Separation of secondary metabolites in DNA extraction process of Thymus and analysis of them by GC-mass

One of the basic needs of different techniques in molecule biology is the production of genomic DNA with desired quality and quantity. In some researches the plant samples are collected from nature and these plant tissues are usually adult and due to presence of carbohydrate، polyphenols complex and proteins in their components، we cannot extract DNA with high quality and quantity. In other hand، these complexes are bond with nucleic acids and separation of them from acid nucleic is difficult. In this study، genomic DAN extraction from the leaf of adult Thymus plant was carried out by Doyle and Doyle، Dellaporta، Kang and Yang and Khanuja methods. The results showed that Khanuja method with some modifications is better than others. In this extraction method، brown-sticky sediment was separated from DNA. Analysis by GC-Mass، IR and UV revealed that this sediment contain Thymol، Carvacrol، Nerolidol and Borneol. Thymol substance has the greatest amount in GC (%65). So، the improved Khanuja method can separate the main secondary metabolites of Thymus and this method could be advised for DNA extraction from adult and mature plant.