Solvent Extraction Procedure Research Articles

A Novel Selective Accelerated Solvent Extraction for Effective Separation and Rapid Simultaneous Determination of Six Anthraquinones in Tartary Buckwheat and Its Products by UPLC–DAD

A novel analytical method is developed for effective separation and rapid simultaneous determination of anthraquinones in Tartary buckwheat by ultra-performance liquid chromatography coupled to a diode array detector (UPLC−DAD). A selective accelerated solvent extraction (SASE) procedure combines an accelerated solvent extraction (ASE) and cleanup in situ. SASE conditions were investigated and optimized in the details. Methanol/acetone (50:50, v/v) was selected as solvent for the extraction, and silica gel was selected as sorbents for clean-up. The SASE procedure simplified further the entire sample preparation chain and achieved satisfactory results in the analyses of anthraquinones compared with traditional extraction methods. The effective separation of six anthraquinones from an extract of Tartary buckwheat on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column using gradient elution was achieved within 7 min. Good linearity was achieved, with a correlation coefficient (r 2) of ≥0.9998. The limit of detection (LOD) and the limit of quantification (LOQ) were in the range of 0.033–0.067 μg/mL and 0.1–0.2 μg/mL, respectively. Under the optimized conditions, good recovery (98.3–109 %) of the anthraquinones was achieved. The validated method is successfully applied to the quality assurance of the anthraquinones in Tartary buckwheat and its products.

Standardization of solvent extraction procedure for determination of uranium in seawater

Solvent extraction procedure using ammonium pyrolidine dithiocarbamate complexing agent in methyl isobutyl ketone organic phase and acid exchange back-extraction is described for the simultaneous quantitative pre-concentration of uranium in seawater followed by its determination by differential pulse adsorptive stripping voltammetry. Solvent extraction time is optimized for extraction of uranium from seawater. Solvent extraction efficiency for uranium in seawater at different pH was carried out. The method gives a recovery of 98 ± 2 % for 400 mL sample at pH 3.0 ± 0.02, facilitating the rapid and interference free analysis of seawater samples.

A simple QuEChERS-like extraction approach for molecular chemical characterization of organic aerosols: application to nitrated and oxygenated PAH derivatives (NPAH and OPAH) quantified by GC–NICIMS

An extraction procedure based on the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) approach has been developed and used for analysis of particle-bound nitrated and oxygenated PAH derivatives (NPAH and OPAH, respectively). Several analytical conditions, for example GC injection temperature and MS detection settings, were optimized. This analytical procedure enabled simultaneous GC-NICIMS quantification of 32 NPAH and 32 OPAH (or other oxygenated compounds), including typical components of secondary organic aerosol (SOA) formed by photooxidation of PAH (e.g. 2-formyl-trans-cinnamaldehyde and 6H-dibenzo[b,d]pyran-6-one). The QuEChERS-like approach was optimized, including the nature of the extraction solvent, the sorbent used for clean-up, and extraction time. The final extraction procedure was based on brief mechanical agitation (vortex mixing for 1.5min), with 7mL acetonitrile as solvent. Because dispersive solid-phase extraction (d-SPE) did not provide satisfactory results, SPE using SiO2 was selected for sample purification. Identical results were obtained when the QuEChERS-like and traditional pressurised solvent extraction (PLE) procedures were compared for analysis of fortified ambient air particle samples. The procedure was validated by analysis of two aerosol standard reference materials (NIST SRM 1649b (urban dust) and SRM 2787 (fine particulate matter, <10μm)). For numerous NPAH and OPAH, this is the first report of their quantification in both SRMs. Compared with other extraction methods, including PLE, the QuEChERS-like procedure resulted in increased productivity and reduced extraction cost. This paper shows that QuEChERS-like extraction procedures can be suitably adapted for molecular chemical characterization of aerosol samples and could be extended to other categories of compound.

