Vacuum Column Research Articles

How innovations in methodology offer new prospects for volume electron microscopy

Detailed knowledge of biological structure has been key in understanding biology at several levels of organisation, from organs to cells and proteins. Volume electron microscopy (volume EM) provides high resolution 3D structural information about tissues on the nanometre scale. However, the throughput rate of conventional electron microscopes has limited the volume size and number of samples that can be imaged. Recent improvements in methodology are currently driving a revolution in volume EM, making possible the structural imaging of whole organs and small organisms. In turn, these recent developments in image acquisition have created or stressed bottlenecks in other parts of the pipeline, like sample preparation, image analysis and data management. While the progress in image analysis is stunning due to the advent of automatic segmentation and server‐based annotation tools, several challenges remain. Here we discuss recent trends in volume EM, emerging methods for increasing throughput and implications for sample preparation, image analysis and data management.

Rapid Isolation of Plant Essential Oil Components by Small-Scale Dry Column Vacuum Chromatography: An Experiment Combining Natural Product Isolation and Antibacterial Testing

Rapid Isolation of Plant Essential Oil Components by Small-Scale Dry Column Vacuum Chromatography: An Experiment Combining Natural Product Isolation and Antibacterial Testing

Novel design of lubricant-type vacuum distillation process for lube base oils production from hydrocracking tail oil

Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.

Antibacterial, antioxidant and cytotoxic activities of the stem bark of Archidendron jiringa (Jack) I.C. Nielsen

Abstract Archidendron jiringa (Jack) I.C. Nielsen plant, locally known as jengkol, is a species belongs to Archidendron genus of the Fabaceae family. This plant is a potential source of biologically active secondary metabolites, which are useful for various purposes, such as to destroy bacteria and fungi, to treat cancer, and as antioxidant agent. In this study, extract of A. jiringa stem bark was fractionated and subsequently tested for antibacterial, cytotoxic and antioxidant activity. Extraction was carried out using maceration and fractionation of the extract was conducted using both vacuum liquid and column chromatography techniques to obtain three fractions. The biological activity of the bulk extract and fractions were then evaluated using disc diffusion method, revealing that the sample with the highest activity against Bacillus subtilis and Escherichia coli is the ethyl acetate extract, while no inhibitory effect on both bacteria was observed for some ethyl acetate fractions tested. The screening tests indicate that the bulk extract and all fractions exhibit promising toxicity, with the LC50 values in the range of 227–837 ppm. In addition, good antioxidant activities, with the IC50 values in the range of 0.7–7.2 ppm, are displayed by bulk extract and the fractions.

Experimental study on remediation of low permeability Cu–Zn contaminated clay by vacuum enhanced leaching combined with EDTA and hydrochloric acid

To improve the washing efficiency for low permeable clay, the method of vacuum enhanced washing technology was proposed. In this study, ethylene diamine tetraacetic acid (EDTA) and hydrochloric acid (HCl) as eluents, the experiments of remediation of Cu–Zn contaminated cohesive soil by traditional soil column leaching and vacuum enhanced leaching was carried out. Results show that compared with traditional leaching method, the vacuum enhanced leaching method can significantly shorten the leaching time and prominently improve the removal rate of heavy metals Cu–Zn. When concentration of EDTA is 0.1 mol/L, the removal rate of Cu–Zn can reach 95.7% and 82.9%, respectively by vacuum-enhanced leaching. When concentration of HCl is 0.2 mol/L, the removal rate of Cu–Zn by vacuum enhanced leaching method can reach 96.2% and 90.2%, respectively. Whereas, the higher the concentration of EDTA and HCl, the slower the leaching rate. At the same concentration, the leaching rate of HCl was faster. After HCl leaching, the soil structure was seriously corroded, and the relative content of mineral composition changed considerably. After EDTA leaching, the corrosion of soil structure is light, and the relative content of mineral composition changes little. The conclusions obtained are of crucial theoretical value and technical support for environmental engineering.

