الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
The aim of the present study is to investigate the phytochemicals nature of
Globularia arabica (Gloulariaceae) and their antimicrobial activity against some
pathogenic bacteria. The arial parts of G. arabica were collected from Al-Halal
Mountain, Sinai, Egypt. The chromatographic technique normal-phase-silica-gelcolumn was used to isolate the iridoid glycosides which elucidated by spectroscopic
analysis. The results showed that G. arabica fractions:15, 20, 50 and 75% MeOH:
DCM contains iridoid glycosides. Isolation of these fractions gives six different
compounds which are: Piscroside B (71), Jatamanvaltrate type (72), Angelosid (73),
8-O-(p- Coumaroyl)-harpagide (74), p- hydroxy globularinin (75) and 6-O-(pcoumaroyl) ajugol (76). The antimicrobial activity of G. arabica (crude extract and
their fractions) against the Gram-negative (Klebsiella SPP, Klebsiella MDR) and
Gram-positve (Staphylococcus aureus) bacteria was evaluated. Although the crude
extract was inactive against the tested bacteria, fraction 20 % MeOH: DCM and some
of their isolated compounds were more sensitive at a concentration of 500 mg/ml.
The present results ascertained the role of the experimental techniques of natural
products isolation in drug discovery protocol. Further photochemical and biological
screening will be applied on the other fractions of G. arabica extract and the isolated
compounds. The present study covered the following points: