Spectral analysis and Antibacterial activity of the bioactive principles of Sargassum tenerrimum J. Agardh collected from the Red sea, Jazan, Kingdom of Saudi Arabia

Seaweeds are a major marine resource that can be explored to develop novel pharmaceutical molecules. The present study showed the presence of unique bioactive components in the petroleum ether extract (PEE) and methanolic extract (ME) of Sargassum tenerrimum. The gas chromatography-mass spectrometry analysis suggested that the PEE of S. tenerrimum contained antibacterial biomolecules: hexadecanoic acid, methyl ester, 17-pentatriacontene, dasycarpidan-1-methanol, and acetate (ester). However, the ME of S. tenerrimum exhibited better antibacterial effect than the PEE due to the presence of the bioactive compounds 1,2-benzenedicarboxylic acid, diisooctyl ester, tetratetracontane, 1-docosene, 1,2-benzenediol, and benzoic acid. Thus, promising antibacterial molecules can be isolated from S. tenerrimum for better therapeutic use.

Fabrication of inverted organic solar cells on stainless steel substrate with electrodeposited and spin coated ZnO buffer layers

Polymer based organic solar cells (OSCs) are of tremendous interest as suitable candidates for producing clean and renewable energy in recent years. In this study, inverted OSCs on stainless steel (SS) substrate with zinc oxide (ZnO) as the electron selective transport layer (ESTL), are investigated, occupying bulk heterojunction blend of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) as the active material and poly-(4,3-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole transport layer (HTL). The device structure is SS/ZnO/P3HT:PCBM/PEDOT:PSS/Au. ZnO films are prepared by spin coating and electrodeposition techniques, followed by annealing under ambient conditions. The insertion of ZnO layer between the SS substrate and active layer has improved short-circuit current (J sc), open-circuit voltage (V oc), fill factor (FF), and power conversion efficiency (PCE) compared to those of the reference cell without ZnO layer, achieving the highest efficiency of 0.66% for the device with spin coated ZnO from sol–gel technique. This enhancement can be attributed to the effective electron extraction and the increased crystallinity of ZnO after annealing treatments at higher temperatures as further confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses.

Palm Oil Mill Effluent for Lipid Production by the Diatom Thalassiosira pseudonana

Biomass and lipid production by the marine centric diatom Thalassiosira pseudonana were characterized in media based on palm oil mill effluent (POME) as a source of key nutrients. The optimal medium comprised 20% by volume POME, 80 µM Na2SiO3, and 35 g NaCl L−1 in water at pH ~7.7. In 15-day batch cultures (16:8 h/h light–dark cycle; 200 µmol photons m−2 s−1, 26 ± 1 °C) bubbled continuously with air mixed with CO2 (2.5% by vol), the peak concentration of dry biomass was 869 ± 14 mg L−1 corresponding to a productivity of ~58 mg L−1 day−1. The neutral lipid content of the biomass was 46.2 ± 1.1% by dry weight. The main components of the esterified lipids were palmitoleic acid methyl ester (31.6% w/w) and myristic acid methyl ester (16.8% w/w). The final biomass concentration and the lipid content were affected by the light–dark cycle. Continuous (24 h light) illumination at the above-specified irradiance reduced biomass productivity to ~54 mg L−1 day−1 and lipid content to 38.1%.

Process optimization for the production of biodiesel from Azolla Microphylla oil and its fuel characterization

The most competent and operative use of renewable feedstock is super critical for the production of biodiesel which has increased attention worldwide pertaining to aquatic fern Azolla. Maximizing the biodiesel yield by optimizing the process parameters of the low-frequency ultrasonic energy-assisted transesterification process of Azolla oil is the need of the hour for minimizing the production cost of biodiesel. Response Surface Methodology (RSM) was applied using central composite rotatable design (CCRD) to find the best optimum reaction parameters for this transesterification process. The optimized reaction parameters arrived from the design of experiments were as following: methanol/Azolla oils molar ratio (A) = 6.49 mole/mole, KOH catalyst concentration (B) = 1.69 (weight% of oil), reactiion time (C) = 34.74 min and reaction temperature (D) = 38.87°C. The best higher theoretical predicted Azolla Fatty Acid Methyl Ester (FAME) yield was Y = 99.76% which is in well coincidence with the actual yield. The extracted Azolla biodiesel was tested for various fuel properties with standard test procedures and found to be in agreement with various Biodiesel standards and the results are promising in terms of utilizing Azolla oil as an inexhaustible and potentially economical source of biodiesel.

