EKSTRAKSI BIJI OROK-OROK (CROTALARIA JUNCEA) SEBAGAI BAHAN BAKU PEMBUATAN BIODIESEL MENGGUNAKAN PELARUT N-HEKSAN

AbstrakTanaman orok-orok (crotalaria juncea) adalah tanaman leguminosa yang termasuk kedalam keluarga perdu dan semak. Biji orok-orok dapat digunakan sebagai obat insomnia dan sebagai bahan baku pembuatan biodiesel karena mengandung 12,6 % minyak dengan 46,8 % asam linoleate. 4,6 % asam linolenat, 28,3 % asam oleat dan 20,3 % asam jenuh. Untuk mendapatkan minyak dari biji orok-orok yang akan digunakan sebagai bahan baku biodiesel dapat dilakukan dengan metode ekstraksi padat-cair menggunakan pelarut N-Heksan. Pada penelitian ini bahan baku yang digunakan adalah biji orok-orok dan N-Heksan. Biji orok-orok dihaluskan menggunakan blender, kemudian dimasukkan dalam labu leher tiga untuk proses ekstraksi menggunakan pelarut N-Heksan. Ekstraksi dilakukan dengan memvariasikan suhu ekstraksi dan volume pelarut dengan waktu ekstraksi 5 jam dan bahan baku sebanyak 100 gr. Setelah selesai ekstraksi larutan disaring menggunakan kertas saring. Selanjutnya dilakukan pemisahan antara minyak dan pelarut dengan proses destilasi. Pengujian yang dilakukan adalah uji densitas, yield, kadar FFA, viscositas, densitas dan uji komposisi dengan alat GC-MS. Densitas terendah dihasilkan pada suhu 500C, berat sampel 100 gr, waktu ekstraksi 5 jam dan volume pelarut sebanyak 400 ml sebesar 1 g/ml. Yield tertinggi dihasilkan pada suhu 600C, berat sampel 100 gr, volume pelarut 700 ml dan waktu ekstraksi 5 jam sebesar 35,52 %. Kadar FFA terendah dihasilkan pada suhu 500C, berat sampel 100 gr, volume pelarut 500 ml dan waktu 5 jam sebesar 1,39 %. Viscositas hasil terbaik yang didapatkan adalah pada volume 700 ml dengan waktu ekstraksi 5 jam menggunakan pelarut N-Heksan pada suhu 600c sebesar 1 cp. Dari hasil uji GC-MS diketahui bahwa minyak biji orok-orok mengandung methyl ester of undecanoic acid, 2-methylpentanoic acid, myristic acid methyl ester, methyl linolelaidate, 2-cyclopentylacetohydrazide dan 2-methylpentanoic acid.

Thermal Traits of MNPs under High-Frequency Magnetic Fields: Disentangling the Effect of Size and Coating

We investigated the heating abilities of magnetic nanoparticles (MNPs) in a high-frequency magnetic field (MF) as a function of surface coating and size. The cobalt ferrite MNPs were obtained by a hydrothermal method in a water–oleic acid–ethanol system, yielding MNPs with mean diameter of about 5 nm, functionalized with the oleic acid. By applying another cycle of hydrothermal synthesis, we obtained MNPs with about one nm larger diameter. In the next step, the oleic acid was exchanged for 11-maleimidoundecanoic acid or 11-(furfurylureido)undecanoic acid. For the heating experiments, all samples were dispersed in the same solvent (dichloroethane) in the same concentration and the heating performance was studied in a broad interval of MF frequencies (346–782 kHz). The obtained results enabled us to disentangle the impact of the hydrodynamic, structural, and magnetic parameters on the overall heating capabilities. We also demonstrated that the specific power absorption does not show a monotonous trend within the series in the investigated interval of temperatures, pointing to temperature-dependent competition of the Brownian and Néel contributions in heat release.

Biochemical Properties of Tyrosinase from Aspergillus terreus and Penicillium copticola; Undecanoic Acid from Aspergillus flavus, an Endophyte of Moringa oleifera, Is a Novel Potent Tyrosinase Inhibitor

