Abstract
Historically, plants (fruits, vegetables, medicinal herbs) have provided a good source of a wide variety of compounds, such as phenolic compounds, nitrogen containing compounds, vitamins, terpenoids and some other secondary metabolites, which are rich in valuable bioactivities e.g. antioxidant, anti-inflammatory, larvicidal, anti-mutagenic, anti-carcinogenic, anti-malarial, antibacterial or anti-viral activities. Recently artemesinin from the Chinese herb Artemisia annua has been formulated into drugs for antimalarial activity. In many countries, the traditional herbal medicine has been widely used for thousands of years. Herbal plants have become the main object of chemists, biochemists and pharmacists. Their research has played an important role for discovering and developing new drugs. Natural products from plants have been used for centuries to prevent or cure diseases, those plant extracts from the family Phyllanthaceae, Euphorbiaceae and Meliaceae have been used traditionally for the treatment of diseases such as kidney disorders, urinary bladder infections, intestinal infections, jaundice, gonorrhea, diabetes (internal use) as well as poultices, skin ulcer and other skin problems (external use). Infusions have been made from young shoots as a treatment of chronic dysentery. Many plant extracts have been evaluated for their biological activities. However, most of the plants from the families have not been investigated before for their chemical composition, therefore the rationale of this study. The study sought to identify, extract, isolate, purify and characterize compounds from the following plants: Phyllanthus cedrelifolius and Phyllanthus reticulatus of the Phyllanthaceae family, Sapium integerrimum of the Euphorbiaceae and Malleastrum rakotozfayi of the Meliaceae family. By use of various isolation and purification techniques, a total of twenty-six compounds were isolated from the four plants, of which nine were unreported previously. The compounds belonged to four main classes: Triterpenoids, diterpenoids, coumarin types and a tocopherol. ID and 2D NMR, IR, MS, optical rotation and melting points were used in determining the structures of the compounds.