Medicinal plants containing pyrrolizidine alkaloids in the New Kreuterbuch by Leonhart Fuchs (1543).

In mid-16 th century, three scientific books have been edited, which have been a real sensation, each one in its own scientific field. The first one, published in Nürnberg by Nikolaus Kopernikus, named: "De Revolutionibus Orbium Celestium Libri VI" put the sun in the center of the universe, and takes the human being out of the middle of the world. The second one, published in Basel by Andreas Vesalius: "De Humani Corporis Fabrica", describes the anatomy of the human body and the third one, also published in Basel by Leonhart Fuchs, was named "New Kreuterbuch". It shows woodcuts of the most important medicinal plants of its time along with botanical descriptions and therapeutic uses. This book emerged as one of the most influential botanical works of the 16 th century and is still interesting. Here, we used it to investigate which medicinal plants of the Early Modern times contained pyrrolizidine alkaloids. In total, 15 species were identified.

The History of the Glycosidase Inhibiting Hyacinthacine C-type Alkaloids: From Discovery to Synthesis.

BACKGROUND: The inherent glycosidase inhibitory activity and potentially therapeutic value of the polyhydroxylated pyrrolizidine alkaloids containing a hydroxymethyl substituent at the C-3 position have been well documented. Belonging to this class, the naturally occurring hyacinthacine C-type alkaloids are of general interest among iminosugar researchers. Their selective micromolar α -glycosidase inhibitory ranges (10 - 100 µM) suggest that these azasugars are potential leads for treating type II diabetes. However, the structures of hyacinthacine C1, C3 and C4 are insecure with hyacinthacine C5 being recently corrected. OBJECTIVE: This review presents the hyacinthacine C-type alkaloids: their first discovery to the most recent advancements on the structures, biological activities and total synthesis. CONCLUSION: The hyacinthacine C-type alkaloids are of exponentially increasing interest and will undoubtedly continue to be reported as synthetic targets. They represent a challenging but rewarding synthetic feat for the community of those interested in accessing biologically active iminosugars. Since 2009, ten total syntheses have been employed towards accessing similarly related products but only three have assessed the glycosidase inhibitory activity of the final products. This suggests the need for an accessible and universal glycosidase inhibitory assay so to accurately determine the structure-activity relationship of how the hyacinthacine C-type alkaloids inhibit specific glycosidases. Confirming the correct structures of the hyacinthacine C-type alkaloids as well as accessing various analogues continues to strengthen the foundation towards a marketable treatment for type II diabetes and other glycosidase related illnesses.