Abstract
The Hyacinthaceae family (sensu APGII) is found in southern Africa, one of the major areas of growth and has approximately three hundred and sixty-eight species. It consists of four subfamilies, the Hyacinthoideae, Urgineoideae, Ornithogaloideae and Oziroeoideae. The Hyacinthoideae subfamily occurs mainly in southern Africa and is the largest out of the four sub-families, consisting of nearly two hundred regional members. The members of the Hyacinthoideae subfamily are recorded to be used as traditional medicines to treat hangovers, fractures, teething, syphilis and many other conditions by the southern African people. In this work, Pseudoprospero firmifolium (Baker) Speta subsp. natalensis, Resnova humifusa (Baker) U. & D. M. -D., Eucomis vandermerwei Verd., Eucomis zambesiaca Baker and Eucomis bicolor Baker were investigated for their chemical constituents. A total of forty-three compounds were isolated, of which fifteen compounds were novel. Pseudoprospero firmifolium yielded two homoisoflavonoids and a spirocyclic nortriterpenoid, Resnova humifusa yielded four homoisoflavonoids, one chalcone and a tetrahydropyran derivative, Eucomis vandermerwei yielded four homoisoflavonoids, Eucomis zambesiaca yielded five homoisoflavonoids and three spirocyclic nortriterpenoids and Eucomis bicolor yielded four homoisoflavonoids, six spirocyclic nortriterpenoids, a pentanortriterpenoid, a tetranortriterpenoid, a lanostane derivative and nine triterpenoid glycoside derivatives. The structures of these compounds were fully characterised using nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry, circular dichroism and optical rotational measurements. The homoisoflavonoid types of compounds are known for their anti-inflammatory activity. Therefore, the homoisoflavonoids that were isolated from this study were tested for their COX-2 inhibition. Also, most of the compounds isolated from this study were submitted to the National Cancer Institute (NCI) to be tested against 59 different human tumour cell lines.