Total Phospholipids in Edible Oils by In-Vial Solvent Extraction Coupled with FTIR Analysis

A simple procedure for the determination of total phospholipids (TPL) in edible oils was developed by combining a single-step, in situ methanol/acetonitrile (MeOH/ACN) extraction of the oil sample followed by Fourier transform infrared (FTIR) spectroscopic analysis of the extract. Spectral analysis of extracts in a 25 μm CaF2 cell obtained using 1:1 MeOH/ACN added to oil in a 2:1 ratio indicated that measurements made using only the asymmetric phosphate diester PO2- stretching band at 1243 cm-1 in second-derivative spectra were sufficient for the accurate measurement of TPL with minimal coextracted triglyceride interferences being encountered. FTIR calibration spectra were devised using only phosphatidylcholine (PC) as a representative phospholipid standard, covering a range of 0-50000 μg/g TPL and spiked into 1:1 MeOH/ACN, capable of tracking the added PC with an SD of <200 μg/g. The FTIR method was initially validated using model PC-spiked degummed canola oil and subsequently with commercial crude and refined soy and rapeseed oils as well as a lecithin tablet with the FTIR TPL predictions compared to those of the AOCS Ca 12-55 molybdenate method. The FTIR method tracked the AOCS results well, being somewhat more reproducible than the reference method (±3.2 vs ±4.9%), which limited its accuracy relative to the AOCS reference procedure (±2.2%). The simple in-vial solvent extraction procedure, followed by FTIR analysis of the extract, is a simple, efficient, and rapid procedure that is also amenable to automation using an autosampler-equipped FTIR if multiple samples are to be analyzed.

Analysis of low-level 129I in brine using accelerator mass spectrometry

An improved solvent extraction procedure for iodine separation from brine samples has been applied at Xi’an Accelerator Mass Spectrometry (AMS) center. Oil in the brine sample has to be removed to avoid appearance of the third phase during solvent extraction and to improve the chemical yield of iodine. The small amount of oil remained in the water phase was first removed by phase separation through settling down sufficiently based on their immiscibility, and then by filtration through a cellulose filter, on which oil was absorbed and removed. After oil removed, extraction recovery of iodine could achieve more than 90 %. The sodium bisulfite as an effective reductant should be added before acidification to avoid loss of iodine by formation of I2 in sample via reaction of iodate and iodide at pH 1–2, and then pH was adjusted to 1–2 to reduce the iodate to iodide followed by oxidation of iodide to I2 and solvent extraction to separate all inorganic iodine. As a pre-nuclear era sample, 129I/127I ratio in brine is normally more than two orders of magnitude lower than that in present surface environmental samples, so prevention of cross-contamination and memory effect in apparatus during processing procedure are very critical for obtaining reliable results, and monitoring the procedure blank is very important for analytical quality of 129I. The 129I/127I isotopic ratio in the brine samples and procedure blank of iodine reagents were measured to be (1.9–2.7) × 10−13 and 2.08 × 10−13, respectively, 3–4 orders of magnitudes lower than that in environmental samples in Xi’an, and the result of procedure blank is in the same level as the previous experiments in past 3 years, indicating contamination is not observed in our method.

DETERMINATION OF PAHs IN LUNG TISSUE SAMPLES USING SPECIFIC CHROMATOGRAPHIC TECHNIQUES: METHOD DEVELOPMENT AND VALIDATION

Quantification of polycyclic aromatic hydrocarbons (PAHs) in lung tissue samples for the estimation of clinical impact was carried out. Methods and Materials: A high pressure liquid chromatography system (HPLC) with ultraviolet-visible diode array detector (DAD) and fluorescence (FLD) detection was used. An automated solvent extraction (ASE) procedure with sample clean-up was employed for the extraction of PAHs from the lung tissue samples. The chromatographic method allowed identification of a total number of 16 PAHs: naphtalene, acenaphthene, fluorene, phenanthrene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)perylene, and indeno(1,2,3-cd)pyrene using fluorescence detection, whereas acenaphtylene was identified using a diode array detector (DAD). Results: The linearity domain for the method was between 5 pg/µL and 400 pg/µL for each compound. The quantification limits were between 0.5 pg/µL and 20 pg/µL. Automated solvent extraction was used for obtaining recoveries between 82–120%.

Physiological mechanism of hypertolerance of cadmium in Kentucky bluegrass and tall fescue: Chemical forms and tissue distribution

Kentucky bluegrass (Poa pratensis) and tall fescue (Festuca arundinacea) are hypertolerant grasses to soil cadmium contamination. Little information is available on their tolerance mechanism. A sand culture and a hydroponic culture experiment were designed to investigate the Cd chemical form changes and its translocation in different tissues. The results showed that Kentucky bluegrass and tall fescue can tolerate 50–200mgkg−1 of soil Cd stresses and accumulate as high as 4275 and 2559mgCdkg−1 DW, respectively, in their shoots without the loss of shoot biomass. Their Cd hypertolerance was correlated with an increase of the undissolved Cd phosphates in the leaves in both grass species, as determined by sequential solvent extraction procedures. The superior Cd tolerance of tall fescue to Kentucky bluegrass was associated with less Cd translocation into the stele of roots and less Cd transported to leaves. The pectate- and protein-integrated Cd forms may be involved in the symplastic translocation of Cd from cortex into stele, and this may lead the higher Cd concentrations in the stele of roots and then above ground leaves via long-distance transport in Kentucky bluegrass.

