Diversity in Chemical Structures and Biological Properties of Plant Alkaloids

Abstract

Phytochemicals belonging to the group of alkaloids are signature specialized metabolites endowed with countless biological activities. Plants are armored with these naturally produced nitrogenous compounds to combat numerous challenging environmental stress conditions. Traditional and modern healthcare systems have harnessed the potential of these organic compounds for the treatment of many ailments. Various chemical entities (functional groups) attached to the central moiety are responsible for their diverse range of biological properties. The development of the characterization of these plant metabolites and the enzymes involved in their biosynthesis is of an utmost priority to deliver enhanced advantages in terms of biological properties and productivity. Further, the incorporation of whole/partial metabolic pathways in the heterologous system and/or the overexpression of biosynthetic steps in homologous systems have both become alternative and lucrative methods over chemical synthesis in recent times. Moreover, in-depth research on alkaloid biosynthetic pathways has revealed numerous chemical modifications that occur during alkaloidal conversions. These chemical reactions involve glycosylation, acylation, reduction, oxidation, and methylation steps, and they are usually responsible for conferring the biological activities possessed by alkaloids. In this review, we aim to discuss the alkaloidal group of plant specialized metabolites and their brief classification covering major categories. We also emphasize the diversity in the basic structures of plant alkaloids arising through enzymatically catalyzed structural modifications in certain plant species, as well as their emerging diverse biological activities. The role of alkaloids in plant defense and their mechanisms of action are also briefly discussed. Moreover, the commercial utilization of plant alkaloids in the marketplace displaying various applications has been enumerated.

Potential of Seaweed Extract on Growth, Physiological, Cytological and Biochemical Parameters of Wheat (Triticum aestivum L.) Seedlings

“…To cope with environmental stress, plants have developed metabolic adaptability. In addition to their protective activities against biotic and abiotic stress, alkaloids serve as nitrogen reservoirs (Bhambhani et al 2021). According to Kasim et al (2016), the decrease in alkaloids as a result of seaweed priming could be ascribed to the seaweeds' potent antioxidant capacity, which protects the plant from the detrimental effects of ROS generated during cellular metabolism.…”

Effects of Light on Secondary Metabolite Biosynthesis in Medicinal Plants

“…Given their antitumor, antibacterial, and anti-inflammatory activities, alkaloids have been widely used for the production of medications (Jain et al, 2019;Zhang et al, 2021). Depending on their biosynthetic pathways and chemical structures, alkaloids are classified into five groups: terpene indole, benzylisoquinoline, tropine, purine, and pyrrolizidine alkaloids (Bhambhani et al, 2021). Figure 3A shows structures of some common bioactive alkaloids in medicinal plants, including three monoterpenoid indole alkaloids (MIAs; vindoline, vinblastine, and camptothecin), one benzylisoquinoline alkaloid (berberine), and two tropine alkaloids (hyoscyamine and scopolamine).…”

Antithrombotic and antiplatelet effects of plant-derived compounds: a great utility potential for primary, secondary, and tertiary care in the framework of 3P medicine

“…Alkaloids are naturally occurring nitrogen-containing plant metabolites [ 98 ]. Alkaloids are characterized by a great structural diversity that can be divided into 5 groups: true alkaloids, protoalkaloids, polyamine alkaloids, peptide and cyclopeptide alkaloids, and pseudoalkaloids [ 99 ].…”