Securinega Alkaloids: Synthesis and Biological Activity

Securinega alkaloids form a distinctive class of plant-derived indolizidine and securinane natural products characterised by a tetracyclic framework bearing a γ-lactone ring fused to a piperidine core. Originally isolated from species such as Flueggea virosa and Phyllanthus glaucus, these compounds display a broad spectrum of biological activities, including anticancer, neuroprotective and antiparasitic effects. Synthetic chemists have long pursued efficient routes to construct the bridged heterocycle and to introduce oxidative diversity at late stages, thereby enabling access to both basic and highly oxidised analogues. Recent advances in total synthesis, molecular editing and computational modelling have deepened understanding of structure–activity relationships, illuminated molecular targets such as microtubules and differentiation pathways, and paved the way for the rational design of securinega-based therapeutics.

Research from Nature Portfolio

A recent study established a unified stereocontrolled platform for the total synthesis of C4-oxygenated securinine-type alkaloids. By integrating selective oxidation, skeletal rearrangement and epimerisation at strategic centres on the piperidine core, the work achieved the synthesis of securingines A, C and D, securitinine, secu’amamine D, phyllanthine and 4-epi-phyllanthine. This approach overcomes longstanding challenges in forging high-oxidation state motifs and provides a versatile foundation for rapid analogue generation and further chemical diversification of the securinega family.

Securinega Alkaloids: Synthesis and Biological Activity publication trend

The graph below shows the total number of articles in securinega alkaloids: synthesis and biological activity across all publications each year (not limited to Nature Index journals).

Technical terms

Indolizidine alkaloid: Nitrogen-containing heterocyclic natural product characterised by a fused bicyclic indolizidine skeleton.

Securinane: Subfamily of securinega alkaloids featuring a piperidine-based core structure.

Norsecurinane: Alkaloid subclass possessing a pyrrolidine core, derived via single-atom deletion from securinine.

Piperidine core: Six-membered saturated heterocycle containing one nitrogen atom, central to securinane frameworks.

Butenolide (γ-lactone): Unsaturated five-membered lactone ring common in securinega alkaloids.

Epimerisation: Process of inverting the stereochemistry at a specific chiral centre.

Molecular docking: Computational technique to predict the preferred orientation and binding affinity of a small molecule to a protein target.

Pironetin site: Specific binding pocket on α-tubulin originally identified for attachment of the natural product pironetin.

References

1. Interaction of Norsecurinine-Type Oligomeric Alkaloids with α-Tubulin: A Molecular Docking Study. Plants (2024).
2. Securinine, a Myeloid Differentiation Agent with Therapeutic Potential for AML. PLOS ONE (2011).
3. Securinine from Phyllanthus glaucus Induces Cell Cycle Arrest and Apoptosis in Human Cervical Cancer HeLa Cells. PLOS ONE (2016).
4. Collective total synthesis of C4-oxygenated securinine-type alkaloids via stereocontrolled diversifications on the piperidine core. Nature Communications (2022).
5. Chemical Constituents from Flueggea virosa and the Structural Revision of Dehydrochebulic Acid Trimethyl Ester. Molecules (2016).
6. Unique indolizidine alkaloid securinine is a promising scaffold for the development of neuroprotective and antitumor drugs. RSC Advances (2021).
7. Transformation of (allo)securinine to (allo)norsecurinine via a molecular editing strategy. Frontiers in Chemistry (2024).