Judul: Pengklasifikasian Propolis Lebah Madu Trigona spp. dari Empat Wilayah di Indonesia dengan Menggunakan Pendekatan Metabolomik Berbasis FTIR
Abstrak: Propolis is a resinous substance collected by honeybees from various plant sources. Propolis obviously possesses antioxidant activity, as reported by many researchers. Although numerous researchers have reported the biological activities of propolis collected worldwide, information about Indonesian propolis, particularly from Trigona spp., is only a few. Some studies reported that propolis has various bioactivities including antimicrobial, anticancer and antioxidant. These properties are influenced by phenols and flavonoids compounds.. The complex constituents and properties of propolis is different from each other depends on location and plant of origin. This variation will have an effect on its bioactivity. Indonesia has many local honey bees; one of them that produce propolis is Trigona spp. The location of propolis source used in this research may relate to its physical and chemical characteristics. Some researches have examined the correlation between phenol and flavonoid content with antioxidant activity of propolis. It was found that for some cases there is no correlation which implies that other compounds may have influence to the antioxidant activity. Therefore metabolomic is further used to observe this possibility. Metabolomic approach is capable of determination which regions have a potential propolis as a source of antioxidant. Metabolomic is defined as metabolite process analysis of the organism comprehensively quantitatively or qualitatively. Metabolomic approach in this study is focussed on classification of propolis as a result the difference of regions and its correlation to antioxidant activity. The objective of this research is to apply metabolomic in classification of propolis from four regions based on its FTIR metabolite profile and its antioxidant activity. Those four regions are West Nusa Tenggara, West Java, West Kalimantan and South Sulawesi. Since the composition of propolis varies with its origin, the intensity of antioxidant activity should be different as well. Metabolomic approach was used to identify which region has propolis with better antioxidant activity. FTIR based metabolomic was applied to measure the spectra of propolis in order to examine the differences among propolis samples then to classify them. For this purpose, the FTIR spectra were analyzed by PCA and PLS. In addition, the correlation between propolis phenol and flavonoid content to its antioxidant capacity was also determined. Interpretation of FTIR spectra showed the presence of O-H, C-O and C-H aromatic bond for phenol and its ester. Meanwhile, the presence of flavonoid compound is designated to C=O, C-H, C-H aromatic and supported by O-H bond. In addition, C=C, C-O bonds were also found which may relate to the presence of terpenes. The samples also confirm the presence of N-O symmetric, C-N and N-H which point to amino acid and aromatic amine. There were also C-O and O-H bonds which may relate to fatty acid. Nevertheless the existence of these compounds according to the functional groups is not confirmed yet. Then further confirmation by targeted analysis of propolis total phenol and flavonoid content and its correlation to propolis antioxidant activity are required. Antioxidant potential of propolis from four regions in Indonesia was accessed by analyze propolis scavenging effect on DPPH radicals which IC50 were in the range 0,54-2,90 μg/mL. Low values of IC50 on
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