Simultaneous determination of 23 flavor additives in tobacco products using gas chromatography–triple quadrupole mass spectrometry

A method based on gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC–QqQ MS/MS) was developed for the determination of 23 widely used flavor additives in tobacco products in this paper. The MS/MS fragmentation pathway of the cinnamic esters additives was illustrated. The new analytical method was defined based on two main axes, ultrasonic solvent extraction procedure with dichloromethane and analyte detection performed by GC–QqQ MS/MS in electron impact mode. The excellent selectivity and sensitivity achieved in multiple reactions monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the tobacco flavor additives. The linear range of the 23 flavor additives is 0.2–500.0μg/L with good correlation coefficients (r2>0.9963). The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range 0.1–2.0μg/L and 0.4–6.0μg/kg, respectively. The average recoveries at three spiked levels (LOQ, 2LOQ, 4LOQ) were all in the range 62.1–93.8% with RSDs (n=6) lower than 7.8%. The method of GC–QqQ MS/MS developed in this study was initially applied to the research of flavor additives in 12 retail cigarette samples and proved to be accurate, sensitive, convenient and practical.

Molecular‐Level Insights into the Oxidative Degradation of Grafted Amines

The oxidative degradation of CO2 adsorbents consisting of amine-grafted pore-expanded mesoporous MCM-41 silica was investigated. The adsorbents were treated under flowing air at various temperatures, and the degree of deactivation was evaluated through the measurement of their CO2 adsorption capacity prior and subsequent to exposure to air. To decipher the chemical structure of surface species upon air-deactivation of grafted amines, a solvent extraction procedure was developed using a deuterated basic solution. The obtained solutions were analyzed by a variety of 1D and 2D NMR spectroscopy techniques, such as (29)Si, (13)C, (1)H, [(1)H,(15)N] HMBC, [(1)H,(13)C] HMQC, COSY and DOSY. The surface species generated by oxidative degradation of amine-grafted silica were found to contain functional groups such as imine, amide and carboxylic groups. Several structural units were conclusively demonstrated.

Fucoxanthin from Undaria pinnatifida: photostability and coextractive effects.

Fucoxanthin is one of the most abundant carotenoids and possesses a number of beneficial medicinal qualities which include its anti-oxidant, anti-obesity and anti-cancer properties. In this study, the photostability of fucoxanthin in extracts with different chemical profiles was studied. The extracts were obtained from Undaria pinnatifida, a seaweed rich in this carotenoid, using conventional liquid solvent extraction procedures and the QuEChERS method. All the extracts contained all-trans-fucoxanthin as the major compound. Conventional procedures produced a fucoxanthin purity of lower than 50%, whereas after liquid-liquid partition, PSA cleanup, and PSA and GCB cleanup (QuEChERS method) fucoxanthin purity increased to 70%, 86%, and 94%, respectively. Although in the acetone extract the initial content of fucoxanthin was the highest, results demonstrate that coextractives play an important role in enhancing the rate of photodegradation. After light exposure, the conventional extracts lost around 90% of the initial fucoxanthin content. On the other hand, the extracts obtained by the QuEChERS method showed significantly higher light stability than the conventional extracts. These results suggest that the QuEChERS method could be used and further improved to obtain more purified and stable extracts for fucoxanthin from U. pinnatifida.

Rapid method for rhaponticin and deoxyrhaponticin separation and determination by TLC inRheum rhaponticumL. andRheum undulatumL.

Summary The study describes the solvent extraction procedure and improved version of TLC method for the determination of rhaponticin and deoxyrhaponticin in rhizomes and petioles of two species of Rheum L. genus. Extracts from underground parts and petioles of plant were separated on thin layers of silica using a mixture of dichloromethane-95% ethanol-methanol (8:1:1). The bands of rhaponticin and deoxyrhaponticin were satisfactorily separated from the remaining extract components permitting their densitometric quantitative and qualitative determination. The concentration of these compounds in Rheum undulatum was higher than in Rheum rhaponticum. The amount of rhaponticin and deoxyrhaponticin ranged between 0.3 and 31.5 mg/g.

