Gas Chromatography-mass Spectrum Analysis Research Articles

Optimization, Production, and characterization of cottonseed methyl ester based on Box-Behnken in response surface design and gas Chromatography-Mass spectrum analysis

Renewable energy sources have a significant approach to eco-friendly systems with economically cost-effective and efficient use of biodiesel. The creation of innovative catalysts is attracting the attention and concern of the chemical and manufacturing sectors to be used in the production of biodiesel. The main objective of this work is to produce the optimum biodiesel yield using BBD design and the base-catalyzed method. The production of biodiesel was achieved through experimental investigation (alkali-catalyzed transesterification) and optimized using the BBD design method.The most important parameters such as methanol to oil ratios, KOH as catalysts, and reaction times were provided with variable conditions. The variation of methanol to oil ratios has significant relationships and is highly correlated in findings. The physicochemical properties of cottonseed biodiesel were carried out according to ASTM and EN standards. The maximum yield was achieved at 96.708 at a molar ratio of 6:1, reaction time of 60 min, and catalyst concentration of 1 wt%. The strong correlation between actual and predicted values of COSME was analyzed using ANOVA variances. The F-value and P-value validated the outcomes of produced biodiesel having a model value of 43.68 and 0.00, respectively. The coefficient of determinations and adjusted R2 of CSOME were achieved at 98.7% and 98.6%, respectively. The gas chromatogram mass spectrum analysis was also obtained to identify the acid profile present in COSME. The major percentage of ester available in COSME has been determined using GC–MS analysis and presented by its weight percentages. The main esters have been including myristic acid methyl ester (1.7%), palmitic acid methyl ester (26.65%), methyl 9-cis,11-trans-octadecadienoate(44.05%), ethyl 9. Cis.11.trans octadecadienoate(9.67%), methyl 20-methyl-heneicosanoate(6.83%), 9,12-Octadecadienoic acid (Z,Z)-, 2-hydroxy-1-(hydroxymethyl)ethyl ester(1.93%), and Pentacosanoic acid, methyl ester(7.14%).

Caralluma pauciflora based Ag-NPs activate ROS - induced apoptosis through down-regulation of AKT, mTOR and pI3K signaling in human gastric cancer (AGS) cells

The phytochemicals found in Caralluma pauciflora were studied for their ability to reduce silver nitrate in order to synthesise silver nanoparticles (AgNPs) and characterise their size and crystal structure. Thunbergol, 1,1,6-trimethyl-3-methylene-2-(3,6,9,13-tetram, Methyl nonadecanoate, Methyl cis-13,16-Docosadienate, and (1R,4aR,5S)-5-[(E)-5-Hydroxy-3-methylpent were the major compounds identified in the methanol extract by gas chromatography–mass spectrum analysis. UV/Vis spectra, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscope with Energy Dispersive X‐ray Analysis (EDAX), Dynamic Light Scattering (DLS) particle size analyser and atomic force microscope (AfM) were used to characterise the Caralluma pauciflora plant extract-based AgNPs. The crystal structure and estimated size of the AgNPs ranged from 20.2 to 43 nm, according to the characterization data. The anti-cancer activity of silver nanoparticles (AgNPs) synthesised from Caralluma pauciflora extract. The AgNPs inhibited more than 60% of the AGS cell lines and had an IC50 value of 10.9640.318 g, according to the findings. The cells were further examined using fluorescence microscopy, which revealed that the AgNPs triggered apoptosis in the cells. Furthermore, the researchers looked at the levels of reactive oxygen species (ROS) in cells treated with AgNPs and discovered that the existence of ROS was indicated by green fluorescence. Finally, apoptotic gene mRNA expression analysis revealed that three target proteins (AKT, mTOR, and pI3K) were downregulated following AgNP therapy. Overall, the findings imply that AgNPs synthesised from Caralluma pauciflora extract could be used to treat human gastric cancer.

Phytochemical Composition, Antioxidant, Antimicrobial, Antibiofilm, and Antiquorum Sensing Potential of Methanol Extract and Essential Oil from Acanthus polystachyus Delile (Acanthaceae).