Optimization and simulation of refinery vacuum column with an overhead condenser

Production of clean energy is the major concern for several process industries in recent times such as oil, gas, and petrochemical, however prices are persisted to rise and the optimization of energy in the process industries are keen important. The convectional methods such as distillation column with high energy consumption have been used to convert value added products from crude. Due to frequently uses of the distillation, it is recommended that it should be optimized and utilized efficiently. For the better utilization, it is required to alter the convectional methodology. The new changes can reduce the energy utilization and improve some of consumed energy. In the present paper, investigation on the energy optimization in overhead condenser of a vacuum column of petroleum using cooled water Using Chemcad 5.1 software has been studied. For energy optimization, feed temperature was altered to a suitable temperature (25 °C, 15 °C and 5 °C) for condensation of overhead steam distillation. It is expected that the quality of the hydrocarbon vapors in the overhead condenser outlet would reduce; thereby decreasing the load on the ejector. As per the principle of ejector operation, this would decrease the vacuum column pressure. With reduction in the column pressure, it is expected to introduce the feed at a lower temperature and still operate the column at the same efficiency. It will lower down the burden of energy requirements. This implies reduction in the refinery operating cost. In the next step, the comparison of the three cases, and finally evaluating the overall energy economics were carried out. The main feed was used as a cold fluid in the heat exchanger before the transfer to the main condenser. The result of this study shows that, 1.2532 E+10 cal/hr of energy was required using inleat water temperature of 50 °C in overhead condenser.

Efficacy of Merremia mammosa Hall Terpenoid Fraction againts Mycobacterium tuberculosis

Tuberculosis is still a pandemic disease in Indonesia. People in Madura Island, Indonesia, usually use the rhizome of Merremia mammosa Hall as anti-tuberculosis. In this study, the antibacterial activity of terpenoid fractions of Merremia mammosa rhizome against Mycobacterium tuberculosis has been studied using agar dilution method at a concentration of 200-25 µg/mL, incubated for 21 days in 7H10 Midlebrook medium. N-hexane extract of Merremia mammosa has been fractionated using ethyl acetate. The ethyl acetate fraction was subjected to vacuum column chromatography using gradient concentration of ethyl acetate-n hexane, and obtained 11 subfractions. There were two subfractions indicated the presence of terpenoid compounds. These subfractions were grouped and subjected to antimicrobial assay. Result showed that the terpenoid compounds have antituberculosis property with minimum inhibition concentration (MIC) value of 100µg/mL. The result was supported by acid -fast Zielh-neelsen stain, which indicated that at a concentration of 100 and 200 µg/ml of the subfractions, there were no growth of Mycobacterium tuberculosis visually detected. In conclusion, Merremia mammosa is potential to be developed as antituberculosis agent. The chemical compounds responsible for this activity are currently under investigation for further study.

Cytotoxic Activity of Peronema canescens Jack Leaves on Human Cells: HT-29 and Primary Adenocarcinoma Colon Cancer

Background: In Indonesia, this species was well known in Sumatera, Kalimantan, Java, and Sulawesi. Peronema canescens Jack (Sungkai) was traditionally used as an anti-flatulent, fever, toothache. Sungkai leaves contain many secondary metabolites with potential anticancer activity. The reported anticancer research was still limited to the cytotoxic activity of chloroform extract on the HT-29 colon cancer cell line. However, it was necessary to uncover the underlying mechanism. Aim: The purpose of this study was to investigate the mechanism (such as cell cycle inhibition, induces cells apoptosis, and necrosis) of subfraction chloroform (SF3) from P. canescens extract has anticancer activity on HT-29 cells and primary Adenocarcinoma (AdenoCa pT3N1cM1) colon cancer cells. Materials and Methods: The extraction by maceration method using methanol solvent, the fractionation process was using vacuum column chromatography (VCC) with polarity gradient eluent. The cytotoxicity of SF3 was measured by MTT assay. The cell cycle inhibition, apoptosis induction, and necrosis cells were evaluated with the Flow cytometry method. Results: Cytotoxicity value (IC50) against AdenoCa cells was 1.897 μg/ml. The inhibition activity of synthesis and mitosis phase in cell cycle demonstrated that the different concentrations of SF3 have inhibition activity on HT-29 (29.614 μg/ml) of 26.79% and 0.16%, AdenoCa cells (14.807 μg/ml) of 10.27% and 19.29%, respectively. For induced apoptosis activity on HT-29 (29.614 μg/ml) and AdenoCa cells (14.807 μg/ml) were 26.58% and 11.50%, successively. Whereas, necrosis activity on HT-29 (29.614 μg/ ml) and AdenoCa cells (14.807 μg/ml) were 0.02%, and 9.56%, respectively. Conclusion: The subfractions chloroform (SF3) of P. canescens extract has potential activity on HT-29 and Adenocarcinoma cells through cell cycle inhibition, induces apoptosis and necrosis cells.