A really quick easy cheap effective rugged and safe (QuEChERS) extraction procedure for the analysis of particle-bound PAHs in ambient air and emission samples

A quick easy cheap effective rugged and safe (QuEChERS) like extraction procedure is presented for the measurement of polycyclic aromatic hydrocarbons (PAHs) associated to particulate matter from ambient air or combustion process. The procedure is based on a short mechanical agitation (vortex during 90s) using a small volume of acetonitrile (7ml) as extraction solvent. Equivalent extraction efficiencies were obtained when comparing the QuEChERS and the traditional pressurized solvent extraction (ASE) procedures for ambient air and emission (wood combustion) filter samples. The developed QuEChERS extraction protocol was validated with the analysis of a standard reference material (NIST SRM 1649a, urban dust). By comparison to other extraction methods including ASE, the simplicity of the QuEChERS protocol allows to minimize experimental errors, to decrease about a factor 5 the cost per extraction and to increase the productivity per working day by a 10-fold factor. This paper constitutes the first report on the applicability of a QuEChERS-like approach for the quantification of PAHs or other organic compounds in atmospheric particulate matter.

Heptane as a less toxic option than hexane for the separation of vitamin E from food products using normal phase HPLC

The term ‘vitamin E’ refers to a group of eight vitamers (alpha-, beta-, gamma-, delta-tocopherols and tocotrienols). Its primary role is thought to be as an antioxidant commonly added to a variety of foods, e.g. bakery products. High-Performance Liquid Chromatography (HPLC) procedures are used for the separation and analysis of these tocopherols and tocotrienols in foods. The use of a normal phase column is the preferred approach in such methods, with hexane almost universally utilised as the mobile phase. However there is increasing concern regarding the toxicity of hexane. Here we evaluate the use of heptane as a replacement for hexane in HPLC based vitamin E analysis. The two solvents were compared using samples of bread fortified with palm oil (as a source of vitamin E). Accelerated solvent extraction procedure followed by HPLC showed the effective separation of the E vitamers in a variety of bread samples using both solvents. It is concluded that heptane provides effective separation and quantification of the E vitamers found in cereals and cereal products while also reducing operator risk.

Comparative Analysis of Sample Preparation Methods To Handle the Complexity of the Blood Fluid Metabolome: When Less Is More

Blood sample preparation before LC-MS metabolomic fingerprinting is one of the most challenging and error-prone parts of the analytical procedure. Besides proteins, phospholipids contained in blood fluids are known to cause matrix effects and ion suppression phenomena, thus masking biological variation. Nevertheless, the commonly used sample preparation techniques do not consider their removal prior to analysis. Pooled plasma and serum samples were used as biological material, partly as raw samples and partly spiked with distinct concentrations of a metabolite mix (1-5 μg/mL). Prior to LC-ESI-qToF-MS-driven metabolomic analysis, samples were subjected to different preparation methods consisting of three extractions with organic solvents (acetonitrile, methanol, and methanol/ethanol), a membrane-based solvent-free technique, and a hybrid method combining solvent extraction and SPE-mediated removal of phospholipids. The comparative analysis among sample preparation procedures was based on the capacity to detect endogenous compounds in raw samples, differentiate raw versus spiked samples, and reveal real-life metabolomic changes, following a dietary intervention. Method speed, minimum sample handling, compatibility to automation, and applicability to large-scale metabolomic studies were also considered. The combination of solvent deproteinization and the selective removal of phospholipids was revealed to be the most suitable method, in terms of improvement of nonlipid metabolite coverage, extraction reproducibility, quickness, and compatibility with automation, the minimization of matrix effects being among the most probable causes for the good extraction performance associated with the removal of phospholipid species. The main advantage of conventional solvent extraction procedures was the metabolite information coverage for lipid low-molecular-weight species, and extraction with acetonitrile was generally the second choice for sample preparation. Ultrafiltration was the least effective method for plasma and serum preparation; thus, its use without a previous solvent extraction step of the samples should be discarded. According to the presented data, there is no apparent reason to believe that sacrificing information on lipid compounds is too high of a price to pay in order to gain more information on nonlipid LMW metabolites.

