Abstract:
Plumeria Rubra L is one of the ornamental plants of the Apocynaceae family which has
been empirically proven as a medicinal plant. This study aimed to isolate and
characterize secondary metabolites from an n-hexane extract of red frangipani flowers
and to test the toxicity of n-hexane extract from red frangipani flowers using the Brine
Shrimp Lethality Test (BSLT) method. The sample was macerated using methanol as
solvent, then partitioned with n-hexane and ethyl acetate as solvent. Isolation of
secondary metabolites of n-hexane extract was carried out using Vacum Liquid
Chromatography (VLC) into seven separation fractions. The results of fraction four (4)
and fraction five (5) respectively produced the dirty compounds PRL-H-4 and PRL-H-
5. Purification by recrystallization is carried out on each compound, then the pure
compound produced will be tested for its melting point and characterized using FT-IR
and UV-Vis. The PRL-H-4 compound has a melting point of 248-250ºC with FT-IR
results showing absorption at a wave number of 3276 cm-1 which indicates the (OH)
group, 2944-2854 cm-1 C-H aliphatic (alkane), 1683 cm-1 (C=C alkene), 1457.28 cm-1
(CH2), 1042 cm-1, and 1036 cm-1 bonds (C-O), in the UV-Vis, results from there is a
maximum absorption at a wavelength of 207 nm. The PRL-H-5 compound has a
melting point of 130-132ºC with FT-IR results showing absorption at a wave number of
3428-3298 cm-1 which indicates the (OH) group, 2937 cm-1 C-H aliphatic (alkane),
1669 cm-1 (C=C alkene), 1465 cm-1 (CH2), 1382 cm-1 (CH3), 1054 cm-1 bonds
(C-O), in the UV-Vis, results from there is a maximum absorption at a wavelength of
203 nm. Based on the characterization results, PRL-H-4 is a triterpenoid compound, and
PRL-H-5 is a steroid compound. The results of the toxicity test using the Brine Shrimp
Lethality Test (BSLT) method showed that the n-hexane extract was non-toxic with an
LC50 value of > 1000 ppm.
