Phytochemical Studies of Some Bangladeshi Plants

Organic chemistry, Botany

Haque, Md. Enamul

University:University of Glasgow

关键词: Organic chemistry, Botany;   

Others  :  http://theses.gla.ac.uk/75829/1/13818565.pdf

来源: University of Glasgow

【 摘 要 】

Chapter 1 consists of a general description of the plant families Annonaceae, Piperaceae, Meliaceae, Rubiaceae and Euphorbiaceae, in particular in terms of their main secondary metabolites and their biological activity. Chapter 2 presents a brief account of the biosynthetic pathways leading to the alkaloids, flavonoids and triterpenoids described in later chapters. Chapter 3 describes the isolation of three novel methylated flavonoids from the bark of Desmos longiflorus (Annonaceae). The structures were determined largely by use of HMQC, HMBC and NOE difference techniques. Two other new compounds, a lanostane and a protoberberine alkaloid, were also obtained from the extract together with several known aporphine alkaloids, steroids, benzyl benzoate and the cyclohexane derivative, crotepoxide. Chapter 4 concerns the structural elucidation, by 2D NMR methods, of a new 2-oxo-11beta,16-epoxy-16-epicafestol derivative from Cojfea bengalensis (Rubiaceae). Chapter 5 discusses the isolation of several isoquinoline alkaloids and the known sesquiterpenoid spathulenol from the Annonnaceous species Artabotrys odoratissimus. Chapter 6 describes the isolation and characterisation of two new and one known bisdehydroaporphine alkaloids from the bark extract and a known aporphine alkaloidfrom the leaf extract of Polyalthia bullata (Abetannonaceae) which is valued in Malaysia as an aphrodisiac (tonquat ali). Chapter 7 gives an account of the isolation of the cyclohexene derivative zeylenol and two new pseudosugars from another Annonaceae, Annona roxburghiana. In Chapter 8 the isolation of the known compounds, lupeol, lupeone, scopoletin and betulin 3 caffeate from Antidesma ghaesembilla (Euphorbiaceae) is discussed. In Chapter 9 the isolation of one new and six known dammarane triterpenoids and the sesquiterpenoid viridiflorol from Amoora cucullata (Meliaceae) is discussed. The final Chapter 10 gives an account of an investigation of Piper chaba (Piperaceae) which produced piperanine, 2,4-decadienoic acid piperidide, pellitorine and the lignan (-)-kusunokinin.