Abstract:
Flavonoids are a class of plant secondary metabolites. Flavonoids were referred to as Vitamin
P from the mid-1930s to early 50s, but the term has since fallen out of use. Since D. metel is as
rejuvenating herb this study was planned to estimate the flavonoid content in D. metel because
flavonoids also determine the antioxidant capacity of the plant. The plant was obtained from
Government herbal garden, Navakkiri, Puththur, Jaffna and taxonomically authenticated. The
collected plants were washed thoroughly in running tap water and it was separated into leaf,
flower, stem, and root immediately. Then they were dried in sun shade and were powdered.
Then powders were stored in air tight dry labeled plastic containers. Cold and hot water extract
were prepared form the powders.
The concentration of flavonoids in various plant part extracts of the D. metel was determined
by aluminum chloride method using spectrophotometry and the flavonoid content expressed as
mg of tannic acid equivalent/ gm of DW. The assay was performed in duplicates and data
presented as mean ± SD. One percent tannic acid used as standard. The concentration of
flavonoids in cold and hot water extracts of different parts ranged from 358 ± 23.38 to 495.68
± 43.63 μmol/g DW and from 444.70 ± 43.63 to 562.50 ± 71.97 μmol/g DW respectively. Both
cold and hot water extracts of flower had the highest flavonoid concentration 495.68 ± 75.73,
562.5 ± 71.97 μmol/g DW respectively. The lowest flavonoid concentration was found in the
root. According to the study both cold and hot water extract of flower were showed highest
amount of flavonoid content.
