An antioxidant compound has been isolated from the leaves of Toona sureni (Blume) Merr. The structure was determined to be methyl 3,4,5-trihydroxybenzoate (methyl gallate), based on UV-vis, FTIR, NMR and MS spectra. The isolated compound exhibited potent antioxidant activity in the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging test, with IC50 value 1.02 μg/mL.   Keywords: antioxidant activity, methyl gallate, Toona sureni

An antibacterial compound has been isolated from Ficus deltoidea Jack leaves. Based on spectroscopic data (IR, 1H-NMR, 13C NMR 1D and 2D and MS), the structure of this compound was identified as 3β-hydroksilup-20(29)-en, (lupeol), C30H50O. This compound showed antibacterial activities against E. coli, B. subtilis and S. aureus. The minimum inhibition concentration (MIC) against E. coli, B. subtilis and S. aureus are 150, 220 and 130 μg/mL respectively.

The phenolic compound has been isolated from the leaves of Toona sureni (Blume) Merr and evaluated against 3 microorganisms, including gram-positive and gram-negative bacteria. The structure was determined to be methyl 3,4,5trihydroxybenzoate (methyl gallate), based on UV-vis, FTIR, NMR and MS spectra. The antibacterial activity of the compound was evaluated using an impregnated paper disk method and compared with that of chloramphenicol. It was effective on the inactivation of Escherichia coli , Staphylococcus aureus and Bacillus subtilis. The minimal inhibition concentration (MIC) of the compound was 7.5 mg/mL against all the test bacteria. These results may be an indication of at least one of the pharmacological actions of the leaves of Toona sureni (Blume) Merr.

Volatile components from leafs of Toona sinensis (Meliaceae) were isolated by distillation watervapour method and analyzed using GC/MS. Forty-eight component were identified, and eight major components are Germacrene-D, Germacrene-B, α-Terpinene, α-Humulene, β-Caryophyllene, α-Elemene, Bicyclogermacrene and α-copaene. Insect activity of the essential oil against Crosidolomia pavonana were tested. The activity of the essential oil with concentration 25% (mortality 73.3%), concentration 50% (mortality 83.3%) and concentration 75% (mortality 90%).

The essential oil composition of the Toona sureni (Blume) Merr leaf was analyzed by GC-MS. More than 68 peaks, representing 99.99% of total oil, forty three components were identified, this represents 80.65% of the total oil component. The major components were α-terpinene (9.58%), α-copaene (8.39%), bicyclogermacrene (7.61%), δ-cadinene (6.65%), β-elemene (4.88%), germacrene-D (4.65%), δ-selinene (3.58%), caralene (3.10%), β-caryophyllene (2.88%), α-cubebene (2.82%), δ-gurjunene (2.20%), and (-)-isoledene (2.05%). The antibacterial activity of the essential oil of Toona sureni (Blume) Merr leaf was evaluated using disk diffusion method. The oil was effective on the inactivation of Escherichia coli, Staphylococcus aureus and Bacillus subtilis.

