الفهرس 
Using RAPD to detect genetic variability and total phenolic compounds among Coleus blumei varietiesOnly 14 pages are availabe for public view
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Abstract
Members of the Lamiaceae family of plants are noted for their accumulation of rosmarinic acid (RA), caffeic acid ester and 3,4-dihydroxyphenyllactic acid.
The biosynthesis of this natural product has been thoroughly elucidated in Coleus blumei (Lamiaceae) suspension cultures. (Petersen 1993, Petersen 1997).
The biosynthetic precursors are two amino acids tyrosine and phenylalanine
(Ellis1970.) Phenylalanine is changed to 4-coumaroyl/Co enz A by the enzymes of
the phenylpropanoid path, where tyrosine is transformed to 4-hydroxyphenylpyruvic
acid via transamination catalyzed by the enzyme tyrosine aminotransferase (De
Eknamkul and Ellis1987). pHPP is reducted to 4-hydroxy phenyl lactic acid (pHPL) by hydroxy phenyl pyruvate reductase (HPPR, EC 1.1.1.237) (Petersen and Alfermann 1988, Ha¨usler and Petersen1991) and pHPLesterified with 4-coumaric acid from 4-coumaroyl_/CoA by RA synthase [M. Petersen, E. 1993, M.S.
Petersen1991] followed by cytochrome P450- dependent hydroxylation in positions 3 and 3 of the ester thus resulting in RA (Petersen 1997).
Coleus has been popular in traditional medicines because of its curative properties, due to the presence of complex secondary plant metabolites in one or more parts of these plants. Coleus finds application in the treatment of eczema and psoriasis. It is
also used as anticancer, antidepressant, antidiuretic, bronchodilator, cardiotonic, gastrostimulant, gluconeogenic, immunosuppressant, lipolytic, myorelaxant, neurogenic, thyrotropic and vasodilator. In the present era, herbal medicine is gaining
much popularity over the synthetic drugs considering the safety aspect. However, if accurate and rapid authentication of plants used in traditional medicine is not achieved it can prove to be potentially toxic and mutagenic. It is here that Random 6Amplified Polymorphic DNA (RAPD) markers can be used effectively to identify the authenticity of Coleus.
The synthesis of the aromatic amino acids tyrosine and phenylalanine in plants leads from chorismate via prephenate and arogenate to tyrosine and phenylalanine [E. Haslam1993], therefore, pHPP is no transitional of aromatic amino acid synthesis
in higher plants. On the other hand, pHPP is not only a precursor for RA but was thought to be essential for the formation of the prenylquinones plastoquinones and tocopherols, essential components of plastids of higher plants helping as
photosynthetic electron carriers, antioxidants and singlet- oxygen scavengers (Douce and Joyard1996).