ANTIOXIDANT ACTIVITY OF FOREST MANGGOSTEEN (Garcinia hombroniana Pierre) FRACTION USING DPPH AND ABTS METHOD

This study was carried out to determine the active antioxidant fraction of Garcinia hombroniana bark extract by the DPPH and ABTS method. Along with this, the study also attempts to identify the class of compounds present in the various extract of G. hombroniana by the active fraction. The bark extract of G. hombroniana was prepared by the multilevel maceration method by using three solvents including n-hexane, ethyl acetate, and 96% ethanol. Results of study suggested that n-hexane (HSE), ethyl acetate (EASE) and ethanol 96% extract (ESE) have antioxidant activity with IC50 value of 423 ± 16.72 μg/mL, 284.89 ± 2.7μg/mL, and 10.49 ± 0.19 μg/mL in DPPH assay, while these extracts showed IC50 value of 560.92 ± 48.86 μg/mL, 430.18 ± 16.65 μg/mL, and 13.92 ± 0.57 μg/mL respectively in ABTS assay. Further, fractionated using vacuum column chromatography revealed the presence of five fractions viz., A, B, C, D, and E. Among these, fractions D showed the highest antioxidant activity with an IC50 value of 4.83 ± 0.18 μg/mL and 6.82 ± 0.31 μg/mL in DPPH and ABTS assays. Results of the fractioned analysis and qualitative determination showed that the active fraction of G. hombroniana contained flavonoid, triterpenoid, alkaloid, and saponin compounds, and antioxidant activities of these extracts might be due to the presence of these active ingredients.

Antibacterial activity of secondary metabolites isolated from Ficus aurata (Miq.) fruits

This research aimed to isolate chemical constituents from ethyl acetate and n-hexane fractions of Ficus aurata (Miq.) fruits and investigated their antibacterial activities. Chemical constituents were separated by using vacuum column chromatography, gravity column chromatography, and thin layer chromatography. The structures of the isolated compounds 3,4-dihydroxybenzoic acid (1) and β-sitosterol (2) were elucidated using various spectroscopic methods, including UV, IR, and NMR (1H-NMR, 13C-NMR, and DEPT). While, antibacterial activity was done by assay using Resazurin Microtiter Assay method. These 2 compounds reported as new constituents from F. aurata fruit. In addition, analysis of the bioassay showed that compound 1 had a notable antibacterial activity against gram negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATTC 27853), and gram-positive bacteria (Staphylococcus aureusATCC 23235) with the Minimum Inhibitory Concentration (MIC) value of 0.1563 µg/mL, and it indicated the same MIC as cefadroxil (positive control). Compound 2 has weak antibacterial activity compared to cefadroxil (positive control). The results found that Ficus aurata (Miq.) fruits metabolites have antibacterial activity and show potency as antibacterial agent. Different kinds of bacteria and assay could be needed to investigate and support its antibacterial activity in the future.

Development of Technological Schemes for Increasing the Selection of Vacuum Gas Oil

The analysis of the operation of the vacuum columns of the ELOU AVT units showed that in a number of cases the half-gas contains up to 30% of vacuum gas oil with a boiling point of up to 560 ° C. A comparative analysis of three options for deepening the selection of heavy vacuum gas oil during the distillation of fuel oil has been carried out. A traditional scheme with a pressure reduction at the top of the vacuum column, the rectification of a half-sludge without heating it after the main vacuum column in an additional its subsequent rectification in the second column, with the selection of heavy vacuum gas oil. The analysis of the operation of the vacuum column of the vacuum rectification unit ELOU AVT-6 was carried out. The process was simulated in the environment of the software product Aspen HYSYS, the possibility of increasing the selection of heavy vacuum gas oil in the process of deep vacuum rectification of tar was theoretically proved. The advantages and disadvantages of two-column vacuum distillation of fuel oil are considered. Structural design of the rectification column and raw material input device is proposed.

Antibacterial Activity And Phytochemical Screening From Chromatography Fraction Of Ethanol Extract Of Sarang Banua (Clerodendrum fragrans Vent Willd) Against Salmonella enterica

Ethanol extract of sarang banua leaves (Clerodendrum fragrans) has biological activity. This study aims to isolate the fraction of ethanol extracts of Sarang Banua leaves (Clerodendrum fragrans) and test their antibacterial activity against Salmonella enterica. The isolation method uses the vacuum liquid chromatography method, with eluent n-hexane, ethyl acetate and methanol with increasing polarity levels. Antibacterial activity was carried out by the inhibitory test, the MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration). The results showed that the FC fraction chromatographic results of the vacuum column of ethanol extract of Sarang Banua leaf (Clerodendrum fragrans) had antibacterial activity against Salmonella enteric with a strong inhibitory power (inhibitory zone 18.25 mm), MIC value of 125 µg / mL and MBC value of 125 µg / mL are included in the medium category. Inhibition, MIC and MBC values of chloramphenicol (positive control) against S. enterica were 17.40 mm; 31.2 μg / mL and 62.5 μg / mL. In the FC fraction there are higher amounts of secondary metabolites flavonoids, tannins, as well as small amounts of alkaloids, saponin, steroids & triterprnoids.

