with numerous other natural plant components, it is essential to recognize and characterize these molecules using different analytical techniques. OBJECTIVES: We aimed to review the literature on the methods and protocols for the analysis of naturally occurring alkaloids. METHODS: We carried out a literature survey using the PubMed, Scopus, and Google Scholar databases and other relevant published materials. The keywords used in the searches were "alkaloids," "analytical methods," "HPLC method," "GC method," "electrochemical methods," and "bioanalytical methods," in various combinations. RESULTS: In this article, several classes of alkaloids are presented, along with their biological activities. Moreover, it includes a thorough explanation of chromatographic techniques, hyphenated techniques, electrochemical techniques, and current trending analytical methods utilized for the isolation, identification, and comprehensive characterization of alkaloids. CONCLUSIONS: The various analytical techniques play an important role in the identification as well as the characterization of various alkaloids from plants, plasma samples, and urine samples. The hyphenation of various chromatographic techniques with mass spectrometry and NMR spectroscopy plays a crucial role in the characterization of unknown compounds.