8 New Geranylated Chalcones Isolated From Medicinal Plant Breadfruit; One Protects in a Brain Ischaemia Model

Researchers at the College of Pharmacy of Jinan University in China isolated eight new compounds of the geranylated chalcone class from the tropical medicinal plant breadfruit (Artocarpus communis) and named two of them, oligomers with complex ring structures, artocarpusone A and B. The paper was published in Angewandte Chemie International Edition.

From structure elucidation to "biomimetic synthesis"

Artocarpusones A and B have a pentacyclic hemiketal structure with fused 6/5/6/5/6 rings. The team determined the absolute stereochemistry by combining spectroscopic analysis and computational chemistry. In particular, they proposed a biosynthetic hypothesis that compounds 1 to 7 all derive from a single precursor (compound 8), designed a cascade of reactions running through oxidative rearrangement, Michael addition, hemiketalisation, electrocyclisation and a hetero-Diels-Alder reaction, and synthesised 1 to 7 from the precursor in just 7 to 9 steps. In effect, they made reproducible in the lab compounds that can be obtained from the plant only in trace amounts.

In bioactivity evaluation, compound 2 (artocarpusone B) showed activity in both cell experiments and animal experiments in ischaemic stroke models and was singled out as a neuroprotective candidate. Specific efficacy figures and the animal species and numbers were not given in the public abstract.

These are early results at the cell and animal level, so it is too soon to speak of effects or safety in people. It should also be noted that eating a plant extract is separate from the experimental results of a single purified compound.