MATERIALS AND METHODSPREPARATION OF

MATERIALS AND METHODS
PREPARATION OF FRUIT EXTRACTION
The fruits of Rhodomyrtus tomentosa were collected from Kuala Rompin, Pahang. It was cleaned and dried at room temperature for two days. The dried fruits were grinded to powder form and extracted with 300 mL of petroleum ether, chloroform, methanol and water consecutively. The extraction mixtures were incubated in water bath at 40oC for 2 h. The mixture was filtered and the filtrate evaporated to dryness using vacuum rotary evaporator at 40oC. The dried crude extracts were kept in air tight sample bottles until further used.
SEPARATION AND IDENTIFICATION OF PLANT
CHEMICAL COMPOUNDS
The chemical compounds presence in the Rhodomyrtus tomentosa extract was separated using thin layer chromatography. The presence of phenols, terpenoids and alkaloids were detected by using folin-calticeau, vannilin-H2SO4 and Dragendorf reagent, respectively. The identification chemical compounds were identified using high pressure liquid chromatography (HPLC) and gas chromatography mass spectroscopy (GCMS) with referenced to known standard compounds.
DETERMINATION OF ANTIOXIDANT ACTIVITY
1,1-DIPHENYL-2-PICRYLHYDRAZYL (DPPH)
RADICAL SCAVENGING ASSAY
The DPPH test was adopted from Yen and Hsieh (1998). DPPH of 8 mg/mL was prepared by adding 0.04 g of DPPH in 5 mL of methanol. A stock solution of ascorbic acid in methanol was prepared at the concentration of 400 μg/mL and kept in flask wrapped in aluminium foil. The reaction mixtures consist of ascorbic acid, DPPH and fruit extracts were incubated at room temperature for 30 min. The DPPH radical was used without ascorbic acid as control. The quenching of free radicals by ascorbic acid is measured spectrophotometrically at 517 nm. The degree of discoloration indicates the free radical scavenging efficiency of ascorbic acid. The percentage of inhibition of DPPH was determined using the formula:
% of DPPH Inhibition = [(OD control – OD sample)
/ OD control] × 100,
where ODcontrol is the absorbance value of control and ODsample is the absorbance value of sample or crude extract.
A graph of percentage of DPPH inhibitions against concentration was plotted to determine the LC50 value which was defined as the concentration at which 50% of DPPH radicals is inhibited.

Results (Indonesian) 1:

BAHAN DAN METODEPENYUSUNAN BUAH EKSTRAKSIBuah-buah Rhodomyrtus tomentosa dikumpulkan dari Kuala Rompin, Pahang. Itu dibersihkan dan kering pada suhu kamar selama dua hari. Buah-buahan kering yang digiling untuk bentuk bubuk dan diekstraksi dengan 300 mL eter minyak bumi, kloroform, metanol dan air berturut-turut. Campuran ekstraksi yang diinkubasi dalam penangas air pada 40oC untuk 2 h. Campuran disaring dan Filtrat menguap kekeringan menggunakan rotary evaporator vakum di 40oC. Ekstrak kering kasar dipelihara dalam botol sampel udara ketat sampai selanjutnya digunakan.PEMISAHAN DAN IDENTIFIKASI TANAMANSENYAWA KIMIAKehadiran senyawa kimia dalam Rhodomyrtus tomentosa ekstrak terpisah menggunakan kromatografi lapis tipis. Kehadiran fenol, terpenoids dan alkaloid terdeteksi dengan menggunakan folin-calticeau, vannilin-H2SO4 dan reagen Dragendorf, masing-masing. Identifikasi senyawa kimia yang diidentifikasi menggunakan tinggi tekanan kromatografi cair (HPLC) dan kromatografi gas massa spektroskopi (GCMS) dengan direferensikan senyawa standar dikenal.PENENTUAN AKTIVITAS ANTIOKSIDAN1,1-DIFENIL-2-PICRYLHYDRAZYL (DPPH)RADIKAL PEMULUNGAN ASSAYThe DPPH test was adopted from Yen and Hsieh (1998). DPPH of 8 mg/mL was prepared by adding 0.04 g of DPPH in 5 mL of methanol. A stock solution of ascorbic acid in methanol was prepared at the concentration of 400 μg/mL and kept in flask wrapped in aluminium foil. The reaction mixtures consist of ascorbic acid, DPPH and fruit extracts were incubated at room temperature for 30 min. The DPPH radical was used without ascorbic acid as control. The quenching of free radicals by ascorbic acid is measured spectrophotometrically at 517 nm. The degree of discoloration indicates the free radical scavenging efficiency of ascorbic acid. The percentage of inhibition of DPPH was determined using the formula:% of DPPH Inhibition = [(OD control – OD sample)/ OD control] × 100,where ODcontrol is the absorbance value of control and ODsample is the absorbance value of sample or crude extract.A graph of percentage of DPPH inhibitions against concentration was plotted to determine the LC50 value which was defined as the concentration at which 50% of DPPH radicals is inhibited.