GC/MS analysis of water-soluble organics in atmospheric aerosol: optimization of a solvent extraction procedure for simultaneous analysis of carboxylic acids and sugars

The main goal of the present study was to develop a procedure for the simultaneous GC/MS analysis of a wide range of water-soluble organic compounds (WSOCs, mainly dicarboxylic acids and sugars) in atmospheric aerosol as chemical markers of atmospheric processes. The response surface methodology, including central composite design, was applied to systematically investigate and optimize the operating conditions of a solvent extraction method as the most widely used procedure for determining WSOCs in particulate matter (PM) samples. A solvent mixture of methanol/dichloromethane (90:10) and a volume of 10 ml were the optimum conditions that permit the simultaneous analysis of 30 target WSOCs, including dicarboxylic acids and sugars. Recoveries and limits of detection were determined for a standard mixture containing target analytes, and they varied from 79 to 103 % and 0.3 to 1 ng m(-3), respectively. The optimized procedure was used for the analysis of field PM filters and demonstrated its feasibility in detecting several important environmental WSOCs.

Interfacial sorption/desorption studies of Pu(IV) on Silica and alumina surfaces

AbstractCombination of sorption, desorption and kinetic experiments for Pu(IV) in silica and alumina suspensions over the pH range (2–9) have been employed to study the factors controlling Pu mobility from the near field of the repositories. These studies have been carried out using shorter lived isotope of Pu (238Pu) thereby achieving Pu concentration (∼10-9M) near the solubility limit. Kinetic experiments were carried out to investigate the mechanism of the sorption process. In order to conclude about the surface speciation, desorption and leaching studies have been carried out on short as well as long time equilibrated sorption samples. Oxidation state transformation in the kinetic experiment was determined using parallelly carried out solvent extraction procedures. Silica was found governing the sorption at pH values≲ 5.5while both the surfaces quantitatively sorb the metal ion at higher pH values. The leaching and desorption experiments, in light of kinetic experiments, concluded the formation of small polynuclear Pu(IV) oxide/hydroxide species on both the surfaces. These experiments did not show any evidence for PuO2(am.) as the surface speciation. Oxidation state determination in silica supernatants revealed V as the oxidation state of Pu, while alumina suspensions favour higher oxidations state,i.e., (VI) over (V) in the supernantant. Disproportionation of Pu(V) in the interfacial region, caused by the higher sorption affinity of alumina, produces Pu(VI) in the alumina supernatant. These findings provide new insight for defining the source term of Pu migration in geosphere.

A new strategy for pressed powder eye shadow analysis: Allergenic metal ion content and particle size distribution

Nine cheap eye shadow products were analyzed through graphite furnace atomic absorption spectrometry (GF-AAS) to quantify their Cr, Co and Ni contents, all known to be skin sensitizers. In many cases, the concentrations were higher than 1 or 5ppm (μg/g), i.e. the limits recommended in the scientific literature to minimize the risk of reaction in particularly sensitive subjects. In most cases, the concentration of Cr was higher than that of Ni and Co, up to a limit case of 150mg/g. In this particular sample, the potential amount of Cr that could be released in ionic form was determined in sweat simulating solutions by GF-AAS and confirmed through a specific spectrofluorimetric method; the results indicated the presence of approximately 80–90ppb (ng/g) of Cr3+.The water dispersible particles were isolated from the eye shadow powders through a simple solvent extraction procedure. The aqueous suspensions were then sorted through sedimentation field flow fractionation (SdFFF) and the particles sizes were calculated from experimental fractograms using theory. For the most part, the computed sizes were in the micron range, as confirmed by some SEM photographs taken on fractions collected during the separations. The SdFFF coupled off-line with the GFAAS enabled elemental characterization of pigment particles as a function of size. This finding reduces the concern that the ingredients of such makeup formulations may contain nanoparticles.

