Biosynthesis and biomimetic synthesis of alkaloids isolated from plants of the Nitraria and Myrioneuron genera: an unusual lysine-based metabolism

Abstract

This review describes a wide panel of alkaloids isolated from plants of the Nitraria genus, focusing on their biosynthesis and discussing the resulting biomimetic chemistry in relevant cases. The scope is purposely limited to alkaloids derived at least to some extent from L-lysine, considering that most of these molecules have unique structures and are specific to the genus. Some of the biosynthetic pathways described are taken from the literature, but others are proposed here for the first time. The latter are mostly hypotheses justified by the fact that they are based on metabolic routes frequently encountered for other Nitraria alkaloids, and thus permit unification of the biosynthesis around common pivotal biosynthetic intermediates. Myrioneuron alkaloids are also presented as a newly discovered class with striking similarities to Nitraria alkaloids.

Manipulating Simple Reactive Chemical Units: Fishing for Alkaloids from Complex Mixtures

“…The exact role of enzymatic control in such biosynthetic pathways is thereby an interesting question that can be addressed through biomimetic synthesis as detailed in the following sections. Myrioneuron alkaloids, which include structures such as 15 and myrioneurinol ( 17 ), share some common features with Nitraria metabolism and will be discussed separately (see the Perspectives section) 5…”

“…There are many ways by which reactive C 5 units can produce interesting molecular skeletons, but the most straightforward one certainly is self‐condensation. While carrying out studies towards the biomimetic synthesis of Nitraria alkaloids5 we witnessed the formation of original structures derived from the self‐condensation of tetrahydropyridine ( 4 ) or glutaraldehyde ( 10 ) derivatives.…”

“…Nitraramine ( 14 ) is a small but complex cage‐like structure, isolated from Nitraria schoberi in the 1980s 5. Its formation in the plant can be explained by a reaction sequence mainly consisting of imine/enamine tautomerism, Michael/retro‐Michael, Mannich/retro‐Mannich, and hydrations/dehydrations 14.…”

Biomimetic Synthesis of Ornithine/Arginine and Lysine‐Derived Alkaloids: Selected Examples

“…In 2010, one of us published a comprehensive review covering the state of knowledge and detailing the isolation, structure determination (and revision), and the biomimetic syntheses of Nitraria alkaloids [87]; the interested reader is directed to this article as well as to older reviews [86]. Many achievements in biomimetic synthesis of Nitraria alkaloids have been disclosed by the Koomen group [88] and the Husson group [89].…”

L-Leucine Templated Biomimetic Assembly of SnO2 Nanoparticles and Their Lithium Storage Properties

“…Biomimetic synthesis is a novel route to fabricate nanosized inorganic particles with organic templates. Investigations have identified that specific molecular interactions at inorganic-organic interfaces could result in the controlled nucleation and growth of inorganic crystals [24–26]. During the biomimetic assembly process, the organic template could promote self-assembly, recognize the reactant substrate, guide the nucleation, and limit the growth of inorganic particles by utilizing biological adsorption, hydrogen bond, van der Waals force, and so on.…”