Alkaloid Constituents of the Amaryllidaceae Plant Amaryllis belladonna L

Abstract

The plant family Amaryllidaceae is well-known for its unique alkaloid constituents, which exhibit a wide range of biological activities. Its representative, Amaryllis belladonna, has a geographical distribution covering mainly southern Africa, where it has significant usage in the traditional medicine of the native people. In this study, A. belladonna samples collected in Brazil were examined for alkaloid content. Alkaloid profiles of A. belladonna bulbs were generated by a combination of chromatographic, spectroscopic and spectrometric methods, including GC–MS and 2D NMR. In vitro screening against four different parasitic protozoa (Trypanosoma cruzi, T. brucei rhodesiense, Leishmania donovani and Plasmodium falciparum) was carried out using the A. belladonna crude methanol extract, as well as three of its alkaloid isolates. Twenty-six different Amaryllidaceae alkaloids were identified in the A. belladonna bulb samples, and three of them were isolated. Evidence for their respective biosynthetic pathways was afforded via their mass-spectral fragmentation data. Improved data for 1-O-acetylcaranine was provided by 2D NMR experiments, together with new 1H-NMR data for buphanamine. The crude extract and 3-O-acetylhamayne exhibited good antiprotozoal activity in vitro, although both with a high cytotoxic index.

Hippeastrum reticulatum (Amaryllidaceae): Alkaloid Profiling, Biological Activities and Molecular Docking

“…The HRMS data of compounds 3 and 4 suggested the molecular formula C 17 H 22 NO 4 for the parent ion [M + H] + at m/z 334.1651 (calcd 334.1649). The 1 H-NMR data summarized in Table 3 were similar to those reported for zephyranthine, 1,2- O -diacetylzephyranthine [ 28 ] and sternbergine [ 29 ] and 1 -O -acetylcaranine [ 30 ] ( Figure 2 ). A correlation between the protons of the methoxy group and H-10 in the 2D NOESY spectrum allowed us to assign this group at C-9 in both compounds ( Figure 4 ).…”

Cholinesterase Inhibition Activity, Alkaloid Profiling and Molecular Docking of Chilean Rhodophiala (Amaryllidaceae)

“…Amaryllidaceae alkaloids occurring in the samples were identified by comparison of the Rt, fragmentation patterns and data interpretation of the spectra. The database used was built using single alkaloids previously isolated and identified by spectroscopic and spectrometric methods (NMR, UV, CD, IR, MS) in the Natural Products Laboratory, Universidad de Barcelona, the NIST 05 Database and literature data [ 37 , 38 , 39 , 40 , 41 , 42 ].…”

Amaryllidaceae alkaloids with anti-Trypanosoma cruzi activity

“…Alkaloid constituents found in these plants are classified in eight groups based on structure and biogenesis from the common precursor O-methylnorbelladine: galanthamine; lycorine; crinine; haemanthamine; homolycorine; narciclasine; tazettine; and montanine [14]. The unique structure of this set of alkaloids provides a viable platform for phytochemical-based drug discovery [8].…”