Browsing by Author "Moodley, Nivan."

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The chemical investigation of Ledebouria zebrina and Scilla natalensis.
(2001) Moodley, Nivan.; Crouch, Neil Robert.; Mulholland, Dulcie Aca.
Ledebouria zebrina and Scilla natalensis Planch were the two species investigated in this work. Ledebouria zebrina belongs to the Hyacinthaceae (Liliacea sensu lato) and to this date, the chemical composition of this species has not been investigated. Members of this family are found in southern Africa. The Ledebouria genus was formerly classified as part of the Scilla genus from which a large member of naturally occuring oxygen heterocycles known as homoisoflavanones have been isolated. In this work the bulbs of L. zebrina were investigated and five compounds were isolated. Three compounds were of the homoisoflavanone type while the remaining two belong to the eucosterol type triterpernoids. Scilla natalensis Planch also belongs to the Hyacinthaceae family. Previous chemical investigations of the bulbs of this plant yield two homoisoflavanones of the 3-benzyl-4- chromanone type. Members of this family are mostly found in the Eastern parts of the country, ranging from the Eastern Cape to Mpumalanga province including Lesotho and Swaziland. The bulbs of this plant were investigated and this yielded ten compounds. The structures of the isolated compounds were elucidated using spectroscopic methods.
The chemical investigation of the Amaryllidaceae and Hyacinthaceae.
(2004) Moodley, Nivan.; Mulholland, Dulcie Aca.; Crouch, Neil Robert.
This work is an account of investigations into the chemistry of members of the Amaryllidaceae and Hyacinthaceae families. The plants of the family Amaryllidaceae are a large group comprising over sixty genera and more than a thousand species. They are widely distributed, but are found more richly in the tropics, with a particularly high density in South Africa, with smaller centers of diversity in Andean South America and the Mediterranean. Amaryllidaceae plants have been extensively used by local traditional healers and have been reported to have numerous pharmacological uses. The alkaloids isolated from this family are a group of isoquinoline alkaloids found exclusively in this family. Plants belonging to two Amaryllidaceae genera were investigated phytochemically, one from each of the sub-tribes Crinineae and Amaryllidineae were investigated phytochemically. Brunsvigia natalensis is used in local traditional medicine to "straighten bones of children", treat barrenness in women and ease childbirth. This is the first phytochemical investigation of Brunsvigia natalensis, and yielded two new alkaloids, a new ceramide type compound and a known flavanoid. A comparative phytochemical investigation was carried out on the bulbs and seeds of Crinum stuhlmanni, which resulted in a number of different alkaloids being isolated from the seeds and bulbs of this plant. The southern African Hyacinthaceae is a large and chemically morphologically diverse group of plants. This family comprises approximately sixty-seven genera and nine hundred species worldwide, of which twenty-seven genera and three hundred and sixty - eight species are found locally. There are five sub-families of which three occur in southern Africa. The chemical constituents of this family can be divided into four classes, namely homoisoflavanones, steroidal compounds, bufadienolides and miscellaneous compounds. These plants are used in local traditional medicine for treating ailments such as hangovers, rheumatic fever, sprains and even cancer. The phytochemistry of three Hyacinthaceae plants was studied. The phytochemical investigation of Drimia macrocentra and Urginea riparia yielded a novel bufadienolide glycoside. These glycosides are quite unusual with the glycone attached to the aglycone at C-2 and C-3 and this has only been reported only once before in this family. The phytochemical investigation of Ledebouria revoluta yielded a number of homoisoflavanones. These homoisoflavanones have been shown to have anti-inflammatory activity and all of the compounds isolated in this work have been screened for this activity. Structural elucidation was carried out using spectroscopic methods such as NMR, MS, UV and IR.