Mini-Refinery Vacuum Unit: Functional Analysis and Improvement of Vacuum Overhead System

The purpose of this study was to analyze the functioning of the vacuum distillation unit of a mini-refinery and to develop recommendations for improving the vacuum overhead system with the aim to reduce the cost of creating and maintaining a vacuum in the fuel oil separation column. A calculation model of the vacuum unit was developed in the Unisim Design R451 software package, which was identified by comparing the calculated data with the data from an industrial study for two operating modes of the installation. Replacing the existing steam-ejector pump with a liquid-ring vacuum pump was proposed. A numerical experiment was carried out on the developed model, the purpose of which was to determine the “bottlenecks” of the scheme. The peculiarity of the experiment was that the vacuum column and the vacuum overhead system were considered as a single whole. As a result, it was determined that the “bottleneck” is the condenser, which was proposed to be replaced. During the technical and economic analysis, two possible vacuum overhead system schemes were considered; according to the results, it was determined that the vacuum overhead system scheme based on a liquid-ring vacuum pump will help reduce operating costs by 78%.

Bioassay-guided isolation of cytotoxic constituents of Aframomum melegueta K.Schum. seeds

The seeds of Aframomum melegueta are used extensively in the Nigerian ethnomedicine for the management of cancer. This study therefore aimed at isolating and characterizing its cytotoxic constituents. Methanol extract of the seed was obtained through cold maceration, and it was further partitioned into n – hexane, dichloromethane and ethylacetate. The most active fraction was purified on repeated chromatographic techniques, using vacuum liquid chromatography (VLC), column (CC), and high-performance liquid chromatography (HPLC). The extract, purified fractions and isolated compounds were tested for their cytotoxic activities against the human Rhabdomyosarcoma (RD) and breast (MCF-7) cancer cell lines, using MTT assay. The crude extract and n-hexane fraction were found to be selectively cytotoxic to the cancer cell lines. Bioassay-guided fractionation of the n-hexane fraction led to the isolation of three compounds, which were identified as 6-shogaoal, 6-paradol, and 1-dehydro-6-gingerdione. 6-shogaoal demonstrated the highest cytotoxicity with CC50 values of 0.11 ± 0.02 and 0.25 ± 0.05ìg/mL against RD and MCF-7 cell lines respectively, and these were higher in activity when compared with cyclophosphamide (CC50 = 1.98 ± 0.15 and 0.71 ± 0.7ìg/mL). The presented data validates the ethnomedicinal use of A. melegueta in the treatment of cancer and is also indicative of the potential of 6-shogaol as an anticancer agent.

A Sesquiterpene Aldehyde Isolated From Ethyl Acetate Extract of Lansium Domesticum Fruit Peel