The evolution of microbes in response to conventional antimicrobials leads to antimicrobial resistance (AMR) and multidrug resistance (MDR), and it is a global threat to public health. Natural products are possible solutions to this massive challenge. In this study, the potential of Acanthus polystachyus extracts was investigated for phytochemical composition and biological properties as antimicrobials. Gas chromatography-mass spectra (GC-MS) analysis of methanol extract (ME) and essential oil (EO) detected 79 and 20 compounds, respectively. The major compounds identified in ME and their abundance were β-sitosterol acetate (16.06%), cholest-5-en-3-yl (9Z)-9-octadecenoate (9.54%), 1-dodecanol (7.57%), (S)-(E)-(-)-4-acetoxy-1-phenyl-2-dodecen-1-one (6.03%), neophytadiene (5.7%), (E)-2-nonadecene (3.9%), hexanol-4-D2 (2.92%), and decane (2.4%). Most compounds have known bioactive functions. In EO, the major compounds were stearyl alcohol (25.38%); cis-9-tetradecenoic acid, isobutyl ester (22.95%); butyl 9-tetradecenoate (10.62%); 11,13-dimethyl-12-tetradecen-1-ol acetate (10.14%); ginsenol (3.48%); and diisooctyl phthalate (2.54%). All compounds are known to be bioactive. The antioxidant activity of ME and EO ranged from 48.3 to 84.2% radical scavenging activity (RSA) and 45.6 to 82% RSA, respectively, with dose dependency. The disc diffusion assay for the antimicrobial activity of ME revealed high inhibition against Acenetobacter baumannii (130.2%), Pseudomonas aeruginosa (100.3%), and Staphylococcus aureus (87.7%). The MIC, MBC/MFC, and MBIC values for ME were 0.5-1.0, 2-4, and 0.5-1.0 mg/mL and for EO were 0.31-0.62, 1.25-2.5, and 0.31-0.62 μL/mL, respectively, indicating inhibition potential as well as inhibition of biofilm formation. The tolerance test values indicated bactericidal activity against most strains and bacteriostatic/fungistatic activity against A. baumannii, E. faecalis, and C. albicans. The antiquorum sensing activity of ME achieved by pyocyanin inhibition assay on P. aeruginosa showed a 51.6% inhibition at 500 μg/mL. These results suggest that ME and EO derived from A. polystachyus leaves are potent, valuable, cost-effective antioxidants and antimicrobials. Both extracts may effectively combat pathogenic and resistant microbes.

Evaluation of Antibacterial and Antibiofilm Activity of Cucurbita Maxima Leaf Extract Against Streptococcus Mutans Isolated from Orthodontic Patients

Aim The aim of this investigation was to evaluate the antimicrobial activity and anti-biofilm activity of Cucurbita Maxima leaf extract on Streptococcus mutans isolated from dental plaque of subjects undergoing orthodontic treatment. Methodology Dental plaque samples were collected from out patients undergoing orthodontic treatment. From the plaque samples Biochemical Characterisation of Streptococcus mutans then Collection of Medicinal Plants was done followed by Preparation of Solvent Extract and stock Solution. Evaluation of Minimum Inhibitory Concentration (MIC) of the plant extract and Biofilm Inhibition Assay with Gas Chromatography-Mass Spectrum Analysis (GCMS) was carried out. Results The MIC was identified to be 1.25mg/ml. The biofilm inhibition assay showed that the extract did not inhibit the formation of the biofilm. The GCMS analysis identified twenty five constituent compounds from the crude extract.  Conclusion  The C. maxima leaf extract showed antibacterial activity against S. mutans and the minimum inhibitory concentration was identified at 1.25mg/ml. The extract did not inhibit the formation of biofilm. 

Chemical analysis of novel ginger and Hibiscus sabdariffa bio-preserved tomato powder

