International Journal of Marine Science, 2017, Vol.7, No.31, 297-307
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COSY spectrum (Figure 16) isolated compounds shown that there is a correlation between the protons at δH 2.34
ppm region deng protons in the region of 1.64 ppm. This spectrum also shows that the proton at δH 1.29 pp
regions correlated with the proton at δH 0.86 ppm region.
Based on the analysis of NMR data 1D and 2D NMR it is suspected that the isolated compounds are a group of
compounds, namely fatty acids oleic acid with the molecular formula C17H33COOH with a molecular weight of
282 g/mol with DBE as much as 1 piece. The structure of compound identification results are given in Figure 17.
Figure 16 COSY spectrum fragment area δH 0.8 ppm - 2.4 ppm δH
Figure 17 Oleic acid compound identification results
2.6 Measurement of antibacterial activity of crude extract
Antibacterial activity test using disc diffusion method using test bacteria
Escherichia coli, Shigella dysenteriae
,
and
Bacillus subtilis
which extracts tested antibacterial activity with three repetitions. The formation of a clear
zone is indicative of antibacterial activity.
The results of antibacterial activity test (Table 1) shows that the crude extract provides activities for the third test
bacteria
E. coli, S. dysenteriae
and
B. subtilis
. Criteria antibacterial power of inhibition zone diameter 1-9 mm
including categories weak inhibition, inhibition zone diameter of 10-14 mm category inhibitory medium and
inhibition zone diameter of 15-20 mm strong category (Davis and Stout, 1971). So based on these data it can be
concluded that the crude extract n-hexane H.gracillis not active antibacterial and ethyl acetate extract weak against
bacteria related B. subtilis and categories are against
E.coli and S.dysentreriae.
Table 1 Average data of test results crude extract antibacterial activity against
E. coli bacteria test, S.dysenteriae,
and
B. Subtillis
Sampel Ekstrak Kasar
Diameter Zona Bening (mm)
E. coli
S. dysenteriae
B.subtilis
n-heksan
0
0
0
Etil asetat
13,40
9,65
8,20
Kontrol (-)
0,0
0,0
0,0
The results of antibacterial activity test (Table 2) showed that the crude extract of H.
gracillis
showed clear zone
at a concentration of 200,000 ppm in weak category, while the concentration of 100,000 and 50,000 did not show
any antibacterial activity.