Lansium domesticum (fam. Meliaceae) contains various compounds with various biological activities. Based on the previous research, extracts from several parts of the plant have biological activity. This study aimed to isolate a compound from the fruitpeel of L. domesticum and evaluate cytotoxic activity against T47D, WiDr and HepG2 cell lines. Powdered peels were macerated with ethyl acetate and the filtrate was evaporated to give EtOAc extract. Dried extract was triturated with n-hexane to give n-hexane soluble fraction (A) and insoluble fraction (B). The fraction B was separated using vacuum column chromatography (VLC) with mobile phase n-hexane: ethyl acetate and given 5 fractions. Fractions B3-B5 were combined and separated using VLC with n-hexane and ethyl acetate as mobile phase. This VLC separation gave 18 subractions, subfractions 6-9 with the similar TLC profile were combined. This subfraction was separated further using preparative thin layer chromatography to give compound 1. The Isolated compound (1) appeared as liquid. The chemical structure of 1 was identified acoording to spectroscopic data and comparison with literature. Cytotoxic bioassay was performed on T-47D, WiDr and Hep G2 cell lines in a series of concentrations at 50, 40, 30, 20, 10 and 5µg/mL, with Doxorubicine used as positive control. According to spectroscopic data, compound 1 was identified as 2-ethyl,3-(1’-hydroxy-2’-menthene) propenal, and demonstrate the strongest cytotoxicity against T-47D cell lines (IC50=39.18+1.54 µg/mL).

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.

DAMAGING PROCESS FOR COILS OF FIRED HEATERS DUE TO PHASE SEPARATION OF HEATED PRODUCT

During the operation of heating tube furnaces with fire heating, in some cases, damage to the base metal and welded joints of the coils occurs, which carries the risk of leakage the combustible product and fire. So far, no calculated justification has been given for the occurrence of damage to the base metal and welded joints of the furnace coils in the form of cracking. As a rule, corrosion cracking from exposure to various heated products or errors of technical personnel is suggested as a damage mechanism. Limiting the damage mechanisms under consideration does not make it possible to develop effective damage prevention measures. The actual problem is the calculation justification of the occurrence of damage, the subject of which is this article. For reliability, the consideration is carried out on the example of a tubular furnace for creating a hot jet in the vacuum column of the CDU. During the 4th year of operation, the base metal of the output pipe of the coil on the furnace coil was burned through. The article suggests the mechanism of damage to the furnace coils due to the process of separation of the vapor-liquid mixture in horizontal pipes. Since the coefficient of heat transfer from the pipe wall to the gas phase is much lower compared to the liquid phase, the heat transfer in the upper part of the pipe is difficult, which causes an increased temperature of the pipe wall and a temperature difference between the upper and lower parts of the pipe. The presentation is illustrated by the results of thermal imaging inspection of the furnace and inspection of the damaged pipe. A model of the formation of internal forces due to the tightness of temperature deformations under conditions of temperature differences is considered. The article presents and solves the problem of the stress-strain state of the metal in the event of additional loads due to the formation of a temperature difference due to the phenomenon of phase separation of the heated product in horizontal pipes. The calculated study indicates the types and places of pipe damage caused by the phenomenon of phase separation of the heated product, the results of the study are confirmed by the operating data.

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.

Fractions and isolated compounds from Lansium domesticum fruit peel exhibited cytotoxic activity against T-47D and HepG2 cell lines

Abstract. Fadhilah K, Wahyuono S, Astuti P. 2021. Fractions and isolated compounds from Lansium domesticum fruit peel exhibited cytotoxic activity against T-47D and HepG2 cell lines. Biodiversitas 22: 3743-3748. Lansium domesticum (Fam. Meliaceae), a tropical fruit (local name, Duku), has been reported to have various biological activities. At the moment we emphasize on searching compounds to have cytotoxic activity from the peel of L. domesticum. The study was initiated by extraction with EtOAc followed by fractionation that was monitored by thin-layer chromatography (TLC) and cytotoxicity against T-47D and HepG2 cells. The EtOAc extract of the sample was triturated with n-hexane to give n-hexane soluble (A) n-hexane insoluble fractions (B). The B fraction was fractionated by vacuum column chromatography using gradient solvent composition of n-hexane: acetone to give 18 fractions. According to TLC similarity pictures, fractions were combined to give 6 fractions (I-VI). Isolation was performed using preparative TLC, and the cytotoxic assay was performed using MTT method. The isolated compound was identified as a sesquiterpene having one aldehyde functional group, based on spectroscopic data.The isolated compound displayed cytotoxic activity on T-47D (IC50, 48.58 + 0.96 µg/mL) and HepG2 (IC50, 127.45 + 25.76 µg/mL).

