TOTAL FLAVONOID CONTENT OF FALOAK (<em>STERCULIA QUADRIFIDA</em>) BARK IN VARIETIES OF BARK COLOUR, TREE DIAMETER AND GROWTH ALTITUDE

Abstract

Sterculia quadrifida (Sterculiaceae) grows in Indonesia, India, Timor Leste and Australia. In East Nusa Tenggara province, Indonesia, particularly in Timor Island, S. quadrifida is called ‘faloak’ and its bark is used to treat hepatitis. This study aims to determine the correlation between total flavonoid content and varieties of bark colour, tree diameter class and altitudes, and to examine the interaction between tree diameter class and altitudes in terms of flavonoid content. Sterculia quadrifida barks were collected from four altitude strata of ≤ 300, > 300–600, > 600–900 and > 900 m a.s.l. Each stratum of altitude consisted of three diameter classes of ≤ 15, > 15–30 and > 30 cm. Bark colour was classified using Munsell colour chart. The powdered barks were macerated with 96% ethanol and evaporated to yield thick extracts. The total flavonoid content of each extract was measured by spectrophotometry. There were four dominant colour groups, i.e., red, brown, yellow and orange. The highest total flavonoid content was found in the red (0.25%) and yellow (0.25%) barks. The results showed that the highest total flavonoid content was found in tree diameter of > 15–30 cm, with a total flavonoid of 0.22%. The highest total flavonoid content (0.21%) was observed in the barks from altitude range of ≤ 300 m a.s.l. There was a weak interaction between altitude and tree diameter on the extract yield and total flavonoid of S. quadrifida bark.