Mekanisme dan Kinetika Quenching Oksigen Singlet dari Senyawa Fenolik Daun Cengkeh Terhadap Fotoksidasi yang Disensitasi oleh Eritrosin

https://doi.org/10.22146/agritech.9620

Edi Suryanto(1*), Johnly A Rorong(2), Dewa Gede Katja(3)

(1) Jurusan Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Sam Ratulangi, Kampus Unsrat, Bahu Manado 95115
(2) Jurusan Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Sam Ratulangi, Kampus Unsrat, Bahu Manado 95115
(3) Jurusan Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Sam Ratulangi, Kampus Unsrat, Bahu Manado 95115
(*) Corresponding Author

Abstract



The objectives of this research were to isolate phenolic compound of clove leaves and to study the mechanism and kinetic of singlet oxygen quenching. Clove leaves was extracted by steam distillation using water for 6 hours. Crude clove leaves oil was purifi ed by distillation under reduced pressure. Isolated fractions were determined its structure by infrared (IR), nuclear magnetic resonance (1H-NMR), and mass spectrometry (MS) techniques. The effects of 0, 500, 1000 and 1500 ppm isolated compound on the photooxidation of linoleic acid (0,03M) containing 15 ppm erythrosine in ethanol were studied by measuring peroxide value of the oil. The quenching mechanism and kinetics of eugenol were studied by the steady-state kinetic method. Samples of 0; 0,06 x 10-4; 0,12 x 10-4; 0,24 x 10-4 dan 0,48x 10-4 mM eugenol prepared in water contained 0; 17,05 x10-4; 34,10 x 10-4; 68,19 x 10-4 and 136,39 x 10-4 mM of erythrosine stored under fl uorescent light (4000 lux) at room temperature for 15 hours. The result indicated that eugenol content of clove oil, F1, F2, F3 and F4 were 49.68; 54.32; 87.16 and 73.65%, respectively. The structure of F3 was identifi ed by IR spectrometry which shows strong absorption at 3448 cm-1 indicating hydroxyl group from the phenolic compound and the 1H NMR spectra showed that the number of proton ring was 3 hydrogen while the mass spectrometry showed the molecular ion peak at m/e = 164 as base peak and the absence of peak at (M-41)+ as the indicator of eugenol. The result showed that eugenol had antiphotooxidation activity on erythrosine sensitized photooxidation of oil. The mechanism of singlet oxygen quenching on erythrosine photodegradation showed that eugenol only quenched singlet oxygen. The total quenching rate constant of eugenol was 4,42 x 108/M/s.

ABSTRAK

Penelitian ini bertujuan untuk mengisolasi senyawa fenolik dalam daun cengkeh dan mempelajari mekanisme dan kinetika quenching oksigen singlet. Daun cengkeh diekstraksi dengan cara destilasi uap menggunakan air selama 6 jam. Minyak daun cengkeh kasar selanjutnya dimurnikan dengan destilasi pengurangan tekanan. Fraksi-fraksi yang terisolasi ditentukan strukturnya dengan metoda infra merah (IR), resonansi magnetik inti (1H NMR), dan spectrometer massa (MS). Efek 0, 500, 1000 dan 1500 ppm eugenol terhadap fotooksidasi asam linoleat (0,03M) yang mengandung 15 ppm eritrosin dalam etanol dipelajari dengan mengukur angka peroksida minyak. Mekanisme dan kinetika quenching oleh eugenol dipelajari dengan metode steady-state. Sampel 0; 0,06 x 10-4; 0,12 x 10-4; 0,24 x 10-4 dan 0,48x 10-4 mM eugenol dipersiapkan dalam pelarut air yang juga mengandung 0; 17,05 x10-4; 34,10 x 10-4; 68,19 x 10-4 dan 136,39 x 10-4 mM eritrosin yang disinari oleh cahaya fl uoresen (4000 lux) pada suhu kamar selama 15 jam. Hasil analisis kandungan eugenol dari minyak cengkeh, F1, F2, F3 dan F4 berturut-turut adalah 49,68; 54,32; 87,16 dan 73,65%. Kebenaran struktur F3 diidentifi kasi dengan spektrometer IR pada serapan kuat 3448 cm-1 yang menunjukkan adanya gugus hidroksil dari senyawa fenolik sedangkan pada 1H NMR menunjukkan jumlah proton pada cincin aromatic menjadi 3 atom H dan spektrometer massa menunjukkan m/e = 164 sebagai puncak tertinggi dan tidak muncul puncak (M-14)+ sebagai petunjuk adanya eugenol. Hasil ini menunjukkan bahwa eugenol memiliki aktivitas antifotooksidatif terhadap fotooksidasi asam linoleat yang disensitasi oleh eritrosin. Mekanisme quenching oksigen singlet terhadap fotodegrasi eritrosin oleh eugenol menunjukkan bahwa eugenol hanya menstabilkan oksigen singlet. Konstanta laju quenching oksigen singlet total oleh eugenol adalah 4,42 x 108/M/s.


Keywords


Clove leave; eugenol; quencher; erythrosine; singlet oxygen

Full Text:

PDF



DOI: https://doi.org/10.22146/agritech.9620

Article Metrics

Abstract views : 1381 | views : 1167

Refbacks

  • There are currently no refbacks.




Copyright (c) 2016 Jurnal Agritech

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Agritech has been Indexed by:


Agritech (print ISSN 0216-0455; online ISSN 2527-3825) is published by Faculty of Agricultural Technology, Universitas Gadjah Mada in colaboration with Indonesian Association of Food Technologies.


website statisticsView My Stats