Results (Indonesian) 2:

BAHAN DAN METODE
PERSIAPAN BUAH EKSTRAKSI
Buah dari kemunting dikumpulkan dari Kuala Rompin, Pahang. Itu dibersihkan dan dikeringkan pada suhu kamar selama dua hari. Buah-buahan kering yang digiling ke bentuk bubuk dan diekstraksi dengan 300 ml petroleum eter, kloroform, metanol dan air berturut-turut. Campuran ekstraksi diinkubasi di bak air pada suhu 40oC selama 2 jam. Campuran disaring dan filtrat diuapkan sampai kering dengan menggunakan vacuum evaporator rotary pada suhu 40oC. Ekstrak mentah kering disimpan di udara botol sampel ketat hingga lebih digunakan.
PEMISAHAN DAN IDENTIFIKASI TANAMAN
KIMIA SENYAWA
Senyawa kimia kehadiran di ekstrak kemunting dipisahkan menggunakan kromatografi lapis tipis. Kehadiran fenol, terpenoid dan alkaloid yang terdeteksi dengan menggunakan Folin-calticeau, vannilin-H2SO4 dan Dragendorf reagen, masing-masing. Senyawa kimia identifikasi diidentifikasi menggunakan kromatografi cair tekanan tinggi (HPLC) dan spektroskopi massa kromatografi gas (GCMS) dengan direferensikan untuk senyawa standar yang dikenal.
PENENTUAN KEGIATAN ANTIOKSIDAN
1,1-Diphenyl-2-pikrilhidrazil (DPPH)
RADICAL scavenging ASSAY
yang DPPH tes diadopsi dari Yen dan Hsieh (1998). DPPH dari 8 mg / mL dibuat dengan menambahkan 0,04 g DPPH dalam 5 ml metanol. Sebuah larutan stok asam askorbat dalam metanol disiapkan pada konsentrasi 400 mg / mL dan disimpan dalam termos dibungkus aluminium foil. Campuran reaksi terdiri dari asam askorbat, DPPH dan buah ekstrak diinkubasi pada suhu kamar selama 30 menit. DPPH radikal digunakan tanpa asam askorbat sebagai kontrol. Pendinginan radikal bebas oleh asam askorbat diukur spektrofotometri pada 517 nm. Tingkat perubahan warna menunjukkan efisiensi radikal bebas asam askorbat. Persentase penghambatan DPPH ditentukan dengan rumus:
% dari DPPH Penghambatan = [(kontrol OD - OD sampel)
/ control OD] × 100,
di mana ODcontrol adalah nilai absorbansi kontrol dan ODsample adalah nilai absorbansi sampel atau crude ekstrak.
grafik persentase hambatan DPPH terhadap konsentrasi diplot untuk menentukan nilai LC50 yang didefinisikan sebagai konsentrasi di mana 50% dari radikal DPPH terhambat.