Antimicrobial Activity of Ethanolic Extract of Sempur (Dillenia suffruticosa (Griff.) Martelli) Leaves against Pathogenic Microorganisms

Sempur (Dillenia suffruticosa) leaves are known as a traditional medicine for the people of Bangka-Belitung Island. The local people empirically utilize the boiled water of D. suffruticosa leaves as antidiarrhea. However, the antimicrobial activity of the ethanol extract of D. suffruticosa leaves has not been reported. This study aims to determine the antimicrobial activity of the ethanol extract of D. suffruticosa leaves against several microorganisms: Staphylococcus aureus as Gram-positive bacteria, Escherichia coli as Gram-negative bacteria, and Candida albicans as fungi. Extraction was carried out by maceration method with 70% ethanol, then screened for phytochemical constituents. The antimicrobial test was carried out by the disc diffusion method using Nutrient Agar (NA) for bacteria, and Sabouraud Dextrose Agar (SDA) for fungi. The results of phytochemical screening showed that the ethanol extract of D. suffruticosa leaves contained alkaloids, flavonoids, tannins, and saponins. The antimicrobial test showed that the extract of D. suffruticosa leaves could inhibit the growth of S. aureus at concentrations of 10%, 20%, and 40% were 8.35±0.05; 9.34±0.32; and 10.52±0.22, respectively. The ethanol extract of D. suffruticosa leaves could inhibit the growth of S. aureus, whereas E. coli and C. albicans did not show any activity.


INTRODUCTION
Indonesia is an archipelago country consisting of more than 17.000 islands. Indonesia's geographic and historical conditions make this country one of the countries with high biodiversity, otherwise known as mega Dillenia suffruticosa has few local names such as sempur, simpor, simpoh, simpur air, and simpur bini 4, [8][9][10][11] . The name sempur is derived from the hissing sound when the trunk tree is cut 4   The dried leaves then being crushed using a blender and followed by sieving using mesh 60. The sieving produces simplicia of D. suffruticosa leaves powder. This procedure was to gain a homogeneous size of simplicia, so the interaction between the D. suffruticosa leaves powders and the solvent would be optimal. Besides, homogeneous size particle could optimize the extraction process 16 .

Materials
The D. suffruticosa leaves powder was weighed as much as 100 g then extracted with the maceration method using 70% ethanol as a solvent with a ratio of 1 : 10. The maceration was done for 24 hours and re-macerated twice with the same procedure. The maceration results were filtered with filter paper. The filtrate was evaporated using the vacuum rotary evaporator until it produces a thick extract 17 .

Organoleptic observation
The organoleptic observation of ethanolic extract of D.
suffruticosa leaves aimed to determine the physical form of color, smell, shape, and taste using the senses. This suffruticosa leaves contain polyphenols 9,10,15,25,26 . This dried method was suitable with Priamsari et al. 27 , which stated that the total flavonoid content was higher in wind-dried leaves than the oven method. It also corresponded with Rivai et al. 28 , which proved that the wind-dried method was the optimum method to gain phenolics.
The wind-dried method also had another advantage: retaining chlorophyll, so the sample still looks greenish, not brown 29 . The D. suffruticosa leaves powder in this research was showed a greenish color (Figure 2). However, this method had limitations, such as time- Hasnaeni et al. 33 also reported that the maceration method produced a higher yield than reflux and soxhlet extraction.
The yield of ethanol extract of D. suffruticosa leaves was about 65.5% (Table I)

Organoleptic observation
The organoleptic observation involved eight respondents. Each respondent was asked to observe the shape and color of the extract. Other than that, respondents were also asked to smell and taste the extract (Figure 3). The respondents agree that the extract was in thick, blackish-green color, had a distinctive smell of D.
suffruticosa leaves, and had an astringent taste ( Table II).
The findings of organoleptic observations have never been published, so this article was a preliminary report for future studies as a guide.

Antimicrobial activity
The antimicrobial activity was done using a Kirby-Bauer disk diffusion method. This method was used to determine the sensitivity or resistance of pathogenic microorganisms to various antimicrobial compounds.
The clear zone that appears around the disk was measured as the inhibition zone 20, 41 . The results of the antimicrobial activity showed in Table IV.

DATA AVAILABILITY
All data are available from the authors.