Background: Tomatoes (Solanum lycopersicum L.) are widely consumed vegetables globally,  and are well known for their nutrients and economic value.  This research aimed to create a tomato powder with improved nutraceutical benefits based on its ingredients. Methods: Fresh tomatoes, ginger, and dried hibiscus calyx were obtained and dehydrated at 45°C for 10 hours, 8 hours, and 1 hour and 30 minutes respectively. Proximate, elemental, phytochemical, high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrum (GCMS) analysis of the tomato powder mix were determined using standard methods.Results:  The proximate analysis revealed constituents of carbohydrates, fats, proteins, ash, fiber, and moisture as 65, 5, 10, 1, 7, and 12 % respectively. The GCMS also revealed 36 classes of compounds with different retention times. The most prominent peak is oleic acid with an RT value of 20.9.  The fiber content of the tomato powder mix was higher than what is obtainable in fresh tomatoes. Bioactive compounds like stigmasterol (5.25%), oleic acids (49.11%), n-hexadecenoic acid (26.58%), campesterol (2.72%), and octadecanoic acid (6.8%) are notably present with lycopene (135.745 mg/100 grams). Conclusion:The tomato powder mix is nutrient-packed and non-toxic. The bioactive components are known as antioxidant, anti-inflammatory, cardiovascular health enhancers, etc showing the possible use of the powder as a functional food.Keywords: Tomatoes powder, bioactive compounds, functional foods, dehydration

Biodiesel production from a novel renewable source through the ultrasound-assisted transesterification process, using energy efficient nanocatalyst developed from waste material

The depletion of fossil fuels created a thrust for an alternative renewable energy source, which could involve sustainable energy formation and cost-reducing catalysts. The catalyst derived from the waste material, specifically a heterogenous nanocatalyst, could economically add value to the process. In this study, a novel microbial strain, Rhodotorula mucilaginosa strain SML (RM-SML), was used as a source of oil for biodiesel production. The nanocatalyst developed from the Central Avian Research Institute – Broiler (CARIB) breed eggshell was used as a catalyst for transesterification, increasing the sustainability and economic viability of the process. RM-SML yielded 68.79 % of oil to its total dry cell biomass. The calcium carbonate-rich CARIB breed eggshell was calcinated in this study to synthesize a highly dynamic heterogeneous CARIB breed eggshell nanocatalyst (CBESNC). The calcination process parameters involved in the nanocatalyst synthesis were optimized using response surface methodology, yielding a maximum calcium oxide of 38.827 %. The synthesized CBESNC was characterized for its size by scanning electron microscopy imaging and its crystallographic nature by X-ray diffraction analysis. CBESNC was used as a heterogeneous catalyst in the ultrasonic-assisted transesterification of RM-SML bio-oil. The effect of the CBESNC in RM-SML bio-oil transesterification was studied and optimized using the response surface methodology, which yielded a maximum biodiesel conversion of 98.33 %. The prediction model in optimization studies was found to fit with the process and was validated experimentally. RM-SML biodiesel was studied for its physicochemical properties and found to meet American Society for Testing and Materials biodiesel standards. It was further confirmed with Gas Chromatography-Mass Spectrum analysis. The energy analysis results proved the commercialization feasibility of the study.

Unraveling the Variability of Essential Oil Composition in Different Accessions of Bunium persicum Collected from Different Temperate Micro-Climates

The present investigation was performed to evaluate the variability of the essential oil composition present in the seed extract of Kala zeera (Bunium persicum Bioss.) obtained from different geographical zones of Northwestern-Himalayan using Gas Chromatography-Mass Spectrum (GC-MS). The results of the GC-MS analysis revealed significant differences in the essential oil content. Significant variability was observed in the chemical constituents of the essential oils mainly for p-cymene, D-limonene, Gamma-terpinene, Cumic aldehyde and 1, 4-p-menthadien-7-al. Among these compounds, the highest average percentage across the locations was observed for gamma-terpinene (32.08%) which was followed by cumic aldehyde (25.07%), and 1, 4-p-menthadien-7-al (15.45%). Principal component analysis (PCA) also grouped the 4 highly significant compounds i.e., p-Cymene, Gamma-Terpinene, Cumic aldehyde, and 1,4-p-Menthadien-7-al into same cluster which are mainly distributed in Shalimar Kalazeera-1, and Atholi Kishtwar zones. The highest value of gamma-terpinene was recorded in Atholi accession (40.66%). However, among climatic zones Zabarwan Srinagar and Shalimar Kalazeera-1 was found to have highly positive significant correlation (0.99). The cophenetic correlation coefficient (c) was found to be 0.8334 during hierarchical clustering for 12 essential oil compounds showing that our results are highly correlated. Network analysis also showed the overlapping pattern and similar interaction between the 12 compounds as shown by hierarchical clustering analysis. From the results, it could be concluded that existence of variability among the various bioactive compounds of B. persicum which are probably to be incorporated to the potential list of drugs and may serve as good genetic source for various modern breeding programs.

