I= PHYTOCHEMICAL AND STRUCTURAL STUDIES ON THE CHEMICAL CONSTITUTENTS OF BUXUS HILDEBRANDTII AND B. SEMPERVIRENS
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Title of Thesis
PHYTOCHEMICAL AND STRUCTURAL STUDIES ON THE CHEMICAL CONSTITUTENTS OF BUXUS HILDEBRANDTII AND B. SEMPERVIRENS

Author(s)
Athar Ata
Institute/University/Department Details
University of Karachi/ H.E.J. Research Institute of Chemistry
Session
1995
Subject
Chemistry
Number of Pages
263
Keywords (Extracted from title, table of contents and abstract of thesis)
buxus hildebrandtii, b. sempervirens, steroidal alkaloids, buxus alkaloids, buxus sempervirens

Abstract
This dissertation describes the phytochemical investigations on the two medicinally important plant, namely Buxus hildebrandtii of Ethiopian origin and B. Sempervirens of Turkish origin. Phytochemical investigations on the leaves of B. hildebrandtii have yielded four new steroidal alkaloids (+)-02-buxafuranamine (75), (+)-6-hydroxy-02–buxafuranamine (76), ( - ) 010 –buxafuranamine (77) and (-)-6-dehydroxy-010 –buxafuranamine (78), along with the known steroidal alkaloids. (+)-irehine (79), (+)-cyclovirobuxine-D (80), (-)cyclosuffro-buxinine-M (81). (-)-E-Buxenone (82) and (-)-Z-buxenone (83), (+)-16a-acetoxybuxabenzamidienine (84) and (+)-benzoylbuxidienine (85), isolated for the first time from the leaves of B. hildebrandtii.

Chemical studies on the roots of Buxus sempervirens have yielded seven new steroidal alkaloids, (+)-16a,31-diacetylbuxadine (86), (+)-semperviraminol (87), (+)-papillotrienine (88), (+)-Nb-demethylpapillo-trienine (89), (+)-buxamine-F (90), (+)-buxaminol-C (91) and (+)-17-oxocycloprotobuxine (92), along with the known steroidal alkaloids, (+)-papilamine (93), (-)-cyclobuxophylline-K (94), (+)-buxaquamarine (95), (+)-buxoxybenzamine (96) and (+)-buxapapilinine (97).Compounds 86, 87, 90, 96 and 97 have shown anti-bacterial and anti-fungal activities, while compounds 86,96 and 97 have also shown phytotoxic activity. Structures of these new and known steroidal alkaloids were established on the basis of extensive spectroscopic studies including one and two-dimensional, and inverse two-dimensional (HMQC and HMBC) NMR experiments.

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
93.45 KB
2 1 Introduction 1
18.64 KB
3 2 Steroidal Alkaloids 3
264.49 KB
  2.1 Pharmacology of Buxus Alkaloids 27
4 3 Biosynthesis of Buxus Alkaloids 30
119.22 KB
5 4 Phytochemical Studies on the Leaves of Buxus hildebrandtii 43
718.08 KB
  4.1 Results and Discussion 43
  4.2 Experimental 111
6 5 Phytochemical Investigations on the Roots of Buxus sempervirens 128
933.41 KB
  5.1 Results and Discussion 128
  5.2 Experimental 218
7 6 References 238
235.56 KB