Identifikasi Senyawa Terpenoid dan Steroid pada Beberapa Tanaman Menggunakan Pelarut N-Heksan

Hexane is a hydrocarbon compound of alkanes with the chemical formula C6H14. The prefix hex refers to the six carbon atoms found in the hexane and the suffix ana is derived from the word alkane which refers to the single bond connecting the carbon atoms. Identification of terpenoid compounds and steroids has been identified in several plants, namely Red Shoots (Syzygium myrtifolium Walp.), Salam (Syzygium polyanthum), bilaran Tapah (Argyreia nervosa (Burm. F.), Blind (Excoecaria agallocha L.), as well as on the lotion preparations Citrus hystrix DC. This study was conducted to determine the content of terpenoid compounds and steroids found in some parts of plants using n-hexane solvents. Research used is qualitative research with Lieberman Burchard method. Review this article using a method of literature study by searching sources and literature with data form in the form of national journals to international journals about the last 10 years (2012-2021). Identification is carried out on extracts, fractions, isolates and lotion preparations using liquid vacuum chromatography, column chromatography, thin-layer chromatography, and Lieberman-Burchard reagents. The results showed that all of the samples were positive for terpenoid compounds and steroids using n-hexane solvents.

Isolation flavonoid compound chrysoeriol from ethyl acetate extract of zaitun leaves (Olea europaea)

The Olive Tree (Olea europaea) is a plant originating in the Middle East. Olea Europaea plant is contained several secondary metabolites such as olive oil, phenolic compounds, flavonoids, triterpen, biphenol. The aims of this research are to isolate and identify a flavonoid compound that extracted in the ethyl acetate of olive leaves. Isolation was carried out by meseration, liquid vacuum chromatography, column chromatography and thin layer chromatography. Isolation results obtained 10 mg isolates were identified using proton nuclear magnetic spectroscopy (1H-NMR) and carbon (13C-NMR). According to spectra analysis, describe that isolate is chrysoeriol.

Разработка технологических схем по увеличению отбора вакуумного газойля

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.

A New Triterpene Glycoside from Pinus pumila

In the current work, a novel triterpene saponin, named ursolic acid 3-O-[α-L-rhamnopyranosyl(1"→6')]-β-D-glucopyranosyl-28-O-β-D-glucuronopyranoside (1), together with two known flavonol glycosides, kaemferol 3-O-α-L-rhamnopyranoside (2) and quercetin 3-O-β-D-glucopyranoside (3), was isolated from the stem outer barks of Pinus pumila by repeated column chromatography and vacuum liquid chromatography. The chemical structures of the secondary metabolites 1–3 were characterized by their spectroscopic data and other physico-chemical evidence, as well as by comparison with the literature. The secondary metabolites 2 and 3 were found in this species for the first time.

Isolasi dan Uji Aktivitas Antioksidan Ekstrak Metanol Dari Buah Senduduk Bulu (Clidemia hirta (L.) D. Don)

A study on isolation and antioxidant activity of secondary metabolit of methanol extract of fruit of Senduduk Bulu (Clidemia hirta (L.) D. Don) has been carried out. Senduduk bulu is used for folk medicine to many diseases. Flavonoid and phenolic has been reported to its activity as antioxidant. The aim of this research was to find antioxidant compound and antioxidant activity of this fruit. Isolation works were conducted using Vacuum Liquid Chromatography and Column Chromatography method. Antioxidant activity was determined using DPPH free radical scavenging methods. The isolation works afforded 10 mg of pure compound CHP1 which was obtained as white crystal, with its melting point of 165–167ºC, soluble in chloroform and slightly soluble in methanol. This compound gave positive reaction with Liebermann-Burchard (LB) reagent and concluded as terpenoid. Based on it UV spectrum, this compound showed a λ max of 316 nm. Its FT-IR spectrum showed appearence of some functional groups of OH, C-H aliphatic, C=O ester,C=C alkene, CH bending and C-O. The 1H-NMR spectrum showed the alkene protons and methyl protons which is a characteristic of terpenoid compounds. The pure compound (CHP1) provided a weak antioxidant activity with the IC50 of 327,01µg/mL.