Effect of Anaerobic Digestate on the Fatty Acid Profile and Biodiesel Properties of Chlorella sorokiniana Grown Heterotrophically

The growth kinetics and the lipid and protein content of the microalgal species Chlorella sorokiniana (CS) grown heterotrophically in growth media containing glycerol and increasing amounts of anaerobic digestate (AD) equal to 0%, 15%, 30%, and 50% was studied. The effect of the AD on the fatty acid (FA) distribution of the bio-oil extracted from the CS, as well as on the fatty acid methyl ester (FAME) properties such as the saponification number (SN), the iodine value (IV), the cetane number (CN), and the higher heating value (HHV) was also estimated. The percentage of AD in the growth medium affects the rate of carbon uptake. The maximum carbon uptake rate occurs at about 30% AD. Protein and lipid content ranged from 32.3–38.4% and 18.1–23.1%, respectively. Fatty acid distribution ranged from C10 to C26. In all AD percentages the predominant fatty acids were the medium chain FA C16 to C18 constituting up to about 89% of the total FA at 0% AD and 15% AD and up to about 54% of the total FA at 30% AD and 50% AD. With respect to unsaturation, monounsaturated FA (MUFA) were predominant, up to 56%, while significant percentages, up to about 38%, of saturated FA (SFA) were also produced. The SN, IV, CN, and HHV ranged from 198.5–208.3 mg KOH/g FA, 74.5–93.1 g I/100 g FAME, 52.7–56.1, and 39.7–40.0 MJ/kg, respectively. The results showed that with increasing AD percentage, the CN values tend to increase, while decrease in IV leads to biofuel with better ignition quality.

Esterification of Free Fatty Acid in Palm Oil Mill Effluent using Sulfated Carbon-Zeolite Composite Catalyst

Free fatty acid esterification (FFA) in palm oil mill waste (POME) was carried out using a sulfonated carbon-zeolite composite catalyst. The catalyst is synthesized with carbon precursor obtained from molasses, which is adsorbed on the surface of the zeolite and then carbonized and sulfonated with concentrated H2SO4 to form a sulfonated carbon-zeolite catalyst composite, which will be used for the esterification catalyst and the optimization process for the esterification reaction is carried out using the response surface methodology (RSM) and experimental central composite design (CCD). Importantly, the observed independent variables were temperature, catalyst weight, and reaction time to produce fatty acid methyl ester (FAME) products. The catalyst was successfully synthesized, which was shown from the SEM characterization strengthened by the presence of a sulfate group in the FTIR results and the calculation results of high acidity properties. Optimization of FFA esterification with SCZ catalyst obtained optimal conditions with a temperature of 79oC, a catalyst weight of 3.00 g, and a reaction time of 134 minutes with a FAME product of 93.75%, considering that the viscosity of biodiesel is below that required by the API.

Singlet oxygen formation from photoexcited P3HT:PCBM films applied in oxidation reactions

Poly(3-hexylthiophene) thin films containing carbon-based nanostructures, i.e. fullerenes such as Buckminsterfullerene (C60) or phenyl-C61-butyric acid methyl ester (PCBM), or single-walled carbon nanotubes, were investigated as heterogeneous photosensitizers producing singlet oxygen...

GC-MS ANALYSIS PROFILE AND BIOACTIVE COMPONENTS OF FLOWERS OF Bergenia ciliata, A WEED OF ROCK CREVICES

Bergenia ciliata is a weed of hilly areas of Pakistan that generally grows in rock crevices. In the present study, flowers of this weeds were collected from Murree. The dried flowers were extracted in methanol and subjected to GC-MS analysis that showed 7 compounds in it. The predominant compound was hexanedioic acid, bis(2-ethylhexyl) ester (48.88%) followed by γ-sitosterol (22.56%). Moderately occurring compound was cyclohexane, 1,3,5-triphenyl- (12.87%). The remaining compounds namely n-hexadecanoic acid (4.97%), pentadecanoic acid, 14-methyl-, methyl ester (3.77%), 9,12-octadecadienoic acid, methyl ester, (Z,Z)- (2.94%) and 9,12,15-octadecatrienoic acid, methyl ester, (Z,Z,Z)- (2.92%) were categorized as less abundant compounds. Literature survey indicated that these compounds possess antimicrobial, larvicidal, anti-inflammatory, anticancer and/or antidiabetic properties.

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.

Modeling of optical characteristics of organic solar cells based on poly (3,4-ethylene dioxythiophene): polystyrene sulfonate with incorporated silver nanoparticles

Changing the geometric parameters of the elements of the organic solar cell (OSC) and its components, changes in its optical characteristics such as reflection, absorption and transmission of light were studied. In the simulation, the main elements influencing the change in the characteristics of the OSC were poly (3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS), poly (3-hexylthiophene): [6,6] phenyl-C61butyric acid methyl ester (P3HT: PCBM) on silver nanoparticles. The dimensions of silver nanoparticles coincide with the thickness of the PEDOT layer (50 nm) in which they are located, the particle diameter is 45 nm, the thickness of the P3HT: PCBM layer has always remained equal to 100 nm. The peak at a wavelength of about 726 nm, when there are silver particles in the OSC, indicates the presence of localized surface plasmon resonance (LPPR), which causes a local amplification of the electromagnetic field near the surface of metal nanoparticles. LPPR induced by silver nanoparticles not only increases the degree of light absorption, but also enhances the degree of exciton dissociation. As a result, photocurrent and overall OSC efficiency can be significantly improved due to LPPR.