Phytochemical composition, in vitro antioxidant and alpha amylase inhibitory properties of Celosia leptostachya

Plant based phytoconstituents of great importance in the development of drugs and treatment of several health diseases.In this study, the phytochemical constituents of ethanol extract of Celosia leptostachya leaves, invitro antioxidant and alpha amylase inhibitory properties were investigated. Gas chromatography-mass spectrum analysis was used to identify varying percentage composition of phytochemical constituents in the extract. In vitro models were used to evaluate the ability of varying concentrations of the ethanol extracts to exhibit antioxidant activity by free radical scavenging using nitric oxide (NO) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Major constituents are cis-3-Butyl-4-vinyl-cyclo pentene n-Hexadecanoic acid, 9,12-Octadecadienoic acid (Z,Z) , Bicyclo[2.2.1]heptane, 7,7-dimethyl-2-methylene, octadecanoic acid (7.47%), arachidonic acid and 9-octadecenoic acid (E) (5.40%). Many of the constituents are also representative compounds belonging to fatty acid esters and volatile oils. Invitro antioxidant studies using DPPH and NO radical scavenging activity indicated that the extract exhibited > 50% inhibition at concentrations of 500 µg/ml and 600 µg/ml. IC50 values obtained for the extracts indicated strong antioxidant activity. Alpha amylase inhibition showed that increase in concentration of the extract exhibited a corresponding increase in percentage inhibition of the enzyme similar to acarbose used as standard. The kinetic studies under inhibitory conditions showed a decrease in Km and Vmax from slope and noncompetitive. Thus, it can be deduced that ethanol extract of Celosia leptostachya leaves contained essential phytochemical components that can be explored for broad spectrum bioactivity, pharmacological and nutritional applications. The inhibition mechanism is noncompetitive and can be utilized as strategy in control and treatment of hyperglycemia.

Assessment of Phytochemical, FT-IR and GC-MS Fingerprint Profiling of Marine Angiosperms Enhalus acoroides (L.f) Royle and Syringodium isoetifolium (Asch) Dandy, Gulf of Mannar Biosphere Reserve, Tamil Nadu

Objectives: Seagrasses, the marine angiosperm plants, grow in saline environments. Fully submerged in the sea, they are widely distributed along the Gulf of Mannar biosphere reserve regions of Tamil Nadu. The current study was carried out to evaluate the possible bioactive components, present in seagrasses Enhalus acoroides and Syringodium isoetifolium. Methodology : Petroleum ether, benzene, ethyl acetate, methanol, ethanol and aqueous extracts were subjected to qualitative test for the identification of phytoconstituents as per standard procedure. The functional groups of plant powder were identified using FTIR analysis. The ethanol extraction were analyzed via GC-MS techniques. Results: The presence of catechin, flavonoid, phenol, saponin, tannin and glycoside is revealed through the phytochemical screening of the diverse solvent extracts of E. acoroides and S. isoetifolium. The Fourier Transform-Infra Red (FT-IR) spectroscopy analysis confirmed the presence of hydroxyl, phenolics/alcohol, alkane, ester, ether, amine and others. The Gas Chromatography-Mass Spectrum (GC-MS) analysis showed the presence of each ten phytocompounds including n-Hexadecanoic acid, phytol, stigmasterol, hexadecanoic acid and methyl ester. Conclusion: The analyses proved the presence of important bioactive compounds with medicinal properties in the marine angiosperms found in the Gulf of Mannar biosphere reserve regions of Tamil Nadu. The therapeutic effects of seagrasses were the results of the presence of bioactive components in them.

Effect of Tremella fuciformis polysaccharide on the stalling and flavor of tteok during storage

The effect of Tremella fuciformis polysaccharide (TFP) on the retrogradation property and aroma profile changes of tteok during storage was investigated. Results indicated that addition of TFP significantly increased the stability to thermal and mechanical shearing of starch, decreased short-term retrogradation, the hardness and the retrogradation enthalpy (ΔH) of tteok during storage, but had no significant effect on the amylopectin chain length of tteok. The possible mechanism for the retarding staling effect of TFP is related to the interaction between TFP and starch chains that interferes with the alignment of starch chains. Electronic nose and gas chromatography-mass spectrum (GC-MS) analysis results showed that the difference in the concentrations of volatile compounds and fatty acids of tteoks at different storage time gradually increased with the advancement of storage period. The addition of TFP to tteok inhibited the development of unpleasant volatile compounds, probably by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds in tteok, thus slowing down the flavor deterioration of tteok and contributing to flavor maintainace. Overall, this study could help food manufacturers to choose a high-effective and natural polysaccharide to control the retrogradation rate and flavor loss of tteok.