Determination of siloxanes in silicone products and potential migration to milk, formula and liquid simulants

A pressurised solvent extraction procedure coupled with a gas chromatography–mass spectrometry–selective ion monitoring (GC–MS–SIM) method was developed to determine three cyclic siloxanes, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6) and three linear siloxanes, octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5), in silicone products. Additionally, two different extraction methods were developed to measure these siloxanes migrating into milk, infant formula and liquid simulants (50 and 95% ethanol in water). The limits of quantification (LOQs) of the six siloxanes ranged from 6 ng/g (L3) to 15 ng/g (D6). Silicone nipples and silicone bakewares were extracted using pressurised solvent extraction (PSE) and analysed using the GC–MS–SIM method. No linear siloxanes were detected in the silicone nipple samples analysed. The three cyclic siloxanes (D4, D5 and D6) were detected in all silicone nipple samples with concentrations ranging from 0.5 to 269 µg/g. In the bakeware samples, except for L3, the other five siloxanes were detected with concentrations ranging from 0.2 µg/g (L4) to 7030 µg/g (D6). To investigate the potential migration of the six siloxanes from silicone nipples to milk and infant formula, a liquid extraction and dispersive clean-up procedure was developed for the two matrices. The procedure used a mix of hexane and ethyl acetate (1 : 1, v/v) as extraction solvent and C18 powder as the dispersive clean-up sorbent. For the liquid simulants, extraction of the siloxanes was achieved using hexane without any salting out or clean-up procedures. The recoveries of the six siloxanes from the milk, infant formula and simulants fortified at 50, 100, 200, 500 and 1000 µg/l ranged from 70 to 120% with a relative standard derivation (RSD) of less than 15% (n = 4). Migration tests were performed by exposing milk, infant formula and the liquid simulants to silicone baking sheets with known concentrations of the six siloxanes at 40°C. No siloxanes were detected in milk or infant formula after 6 h of direct contact with the silicone baking sheet plaques, indicating insignificant migration of the siloxanes to milk or infant formula. Migration tests in the two simulants lasted up to 72 h and the three cyclic siloxanes were detected in 50% ethanol after an 8-h exposure and after 2 h in 95% ethanol. The highest detected concentrations of D4, D5 and D6 were 42, 36 and 155 ng/ml, respectively, indicating very limited migration of D4, D5 or D6 into the two simulants.

LC–MS/MS method for the quantitation of metabolites of eight commonly-used synthetic cannabinoids in human urine – An Australian perspective

An LC–MS/MS method for the quantitation of urinary metabolites of eight JWH-type synthetic cannabinoids (SCs) has been developed and validated. Urine samples are subjected to deconjugation using β-glucuronidase, followed by a solvent extraction procedure. Compounds are separated on a reverse-phase HPLC column within a 14min cycle. Low assay limits are required in order to demonstrate prior exposure to SCs. Matrix effects were studied and proved to be significant for selected analytes, and were challenging to circumvent as isotope-labeled internal standards are not available. An elimination profile from a naïve user following a single smoke of “Kronic” was constructed, showing urinary excretion over 2–3 days with peak concentrations of different metabolites 3–16.5h after smoking. This method has been developed to process several hundred samples within a high-throughput drugs of abuse laboratory, with growing evidence that the use of synthetic cannabinoid blends is common within the Australian workforce.

Inhibitory effects of bioactive leads isolated from Pseudomonas aeruginosa PS3 and Pseudomonas fluorescens PS7 on MAP kinases and down regulation of pro inflammatory cytokines (TNF-α, IL-1β) and mediators (NO, iNOS and COX)

Pure lead molecules, showing anti-inflammatory effect were isolated from the marine Pseudomonas aeruginosa PS3 (GenBank Accession No. EF488968) and Pseudomonas fluorescens PS7 (GenBank Accession No. EF488969) using solvent extraction procedures, subsequent column fractionation, followed by bio activity based screening. The structures of the lead molecules (3S, 8aS)-3-isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione (Compound 1) and (8aS)-3-(4-hydroxybenyl) hexahydropyrrolo[1,2-a]pyrazine-1,4-dione (Compound 2) obtained from P. aeruginosa PS3 and P. fluorescens PS7 respectively were established employing spectral analysis. Compounds 1 and 2 at their IC50 values of 84 and 53μM concentrations respectively down regulated expression of tumor necrosis factor-α (TNF-α) and interleukin 1-β (IL-1β) in peripheral blood mononuclear cells (PBMCs) and inducible nitric oxide synthase (iNOS) gene in RAW 264.7 cells. Immunoblot analysis revealed the inhibitory effect of pure compounds on phosphorylation of all the three mitogen activated protein kinases (MAPK) such as ERK, JNK and p38 MAPK. The results of the present investigation revealed that the pure compounds are anti-inflammatory in nature.