Stabilitas, Tautomerisasi, dan Degradasi Kurkumin dalam Pelarut Etanol-air: Studi Spektral UV-Visible

Putri, Agresya Shafana (2023) Stabilitas, Tautomerisasi, dan Degradasi Kurkumin dalam Pelarut Etanol-air: Studi Spektral UV-Visible. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Kurkumin adalah pigmen polifenol utama yang ditemukan dalam akar kunyit atau Curcuma longa dan merupakan senyawa antioksidan alami yang tidak beracun. Penggunaan kurkumin dibatasi oleh kelarutan air yang rendah dan sensitivitas cahaya. Penelitian mengenai degradasi senyawa kurkumin dengan optimasi pengaruh konsentrasi pelarut etanol-air 10, 20, 30, 40% (v/v) dan penyinaran lampu dilakukan. Degradasi diamati dengan pengukuran absorbansi larutan kurkumin sebagai fungsi waktu menggunakan spektrofotometer UV-Vis. Absorbansi maksimal kurkumin dalam konsentrasi etanol-air hingga 30% didapat adanya puncak lebar pada 360 nm dan puncak yang cukup tajam pada 430 nm. Puncak pada 360 nm adalah respon dari gugus keto dan 430 nm adalah respon dari gugus enol. Kurkumin yang dilarutkan dalam pelarut etanol air 40% menunjukkan puncak tunggal tajam pada 430 nm. Kesetimbangan tautomer antara bentuk enol dan bentuk keto kurkumin dapat bergeser ke arah tautomer keto dengan penambahan air. Pengaruh paparan cahaya pada proses degradasi dan penurunan kadar kurkumin diamati menggunakan sebuah bola lampu spektrum penuh (11-Watt Daylight bulb) selama 30 hari. Selain itu, hasil percobaan dibandingkan dengan perhitungan keadaan dasar teoritis menggunakan metode DFT dan perhitungan TDDFT untuk keadaan tereksitasi menggunakan program ORCA versi 4.0.1 dan perangkat lunak Avogadro 1.2.0.
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Curcumin is the main polyphenol pigment found in turmeric root or Curcuma longa and is a non-toxic natural antioxidant compound. The use of curcumin is limited by its low water solubility and light sensitivity. Research on the degradation of curcumin compounds by optimizing the effect of ethanol-water concentrations of 10, 20, 30, 40% (v/v) and irradiating a lamp was carried out. The degradation was observed by measuring the absorbance of the curcumin solution as a function of time using a UV-Vis spectrophotometer. The maximum absorbance of curcumin in ethanol-water concentrations up to 30% was obtained with a wide peak at 360 nm and a fairly sharp peak at 430 nm. The peak at 360 nm is the response from the keto group and 430 nm is the response from the enol group. Curcumin dissolved in 40% ethanol-water showed a sharp single peak at 430 nm. The tautomeric equilibrium between the enol and keto forms of curcumin can shift towards the keto tautomer with the addition of water. The effect of light exposure on the degradation process and the decrease in curcumin levels was observed using a full spectrum light bulb (11-Watt Daylight bulb) for 30 days. In addition, the experimental results were compared with theoretical ground state calculations using the DFT method and TDDFT calculations for excited states using the ORCA program version 4.0.1 and Avogadro 1.2.0 software.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Kurkumin, Campuran Biner Etanol-Air, Degradasi, Tautomerisasi, DFT, Curcumin, Ethanol-Water Binary Mixture, Degradation, Tautomerization
Subjects:	Q Science > QD Chemistry Q Science > QD Chemistry > QD117.S64 Spectrophotometry Q Science > QD Chemistry > QD75.2 Chemistry, Analytic
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47101-(S2) Master Thesis
Depositing User:	Agresya Shafana Putri
Date Deposited:	13 Sep 2023 01:12
Last Modified:	13 Sep 2023 01:12
URI:	http://repository.its.ac.id/id/eprint/104034

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