Influence of the Water Nature on the Two-phase Flow in an Air-lift Column

The aim of this study is to determine the phase indicator functions of a two-phase flow in an air-lift vacuum column. The outcome of this study is to master the hydrodynamics in a vertical column when determining the size, the velocities of the bubbles and the void rate then the gas-liquid interphase. The functions are the vacuum rate, the interface speed and bubble size, the flow rate and the speed of the liquid phase. The vacuum lift air column that is the subject of this study is based on the principle of air lift and flotation, all under vacuum. In its operation, the column combines hydraulic pumping, solute transfer and particle phase separation functions, which has the particularity of minimizing energy costs. The process of air-lift columns under the vacuum is still at the development stage and the experimental study of its hydrodynamics is one of the determining axes in the course of the exploration with a assessment to optimizing its design and functioning. The experiments were carried out on a vertical column composed of two concentric plexiglas tubes connected to a water recirculation tank and to a vacuum pump. For all experiments performed, demineralized water and salt water are used and the flow rate is measured using a flow meter. The experimental analysis is done using two-phase instrumentation consisting of a bi-probe and the use of experimental techniques has enabled a better understanding of the hydrodynamics of the two-phase flow.

Isolation of terpenoid compound of n-hexane extract of Marsilea crenata Presl..

Isolation, identification, and structure elucidation of terpenoid compounds from an n-hexane extract of Marsilea crenata Presl., had been done. The leaves of M. crenata was extracted using n-hexane solvent. The extract then separated with vacuum column chromatography and open column chromatography to obtain the isolate. Furthermore, the isolate was identified and elucidated using UV-Vis, FT-IR, 1H-NMR, 13C- NMR, and 2D-NMR (COSY, HMQC, and HMBC). The identification and elucidation of the isolated structure from an n-hexane extract of M. crenata leaves indicate the isolate was a pentacyclic triterpenoid.

α-Glucosidase Inhibitory Activity Of Cucurbitane Derivate Isolated From Methanol Extract Of Momordica charantia L. Leaves

Cucurbitane derivative has been isolated from methanol extract of the leaves of bitter melon (Momordica charantia). Purification of methanol extract using vacuum column chromatography method using n-hexane: ethyl acetate as the mobile phase was obtained a white powder isolate. This isolate was elucidated to obtain chemical structures based on spectroscopic data (FT-NMR, FT-IR, and LC-MS/MS) and resulted a cucurbitane derivate, namely momordicine I. The MeOH extract and the isolate were evaluated for α-glucosidase inhibitory effect. Both MeOH extract and momordicine I showed moderate activities with %inhibition 27.34% and 15.79 % at 100 µg/mL repectively.

Repair and FFS of Vacuum Column for Corrosion Under Insulation

One of the vacuum column made of Carbon steel (SA 285 Gr. C) was found with severe corrosion under insulation during turnaround inspection. The equipment was in service for the past 46 years. The corrosion was around the full circumference of the column at a location immediately above the stiffener ring. The wall loss was extensive, which mandated a welded full circumferential patch to encapsulate the corroded region. A full circumferential lap patch with reinforcement plug welds was designed as per ASME PCC-2 [2], fabricated and installed at site. During the dye penetrant examination of the patch plate welds, fine cracks were noted at the toe of the fillet welds. A subsequent PAUT (Phased Array Ultrasonic Testing) of patch plate welds, showed that the cracks were in column shell (base material) surface initiating from toe of the fillet weld of the patch and beneath the fillet weld. The cracks found in first few sections of welds were ground and re-welded with appropriate pre-heating and post-heating. However, some cracks were still observed in base material, although with reduced magnitude compared to previous welding. Despite proper controls in place during the welding, the challenge was, some minor cracks were re-occurring at the base material surface below fillet welds. A multi discipline review was carried out to understand the potential root cause for the cracks, detailed assessment of risks and impact due to the cracks. A risk based approach was followed, in evaluating cracks for acceptance based on API 579-1/ASME FFS-1 [1], for continued service of the column and to minimise the extension of turn around duration. Later, a long-term plan was made to replace the equipment.