| dc.description.abstract | Oleanan derivative compound namely 3-acetyl-12-oleanen-28-oic acid, has been isolated
from n-hexane fraction of the bark M. umbellate (Houtt) Stapf var. degrabrata The
molecular structure was determined by IR spectroscopy, NMR 1D and 2D (1H-NMR, 13C NMR, DEPT, COSY, HMQC and HMBC). The results of test bioactivity to hexane,
chloroform, ethyl acetic, methanol extracts and compound 1 mentioned above showed
that they are toxic to A. salina (brine shrimp) with LC50 361.93 to 460 µg/mL. The most
toxic one was the compound 1 with the LC50 value of 361.93 µg/mL. At a concentration of
1000 µg/mL, the extract of hexane, methanol and compound 1 showed very high
inhibition to the growth of B. subtilis and C.albican, whereas the extract of ethyl acetate
had very high inhibition effect to the growth of S. aureus and A. niger. The inhibition zone
of the three extracts and compound 1 were greater than 14 mm. On the other hand, the
extracts of chloroform gave weak inhibition against bacteria and fungi. | en_US |