English

The present study was carried out to assess the effect of methanol leaf extract of Uvaria chamae using Gas Chromatography-Mass Spectrum (GC-MS) to determine the phytochemicals present and its effect on the histology of midgut of maize weevil, Sitophilus zeamais. Insects were administered with 10 mg/kg of the plant extract using diffusion method where insects were put in a petri dish containing various concentrations and observed to see the stage they begin to die due to toxicity and observed for 5 min. They were collected into foil processing paper and fixed in Bouins fluid for 24 h, repacked after 24 h and folded in fresh foil immersed in buffered formalin for histopathological studies. Result revealed that a severe degeneration de-arrangement of the respiratory tract epithelial lining, secretory lining cells and gastrointestinal layers with the destruction of the muscular layer when compared with the control. The methanol leaf extracts of U. chamae were preliminary screened for the phytochemicals. The extract shows the presence of cardiac glycosides, saponin, steroids/terpenes, flavonoids, alkaloids and phenols. GC-MS analysis of the extract showed the presence of 2-nitrobenzaldehyde (4.00), malic acid (2.04), L-aspartic acid (2.00), 1, 1, dimethylhydrazine (1.86), Cedrandiol (1.75), 2-amino-4-(2-methylpropenyl)-pyrimidin-5-carboxylic acid (1.56), thiirane (1.54), mercaptoethanol (1.11) and some minor compounds. The findings indicated that methanol extract of U. chamae is rich in phyto-compounds having biological activities on the midguts’ histology of S. zeamais. Therefore, it is recommended as an alternative for the synthetic insecticide used by farmers for the preservation of stored grains. © 2021 Friends Science Publishers

Network Pharmacology Study on Morus alba L. Leaves: Pivotal Functions of Bioactives on RAS Signaling Pathway and Its Associated Target Proteins against Gout.

M. alba L. is a valuable nutraceutical plant rich in potential bioactive compounds with promising anti-gouty arthritis. Here, we have explored bioactives, signaling pathways, and key proteins underlying the anti-gout activity of M. alba L. leaves for the first-time utilizing network pharmacology. Bioactives in M. alba L. leaves were detected through GC-MS (Gas Chromatography-Mass Spectrum) analysis and filtered by Lipinski’s rule. Target proteins connected to the filtered compounds and gout were selected from public databases. The overlapping target proteins between bioactives-interacted target proteins and gout-targeted proteins were identified using a Venn diagram. Bioactives-Proteins interactive networking for gout was analyzed to identify potential ligand-target and visualized the rich factor on the R package via the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway on STRING. Finally, a molecular docking test (MDT) between bioactives and target proteins was analyzed via AutoDock Vina. Gene Set Enrichment Analysis (GSEA) demonstrated that mechanisms of M. alba L. leaves against gout were connected to 17 signaling pathways on 26 compounds. AKT1 (AKT Serine/Threonine Kinase 1), γ-Tocopherol, and RAS signaling pathway were selected as a hub target, a key bioactive, and a hub signaling pathway, respectively. Furthermore, three main compounds (γ-Tocopherol, 4-Dehydroxy-N-(4,5-methylenedioxy-2-nitrobenzylidene) tyramine, and Lanosterol acetate) and three key target proteins—AKT1, PRKCA, and PLA2G2A associated with the RAS signaling pathway were noted for their highest affinity on MDT. The identified three key bioactives in M. alba L. leaves might contribute to recovering gouty condition by inactivating the RAS signaling pathway.

