Asian Journal of Chemistry; Vol. 32, No. 4 (2020), 941-944 AJSIAN OURNAL OF C HEMISTRY

https://doi.org/10.14233/ajchem.2020.22231

Anthocyanin in Flacourtia inermis Peel: Analysis and Electronic Transition Study

*, KHUSNA ARIF RAKHMAN , A. RASID SARAHA, SUDIR UMAR, RAHMANIAH ZAINUDDIN and M. IKHLAS ABDJAN

Department of Chemistry Education, Universitas Khairun, Ternate, Indonesia

*Corresponding author: E-mail: [email protected]

Received: 27 May 2019; Accepted: 24 December 2019; Published online: 25 February 2020; AJC-19816

This study aimed to determine the content present in Flacourtia inermis peel and its ultraviolet-visible absorption potential as a dye agent. This work focused on developing dye-sensitized materials that require natural eco-friendly dyes which are easily reproducible. The red to purple colour of Flacourtia inermis peel indicates the presence of anthocyanin contents, which were derived from . Hence, anthocyanin analysis, UV-vis absorption test and electronic transition study were conducted for information regarding the potential use Flacourtia inermis fruit peel in natural dyes. To determine anthocyanin and absorption ability, UV-visible spectrophotometry was used. Furthermore, the electronic transition of anthocyanin was determined using the semi-empirical method of ZINDO/s. The results indicate that total anthocyanin content of Flacourtia inermis peel was 10.35 mg/100 g, with UV absorption occurring at erythema transmission percent of 0.7553; the pigmentation transmission percent was 0.78696, whereas the electronic transitions of molecular orbitals were observed at an optimum wavelength 425.5 nm visible area, with intensity 1.1233. Molecular orbital levels were six, with two electronic transition shifts, namely n→π* and π→π*.

Keywords: Anthocyanin, Flacourtia inermis, Semi-empirical method.

INTRODUCTION groups among the seven functional groups in the basic structure of determine the characteristics of . Dye-sensitised solar cell (DSSC) is one of the third gene- Flacourtia inermis or the tome-tome fruit contains anthocyanin ration solar cells [1] and consist of a colouring agent (dyes) and rich in antioxidants. The antioxidant activities and phenolic generally used between different electrodes. This solar cell has compound contents of Flacourtia inermis extract are reported semi-conductor electrodes, light-sensitive dyes, redox mediators in the literature [12,13]. and counter electrodes [2]. Unlike other solar cells, DSSC uses The anthocyanin content of Flacourtia inermis peel makes dyes, which absorb a certain range of visible light [3]. One of the it a source of dye for its potential application in DSSC. The natural pigments used as dyes in DSSC is anthocyanin, which electromagnetic radiation interacts with the dye in ultraviolet are widely used in food, medicine and textile industries [4]. (190-400 nm) and visible light (400-800 nm) to provide a visible Anthocyanin is used as a dye because it absorbs visible colour contraction. The anthocyanidin activity can be measured light. Anthocyanin structure consists of a double bond conju- and analyzed by shifting the wavelength of UV-visible spectro- gated to the chromophore group, which leads to absorption of photometer through a electromagnetic radiation absorbance visible light [5]. It is a derivative and commonly [14-16]. Through determination of UV-visible absorption and found in fruits and vegetables with strong red to purple colour electronic transition of Flacourtia inermis peel, its potential [6]. Anthocyanin derivatives include , , as a dye agent can be studied.