Alkaloidal constituents of Crinum variabile and Crinum paludosum, two southern African Amaryllidaceae species

Date
2020-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: The extraction of dried bulbs of Crinum variabile and subsequent targeted fractionation led to the isolation of lycorine, 1,2-O,O-diacetyllycorine, 2-O-acetyllycorine, 1-O-acetyllycorine, a diastereomeric mixture of haemanthidine and 6-epihaemanthidine, bulbispermine and criwelline. HPLC-MS/MS analysis of the extract was carried out, providing information regarding other alkaloidal constituents of C. variabile. The isolation of lycorine, as well as a brief HPLC-MS/MS dereplication study was carried out on an extract of Crinum paludosum, allowing for the tentative identification of ten alkaloidal constituents therein, with five alkaloids remaining unidentified. A brief synthetic study was carried out on higginsianins A and B, resulting in the generation of some analogues thereof. These included acetylated analogues of both, as well as bromination products of higginsianin A, and reductive hydrogenation and epoxidation products of higginsianin B.
AFRIKAANSE OPSOMMING: Ekstraksie van gedroogde Crinum variabile blombolle en die daaropvolgende fraksionering het likorien, 1,2-di-O-asetiellikorien, 2-O-asetiellikorien, 1-O-asetiellikorien, ‘n mengsel van haemantidien en 6-epi-haemantidien, bulbespermien en kriwelien opgelewer. HPLC-MS/MS analise van die C. var. ekstrak het adisionele informasie van ander alkaloïde tot gevolge gehad. Isolasie van likorien asook ‘n kort HPLC-MS/MS analise van ‘n ekstrak van Crinum paludosum het tot gevolg gehad dat tien alkaloïde tentatief geidentifiseer kon word met nog vyf wat nie geidentifiseer kon word nie. ‘n Kort sintetise studie op higginsiansins A en B was uitgevoer en het gelei tot die isolasie van die geasetileerde higgginsiansins A en B, die gebromeerde analoog van higginsiansin A, die hidrogeneerde higginsiansin B en die epoksineringsproduk van higginsiansin B.
Description
Thesis (MSc)--Stellenbosch University, 2020.
Keywords
Amaryllidaceae, Alkaloids, Crinum, Crinum paludosum
Citation