Pharmacognostic Study and Antioxidant Activity of Mundar (Garcinia forbesii King.) leaves from Banua Botanical Gardens of South Kalimantan

Mundar (Garcinia forbesii King.) is a plant from South Kalimantan. This plant has chemical contents that have potential as medicine. The purpose of this study is to provide a pharmacognostic picture of a specific, nonspecific and determine the antioxidant activity of G. forbesii leaves. Specific parameters include organoleptic, microscopic testing, thin-layer chromatography profiles, and phytochemical screening. Nonspecific parameters include total ash content, acid insoluble ash content, drying loss, water-soluble extract content, and ethanol-soluble extract content. Antioxidant activity was determined by the DPPH method based on IC50 values. Specific parameter test results are green powder, characteristic odor, and sour taste. Microscopic tests showed stomata, upper epidermis, lower epidermis, cell walls, xylem, phloem, palisade tissue, spongy tissue, and cuticles. Garcinia forbesii leaves contain alkaloids, flavonoids, phenols, tannins, and steroids. The TLC profile showed good separation of polar eluents, and yellow spots appeared after spraying DPPH reagents. The non-specific parameter test is the total ash content of 6.52±0.1%; acid insoluble ash content 1.06±0.08%; drying shrinkage 6.43±0.38%; watersoluble extracts 34.3±0.3%; and ethanol-soluble extracts 23.47±0.35%. Ethanol extract of G. forbesii leaves has antioxidant activity with IC50 of 65.7 ppm. Pharmacognostic study fulfills the requirements, and G. forbesii leaves extract has strong antioxidant activity.


INTRODUCTION
forbesii stem bark contains rubraxanthone that has antimicrobial activities (Alen et al., 2008). The fruit peels were extracted with ethanol 30% and 70% have antioxidant studied on the method of 1,1-diphenyl-2picrylhidrazyl (DPPH) with IC50 value more than 500 ppm (Muthia et al., 2019) and the ethyl acetate fraction of the fruit peels of ethanol 70% extract have antioxidant activity with IC50 value 72.386 ppm (Muthia et al., 2018).
Besides that, the fruit peels ethanol extract shows the antioxidant activity on the method of ferric reducing antioxidant power (FRAP) (Dewi, 2018) as well as water extract with DPPH method (Andarini et al., 2018).
However, the part that is often scrutinized is fruit skin that is more difficult to obtain because it is seasonal, and the study of its leaves was reported just from the fraction of n-hexane. It has also been investigated as having antibacterial properties against Escherichia coli and Staphylococcus aureus (Larasati, 2017;Lim, 2012). Our research is the first study of the antioxidant activity of G.
forbesii leaves. All the research was reported not contain the whole of standardization. This causes the need for quality testing and the quality of the materials used to ensure safety and efficacy. The pharmacognostic study is the basis and part of the plant standardization process in a simple way. This test is useful to support identification and determine plant material's efficacy and safety (Sapna et al., 2008). The study of antioxidant activity is useful to provide preliminary data in the development of natural materials to increase the feasibility of using plants as herbal medicines. Antioxidant activity can be determined from the IC50 value by the DPPH method (Hadadi et al., 2020).
The DPPH method is a simple method through radical reduction with accurate, reliable, and relatively short time (Kedare & Singh, 2011

Tools and materials
The tools used in this study were furnaces (Ney-Vulcan hours. The liquid extract obtained was filtered and evaporated with a rotary evaporator and then thickened on a water bath at a temperature of 50℃ until a thick extract with constant weight was obtained.

Pharmacognostic study
The Pharmacognostic study includes specific parameters and nonspecific parameters. Specific parameters consist of organoleptic study, microscopic study, phytochemical screening on simplicia powders and extracts, and TLC profiles. The nonspecific parameters include total ash content, acid insoluble ash content, shrinkage of drying, water-soluble extract, and ethanol-soluble extract.

Determination of antioxidant activity
The
Fresh leaves as much as 1.55 kg and after processing obtained dry simplicia (Figure 2A) as much as 458 g.

Pharmacognostic study
The organoleptic study of the G. forbesii leaves simplicia shows green powder, sour taste, and characteristic odor of G. forbesii leaves. The green color is faded compared to fresh leaves because it has undergone drying so that the chlorophyll content in this simplicia is reduced. Sour taste is caused by the content of phenolic compounds (Kabera et al., 2014). The pungent smell of simplicia of G. forbesii leaves, which is quite strong, is possible from the essential oil content.
The microscopic study was carried out using a light processing, as presented in Table I.  This data can be used as a reference for herbal medicine in the form of stew (infuse). The compounds dissolved in water are polar compounds such as amino acids, some vitamins, enzymes, sugars, glycosides, inorganic salts, carotenoids, proteins, saponins, tannins, and alkaloid salts (Ali et al., 2018;Hardiana et al., 2012). terpenoids, steroids, waxes, and resins (Zhang et al., 2018). The value of ethanol-soluble extracts can be used to make extracts used as a natural medicine and an initial description of the magnitude of compounds found in organic solvents (Handayani et al., 2018). The determination of non-specific parameters is presented in Table II.

Determination of antioxidant activity
The maximum wavelength is determined to determine the wavelength of the compound that provides maximum absorbance. A measurement carried out at maximum wavelength will give linear results, high instrument sensitivity, and reduce measurement errors  Table III.  (Muthia et al., 2018). This result shows that the antioxidant activity of G. forbesii leaves is more significant than its rind.

CONCLUSION
The