Gas Chromatography-Mass Spectrum andFourier-transform infrared spectroscopy analysis of Fixed Oil from Sudanese Ziziphus spina Christi Fruits Pulp

The study was carried out in reason of investigating the phytochemical constituents that could be present in the Ziziphus spina Christi Sudanese plant, by using two different analytical methods such as the Gas Chromatography-Mass spectrum (GC-MS) and the Fourier-transform infrared spectroscopy (FTIR). The Z. spina Christi Fruit pulp oil was extracted with four solvents methanol, petroleum ether, acetone, and isopropyl alcohol, using Soxhlet apparatus, The Gas Chromatography-Mass Spectrum (GC-MS) was carried out to analyze the methanolic fruit pulp oil extract, the results indicated to the presence of thirty-two phytochemical compounds. Ten of them are majors, namely9-Octadecenoic acid compounds, methyl ester, (E) - (17.07%), 7-Oxabicyclo[4.1.0]heptane,1-methyl-4-(2-methyloxiranyl)- (16.43%), 9-Octadecenoic acid (Z) -, methyl ester (10.6%), Hexadecanoic acid, methyl ester (8.78%), methyl stearate (6.71%), Docosanoic acid, Methyl ester (4.22%), cis-13-Eicosenoic acid, methyl ester (3.43%)%), methyl 18-methylnonadecanoate (2.98%), squalene (2.38%), 9-tricosine, (Z) - (2.4%).While the Fourier-transform infrared spectroscopy (FTIR) analysis was carried out for ( methanol, petroleum ether, acetone, and isopropyl alcohol ) fruit pulp oil extract the result showed the presence of many active functional groups such as alcohols, phenols, alkanes, alkenes, carbonyls, and Carboxylic acids and aromatic compounds in the extracts with different peak types and correspondences. The GC-MS and FTIR analysis showed the availability of bioactive compounds in the Ziziphus spina fruits pulp oil extracts, and these ingredients may be responsible for pharmaceutical value and could lead to the discovery a novel drugs

Gas Chromatography-Mass spectrum and Infra-Red spectral analysis of Fixed Oil from Sudanese Adansonia digitata Seeds

Gas Chromatography-Mass spectrum and Infra-Red spectral analysis of Fixed Oil from Sudanese Adansonia digitata Seeds

Evaluation of Bioactive Compound from Cashew Apple Juice by Gas Chromatography–Mass Spectrum Analysis

Evaluation of Bioactive Compound from Cashew Apple Juice by Gas Chromatography–Mass Spectrum Analysis

Gas Chromatography-Mass Spectrometry (GC-MS) Analysis and Antioxidant Activity of Sea-Cucumber (Holothurian atra and Holothurian edulis) From Selayar Island

The present investigation was carried out to characterize the bioactive compounds present in extract of Holothurian atra and Holothurian edulis using Gas Chromatography-Mass Spectrum (GC-MS) and antioxidan activity. The results of the GC-MS analysis provide different peaks determining the presence of 4 phytochemical compounds with different therapeutic activities. The measurement of antioxidant activity carried out using 1,1difenil-2-pikrihidazil (DPPH) method. The major, 9-Octadecenoic acid (Z)-, methyl ester (47.29), hexadecanoic acid, methyl ester (28.41), octadecanoic acid, methyl ester (4.47), and [1,1′-bibicyclo[2.2.2]Octane]-4-carboxylic acid (92.11) and minor compounds were also present. Antioxidant activity of the ethanolic extract of Holothurian edulis have low antioxidant activity with the value IC50 41.6828 mg/mL and ethanolic extracts of Holothurian atra have strong antioxidant activity with value IC50 33.514 mg/mL. From the results, it could be concluded that Holothurian atra and Holothurian edulis contains various bioactive compounds have various biological activities and antioxidant activity.

In vitro potential activity of some seaweeds as antioxidants and inhibitors of diabetic enzymes

Abstract In this study crude extracts of Turbinaria decurrens, Padina pavonica, Sargassum muticum and Sargassum acinarium (Phaeophyta); Ulva lactuca (Chlorophyta) and Pterocladia capillacea (Rhodophyta) seaweeds were tested to evaluate their antioxidant properties and antidiabetic potential on α-amylase and α-glucosidase starch hydrolyzing enzymes. The results showed that all analyzed seaweeds exhibited antioxidant effects using DPPH (2,2-Diphenyl-1-picrylhydrazyl), reducing power and total antioxidant capacity assays in addition to antidiabetic activity that all depended on the species and the extract solvent. Among the tested extracts, acetone extract of Turbinaria decurrens showed the highest antioxidant activity and inhibitory effects for α-amylase (96.1%) and α-glucosidase (97.4%), respectively which was related with its total phenolic content and antioxidant activity. In vitro, the extract showed no toxicity against fibroblast normal cell lines at lower concentration of 250 µg/ml. Gas Chromatography-Mass Spectrum analysis (GC-MS) of this acetone extract showed the presence of different bioactive compounds mainly cyclotrisiloxane, hexamethyl which could be responsible for its antioxidant and antidiabetic activities. The study results suggest that brown seaweeds especially T. decurrens can be used as antioxidant ingredients and as potent reducing drug for postprandial hyperglycemia.

