Amabiloid A from Crinum × amabile Donn ex Ker Gawl

Isolation and structure elucidation of antioxidant compounds from stem and root barks of Daphne giraldii

Two new compounds, aphegiractin A1/A2 (1a/1b), and seven known compounds were isolated by phytochemical work on EtOAc-soluble ingredients extracted from stem and root barks of Daphne giraldii. Their structures were established based on extensive spectroscopic methods, including HRESIMS, CD experiments, 1D and 2D NMR. All compounds were evaluated for their antioxidant activity to DPPH, ABTS radical scavenging activity and inhibitory activity on tyrosinase. Of these compounds, compound 3 exhibited significant antioxidant activities.

Alkaloids with cholinesterase inhibitory activities from the bulbs of Crinum × amabile Donn ex Ker Gawl

Seven previously undescribed alkaloids, crinamabilines A-G, two non-alkaloidal compounds, crinamabidiene and 6-phenylpiperonyl alcohol, two first naturally occurring alkaloids, 3-epibuphanisine and (+)-1β,2β-epoxy-epicrinine, together with nineteen known alkaloids, were isolated from the bulbs of Crinum × amabile Donn ex Ker Gawl. Their structures and absolute configurations were elucidated by NMR, MS and ECD spectroscopic techniques. Ungeremine displayed the most potent inhibitory activity against acetylcholinesterase (IC₅₀ 0.21 μM), which was about 6-fold more active than the reference drug, galanthamine (IC₅₀ 1.23 μM). Ungeremine also exhibited the strongest inhibitory activity against butyrylcholinesterase (IC₅₀ 3.57 μM), which was comparable to galanthamine (IC₅₀ 3.11 μM). The molecular docking studies were performed and were well in agreement with the experimental results.

The Phytochemistry and Pharmacology of Tulbaghia, Allium, Crinum and Cyrtanthus: ‘Talented’ Taxa from the Amaryllidaceae

Amaryllidaceae is a significant source of bioactive phytochemicals with a strong propensity to develop new drugs. The genera Allium, Tulbaghia, Cyrtanthus and Crinum biosynthesize novel alkaloids and other phytochemicals with traditional and pharmacological uses. Amaryllidaceae biomolecules exhibit multiple pharmacological activities such as antioxidant, antimicrobial, and immunomodulatory effects. Traditionally, natural products from Amaryllidaceae are utilized to treat non-communicable and infectious human diseases. Galanthamine, a drug from this family, is clinically relevant in treating the neurocognitive disorder, Alzheimer’s disease, which underscores the importance of the Amaryllidaceae alkaloids. Although Amaryllidaceae provide a plethora of biologically active compounds, there is tardiness in their development into clinically pliable medicines. Other genera, including Cyrtanthus and Tulbaghia, have received little attention as potential sources of promising drug candidates. Given the reciprocal relationship of the increasing burden of human diseases and limited availability of medicinal therapies, more rapid drug discovery and development are desirable. To expedite clinically relevant drug development, we present here evidence on bioactive compounds from the genera Allium, Tulgbaghia, Cyrtanthus and Crinum and describe their traditional and pharmacological applications.