Tyrosinase is a copper-containing monooxygenase catalyzing the O-hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine then to dopaquinone that is profoundly involved in melanin synthesis in eukaryotes. Overactivation of tyrosinase is correlated with hyperpigmentation that is metabolically correlated with severe pathological disorders, so, inhibition of this enzyme is the most effective approach in controlling the overproduction of melanin and its hazardous effects. Thus, searching for a powerful, selective inhibitor of human tyrosinase to limit the hyper-synthesis of melanin is a challenge. Unlike the difficulty of overexpression of human tyrosinase, using fungal tyrosinase as a model enzyme to the human one to evaluate the mechanistics of enzyme inhibition in response to various compounds is the most feasible strategy. Thus, the purification of highly catalytic-efficient fungal tyrosinase, exploring a novel inhibitor, and evaluating the mechanistics of enzyme inhibition are the main objectives of this work. Aspergillus terreus and Penicillium copticola were reported as the most potential tyrosinase producers. The biochemical properties suggest that this enzyme displays a higher structural and catalytic proximity to human tyrosinase. Upon nutritional bioprocessing by Plackett–Burman design, the yield of tyrosinase was increased by about 7.5-folds, compared to the control. The purified tyrosinase was strongly inhibited by kojic acid and A. flavus DCM extracts with IC50 values of 15.1 and 12.6 µg/mL, respectively. From the spectroscopic analysis, the main anti-tyrosinase compounds of A. flavus extract was resolved, and verified as undecanoic acid. Further studies are ongoing to unravel the in vivo effect and cytotoxicity of this compound in fungi and human, that could be a novel drug to various diseases associated with hyperpigmentation by melanin.

The effects of nutrient stress on marine microalgae for enhancing the biodiesel production

This study aimed to investigate the effect of nutrient stress such as nitrogen and phosphorus on the growth rate of green algae, Chlorella sp. and the mechanism secreted to survive during the depletion of nutrients. The sample was tested with several vital parameters, suppressed Total Nitrogen (TN) and Total Phosphorus (TP). A process known as acclimatization was carried out to ensure that the algae can adapt to a new environment which was repeated 2 times, each taking about 2 weeks. The active compounds in the samples were measured using Gas Chromatography-Mass Spectrophotometry. The experiments showed that the control microalgae secreted hexadecanoic acid and methyl stearate while nitrogen suppressed microalgae secreted Undecanoic acid, 10-methyl- and methyl ester. Phosphorus limited microalgae secreted 1,3-Propanediamine, N-(2-aminoethyl)- due to suppress of nutrients. This experiment should be tested in several study areas in Mexico and outside Mexico to compare the productivity of green algae and the main factors that contribute to the eutrophication problem.

Pemanfaatan Biji Orok-Orok (Crotalaria juncea) sebagai Bahan Baku Pembuatan Minyak Nabati dengan Metode Ekstraksi Padat-Cair

ABSTRAKTanaman orok-orok atau Crotalaria juncea L adalah tanaman leguminosa yang termasuk ke dalam keluarga perdu dan semak Biji orok-orok mengandung 12,6 % minyak dengan 46,8 % asam linoleat, 4,6 % asam linolenat, 28,3 % asam oleat dan 20,3% asam jenuh. Metode yang digunakan adalah metode ekstraksi padat-cair dengan pelarut etanol. Pada penelitian ini dioptimasi menggunakan RSM (Response Surface Methodology). Bahan baku yang digunakan adalah biji orok-orok dan etanol. Biji orok-orok dihaluskan menggunakan blender, kemudian dimasukkan dalam labu leher tiga untuk proses ekstraksi menggunakan pelarut etanol. Ekstraksi dilakukan dengan memvariasikan berat sampel, suhu ekstraksi dan waktu ekstraksi. Dengan variasi berat sampel (70, 80,90 gram), Suhu (55, 65 dan 75oC), Waktu (3,4 dan 5 jam). Setelah selesai ekstraksi larutan di saring menggunakan kertas saring. Selanjutnya dilakukan pemisahan antara minyak dan pelarut dengan proses destilasi. Pengujian yang dilakukan adalah uji densitas, yield, kadar FFA dan uji komposisi dengan alat GC-MS. Densitas terendah dihasilkan pada Suhu 75oC, berat sampel 70 dan waktu ekstraksi 4 jam sebesar 0,788 g/ml. Yield tertinggi dihasilkan pada suhu 65oC, berat sampel 90 gr dan waktu ekstraksi 3 jam sebesar 19,943 %. Kadar FFA terendah dihasilkan pada suhu 65oC , berat sampel 90 dan waktu 5 jam. RSM memberikan hasil optimasi terbaik pada suhu 75oC, berat sampel 89,64 gram dan waktu ekstraksu 3 jam dengan yield 19,943, densitas 0,89 gr/ml dan kadar FFA 1,2674 %. Dari hasil uji GC-MS diketahui bahwa minyak biji orok-orok mengandung methyl ester of undecanoic acid, 2-methylpentanoic acid, myristic acid methyl ester, methyl linolelaidate, 2-cyclopentylacetohydrazide dan 2-methylpentanoic acid.Kata Kunci : biji orok-orok, ekstraksi, densitas, yield, kadar FFA

One step sample treatment and loading using a deep eutectic solvent immobilized in a porous substrate for thermal ionization mass spectrometry of Pu(iv) ions

A deep eutectic solvent (DES) consisting of a 2 : 1 molar mixture of undecanoic acid and tetraheptylammonium bromide was immobilized in poly(propylene) membrane for the selective preconcentration of Pu for TIMS analysis with the good analytical merits.