ABSTRAKKulit batang dari tanaman rambutan (Nephelium Lappaceum Linn) merupakan tanaman yang memiliki kandungan senyawa flavonoid yang dapat digunakan sebagai antioksidan. Penelitian ini bertujuan untuk mengetahui nilai IC50 dari ekstrak etanol beserta fraksi n-heksana, etil asetat dan n-butanol dari kulit batang rambutan. Ekstrak etanol diperoleh dengan cara metoda maserasi menggunakan pelarut etanol 70% kemudian dengan pelarut etanol 96%. Proses fraksinasi menggunakan pelarut n-heksan, etil asetat dan n-butanol. Pengujian aktivitas antioksidan menggunakan metode DPPH dengan melihat nilai IC50. Hasil penelitian menunjukkan bahwa pada ekstrak etanol diperoleh IC50 sebesar 24.21 ppm, fraksi n-heksan sebesar 3149.84 ppm, fraksi etil asetat sebesar 9.05 ppm, fraksi n-butanol sebesar 19.74 ppm dan asam galat sebagai pembanding sebesar 2.27 ppm. Semakin besar nilai IC50 maka aktivitas antioksidan akan semakin lemah. Berdasarkan nilai tersebut, ekstrak etanol, fraksi etil asetat dan fraksi n-butanol memiliki aktivitas antioksidan yang sangat kuat yaitu <50 ppm. Sedangkan pada fraksi n-heksan memiliki aktivitas antioksida yang lemah (>150 ppm). Kesimpulan bahwa aktivitas antioksidan dari kulit batang rambutan tergolong pada kategori sangat kuat pada ekstrak etanol, fraksi etil dan fraksi n-butanol yang bervariasi. Namun pada fraksi n-heksan didapatkan nilai yang termasuk dalam kategori lemah. Disarankan hasil penelitian ini untuk dapat dilanjutkan pada pembuatan sediaan farmasi seperti dibidang kosmetik.Kata kunci: Ekstrak etanol;kulit batang rambutan; antioksidan; metode DPPH ABSTRACT The bark of the rambutan plant (Nephelium Lappaceum Linn) is a plant that contains flavonoid compounds that can be used as antioxidants. This study aims to determine the IC50 value of ethanol extract along with fractions of n-hexane, ethyl acetate and n-butanol from rambutan bark. Ethanol extract was obtained by maceration method using 70% ethanol and then 96% ethanol. The fractionation process uses n-hexane, ethyl acetate and n-butanol. Testing antioxidant activity using the DPPH method by looking at the IC50 value. The results showed that ethanol extract obtained IC50 of 24.21 ppm, n-hexane fraction of 3149.84 ppm, ethyl acetate fraction of 9.05 ppm, nbutanol fraction of 19.74 ppm and gallic acid as a comparison of 2.27 ppm. The greater the IC50 value, the weaker antioxidant activity will be. Based on this value, ethanol extract, ethyl acetate fraction and n-butanol fraction have very strong antioxidant activity that is <50 ppm. Whereas the n-hexane fraction has weak antioxidant activity (> 150 ppm). The conclusion that the antioxidant activity of rambutan stem bark belongs to the very strong category in ethanol extract, ethyl fraction and varying n-butanol fraction. But in the n-hexane fraction, values are included in the weak category. It is recommended that the results of this study be continued in the manufacture of pharmaceutical preparations such as in cosmetics.

The ricinoleic of Castor Oil was dehydrated by various dehydrator agent (P2O5, K2CO3, H3PO4, NaHSO4, Al2O3, molecular sieve and activated bentonite at 450 °C - HCl) on the same condition (150 °C, mol ratio 1:1 and 2 hours ). The compositions of Refined Ricinus Castor Oil as starting material were : 0.92% palmitic , 5.56% linoleic , 4.07% octadecanoic , 1.22% stearic and 85.06% ricinoleic. The spesific wave number of IR was bandwith 3411 cm-1 caused of hydroxyl (-OH) group of ricinoleic at C-12 as main component. The product was Dehydrated Castor Oil (DCO) mixed of linoleic (omega 6) [C18 : 2 (9,12)] and Conjugated Linoleic Acid (CLA) [C18: 2 (9,11)]. The best dehydrator was P2O5 based on three parameters were : Free Fatty Acid (FFA) nearly the same (1.855% of Castor oil and 2.139% of DCO), the most increased of Iodium value (49.860 mg/g of Castor oil in to 63.090 mg/g of DCO), and the most decresed of hydroxyl number (28.27 mg of Castor oil in to 17.75 mg/g of DCO). To optimized the dehydration was done by various number of P2O5 (3g, 5g and 7g), tempereture (room, 100 °C and 150 °C) and time (2h, 2.5h, 3h, and 3.5h). The optimal conditon of dehydration was not found yet. Some of sugestted or idea for dehydration were: dehydration must be done by base or netral, non oxydator dehydrator, mol ratio 1:1, temperature (100-150 °C) and 2-3.5 h. Based on GC-MS the best DCO (7g P2O5, 150 °C and 3.5 h) were showed that the decrease of ricinoleic 14.13% (85.08% of Castor Oil in to 70.93% of DCO), increased linoleic 2.09% (5.56 of Castor oil in to 7.65% of DCO) and conducted of 9.09% CLA. Some new peaks between linoleic and ricinoleic are maybe isomer's of linoleic and CLA. The wave number of cunjugated alkene (C=C) (1666.3 cm-1) of IR spectra of DCO together with GC-MS chromatogram's to indicated that linoleic and CLA were conducted.   Keywords: castor oil, risinoleic, dehydration, omega 6 dan CLA

The research of fly ash as ameliorant to decrease the humic acid in peat soil of Rimbo Panjang, Riau. It is found that fly ash at 10 ton/Ha showed the best result decresing pH of peat soil (4.4 to 6.36) and humic acid content (0.2923 g/g to 0.0972 g/g).