Physical, chemical, and biological treatment of chemical waste from teaching laboratories at Universidad Nacional, Costa Rica

Herein, we report the physical, chemical, and biological treatment of wastewater generated in the teaching laboratories at Universidad Nacional, Costa Rica. Initial physicochemical treatment included neutralization and coagulation-flocculation, followed by a biological treatment with fungi (Aspergillus sp. and Penicillium dipodomyicola) or bacterias, the latter were isolated from the sludge from the campus’ wastewater treatment plant and the greywater collection tank at the School of Chemistry. The samples’ pH prior to treatment was ≤ 2, while COD ranged between 3000 and 30 000 mg/L. Gas chromatography-mass spectra analysis indicated the presence of 55 organic compounds in the wastewater, some of which reached undetectable concentrations after treatment. The fungi and the bacterial strain removed up to 50% of the substances, while the toxicity decreased with respect to time of exposure to the treatment. Results support the potential use of these microorganisms as bioremediators. Although the organic compounds were partially removed, the treated wastewater exhibited high toxicity for Daphnia magna (water flea). Further experiments with longer treatment times or other strains might be needed for effective removal of pollutants.

Fatty Acid Evaluation and Antimicrobial Activity of Virgin Coconut Oil and Activated Virgin Coconut Oil on Streptococcus mutans

For decades, coconut oil was reported to possess a broad spectrum of antimicrobial activity due to its abundant fatty acid’s contents. Streptococcus mutans (S. mutans) has been strongly implicated as the main etiological factor in dental caries. Regardless of the ongoing medical advances, the therapeutic resources for dental caries remain ineffectual, and this has led to renewed interest in using virgin coconut oil (VCO) as a possible choice for dental caries control. In this study, the ability of VCO and activated virgin coconut oil (AVCO) combatting cariogenic S. mutans ATCC 25175 has been evaluated. Fatty acids contents were compared through Gas Chromatography-Mass Spectrum (GC-MS) analysis, and their antimicrobial activity was determined using disc diffusion and minimum inhibitory concentration (MIC) test. From the GC-MS analysis, AVCO (59%) was found to have a slightly higher medium-chain fatty acids (MCFA) as compared to VCO (54.1%), and the long-chain fatty acids (LCFA) contents in VCO (45.9%) was found to be higher than AVCO (41%). Interestingly, S. mutans ATCC 25175 was found to be susceptible towards AVCO (MIC: 6.24 mg/ml) and resistance towards VCO in vitro. The excellent antimicrobial activity of AVCO as a result from (i) the release of individuals fatty acids after activation of virgin coconut oil by lipase digestion and (ii) the present of MCFA and LCFA that are significant in antimicrobial activity. Further study can be designed to specifically examine the activity of individuals fatty acids present in oils against S.mutans virulence genes/protein using molecular dynamic assessment.

Liquid polycarbosilane as a potential chemical liquid vapour deposition precursor for SiC

Abstract A low-viscous liquid polycarbosilane (LPCS) is being proposed as a silicon carbide (SiC) precursor for chemical liquid vapour deposition (CLVD) process. The LPCS was characterized by Gel permeation chromatography (GPC), Fourier transformation infrared (FT-IR) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, GC-MS and Thermogravimetric analysis (TGA). Spectroscopic investigations together with Gas chromatography Mass spectrum (GC-MS) indicated that the synthesized LPCS is a mixture of cyclic/linear silanes and carbosilanes. TGA showed the complete evaporation of the LPCS below 250 °C, a suitable property for application as a CLVD precursor. Ceramic conversion of LPCS at different temperatures (900 °C, 1100 °C and 1300 °C) under argon, indicated the formation of nano-sized crystallites of β-SiC at 1300 °C.