Immunoassays could provide valuable insights into disease biomarkers and gut health by measuring fecal proteins. However, reliably isolating intact proteins from feces is challenging due to its heterogeneous and variable composition. This paper aims to review and compare different methods for extracting proteins from fecal samples to make them suitable for immunoassay analysis. Mechanical homogenization helps release proteins by disrupting solids, while protease inhibitors preserve protein integrity. Detergents like SDS solubilize proteins by disrupting hydrophobic interactions. Organic solvents such as acetone precipitate proteins and remove contaminants. Thermal treatment denatures proteases. Immunocapture uses antibodies to purify target proteins away from interference selectively. Commercial kits contain optimized buffers but may be cost-prohibitive. Combining mechanical, chemical, and immunological techniques synergistically integrates their advantages, improving the recovery of native proteins with reduced matrix effects. While all methods have merits, tailored protocols integrating multiple mechanisms appear most promising for extracting immunoassay-suitable fecal proteins. Further optimization and standardization of such combination approaches matched to proteins and assays of interest helps expand noninvasive fecal proteome analysis.
Malaysian seaweed, particularly Sargassum polycystum, has potential for alginate production, yet an extraction protocol for this seaweed remains lacking. This study aimed to optimize the extraction process to maximize alginate yield while characterizing the physicochemical properties of the extracted alginate and its potential applications. An alkali-based extraction method was employed, with key parameters, including alkali concentration, extraction temperature, and time, carefully optimized to yield 30.17 ± 0.76 % (g alginate/100 g dry seaweed biomass) of alginate. Sodium alginate extracted from Sargassum polycystum has a viscosity-average molecular weight of 4.73 ± 0.001 × 104 g/mol and an M/G ratio of 2.87. The physicochemical properties and biochemical composition of the extracted alginate revealed its capacity to be utilized as a natural antioxidant. An alginate-based nanohybrid for polyphenol delivery was developed to explore the potential applications of extracted alginate. This nanohybrid showed favorable properties (hydrodynamic particle size: 415 nm, PDI: 0.3, zeta potential: -44.7 mV), high encapsulation (80.13 %), and loading efficiency (19.21 ± 1.69 %). Alginate coating on the nanohybrid protected polyphenol from premature release, significantly enhancing its antioxidant activity. These findings suggest that alginate extracted from Malaysian Sargassum polycystum could be a valuable natural material for developing controlled-release delivery systems.
A new chromanone acid, namely caloteysmannic acid (1), along with three known compounds, calolongic acid (2), isocalolongic acid (3) and stigmasterol (4) were isolated from the stem bark of Calophyllum teysmannii. All these compounds were evaluated for their cytotoxic and antioxidant activities in the MTT and DPPH assays, respectively. The structure of compound 1 was determined by means of spectroscopic methods including 1D and 2D NMR experiments as well as HR-EIMS spectrometry. The stereochemical assignment of compound 1 was done based on the NMR results and X-ray crystallographic analysis. The preliminary assay results revealed that all the test compounds displayed potent inhibitory activity against HeLa cancer cell line, in particular with compound 1 which exhibited the highest cytotoxic activity comparable to the positive control used, cisplatin. However, no significant antioxidant activity was observed for all the test compounds in the DPPH radical scavenging capacity assay.
Enterobacter cloacae is a versatile bacterial species inhabiting a wide variety of niches and is capable of metabolising a wide variety of substances as energy resources. The fermentation culture of this bacterial species has successfully yielded one new compound, Rimboxa (1) and three known compounds, i.e. indole-3-carboxaldehyde (2), indole-3-acetic acid (3) and 3,4-di-t-butylaniline (4). Rimboxa (1) is shown to possess the 1,2-oxathiolane core structure. 3,4-Di-t-butylaniline (4) is isolated for the first time from a natural resource. These compounds were isolated and characterised using extensive chromatographic and spectroscopic methods, and were subjected to cytotoxicity evaluations.
Microbial lipases are popular biocatalysts due to their ability to catalyse diverse reactions such as hydrolysis, esterification, and acidolysis. Lipases function efficiently on various substrates in aqueous and non-aqueous media. Lipases are chemo-, regio-, and enantio-specific, and are useful in various industries, including those manufacturing food, detergents, and pharmaceuticals. A large number of lipases from fungal and bacterial sources have been isolated and purified to homogeneity. This success is attributed to the development of both conventional and novel purification techniques. This review highlights the use of these techniques in lipase purification, including conventional techniques such as: (i) ammonium sulphate fractionation; (ii) ion-exchange; (iii) gel filtration and affinity chromatography; as well as novel techniques such as (iv) reverse micellar system; (v) membrane processes; (vi) immunopurification; (vi) aqueous two-phase system; and (vii) aqueous two-phase floatation. A summary of the purification schemes for various bacterial and fungal lipases are also provided.
The aim of the present study was to characterize the phenolic acids, flavonoids, and antioxidant properties of monofloral honey collected from five different districts in Bangladesh. A new high performance liquid chromatography (HPLC) equipped with a UV detector method was developed for the identification of the phenolic acids and flavonoids. A total of five different phenolic acids were identified, with the most abundant being caffeic acid, benzoic acid, gallic acid, followed by chlorogenic acid and trans-cinnamic acid. The flavonoids, kaempferol, and catechin were most abundant, followed by myricetin and naringenin. The mean moisture content, total sugar content, and color characteristics of the honey samples were 18.36 ± 0.95%, 67.40 ± 5.63 g/100 g, and 129.27 ± 34.66 mm Pfund, respectively. The mean total phenolic acids, total flavonoid content, and proline content were 199.20 ± 135.23, 46.73 ± 34.16, and 556.40 ± 376.86 mg/kg, respectively, while the mean FRAP values and DPPH radical scavenging activity were 327.30 ± 231.87 μM Fe (II)/100 g and 36.95 ± 20.53%, respectively. Among the different types of honey, kalijira exhibited the highest phenolics and antioxidant properties. Overall, our study confirms that all the investigated honey samples are good sources of phenolic acids and flavonoids with good antioxidant properties.
A triflavanone, Garcineflavanone A (1) and a biflavonol, Garcineflavonol A (2) have been isolated from the stem bark of Garcinia atroviridis (Clusiaceae), collected in Peninsular Malaysia. Their structures were established using one and two-dimensional NMR, UV, IR and mass spectrometry and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Molecular docking studies of the isolated compounds were performed using docking procedure of AutoDock to disclose the binding interaction and orientation of these molecules into the active site gorge.
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.
A rapid reversed-phase high performance liquid chromatographic method using a monolithic column for the determination of eight catechin monomers and caffeine was developed. Using a mobile phase of water:acetonitrile:methanol (83:6:11) at a flow rate of 1.4 mL min(-1), the catechins and caffeine were isocratically separated in about 7 min. The limits of detection and quantification were in the range of 0.11-0.29 and 0.33-0.87 mg L(-1), respectively. Satisfactory recoveries were obtained (94.2-105.2 ± 1.8%) for all samples when spiked at three concentrations (5, 40 and 70 mg L(-1)). In combination with microwave-assisted extraction (MAE), the method was applied to the determination of the catechins and caffeine in eleven tea samples (6 green, 3 black and 2 oolong teas). Relatively high levels of caffeine were found in black tea, but higher levels of the catechins, especially epigallocatechin gallate (EGCG) were found in green teas.
A greener method based on cloud point extraction was developed for removing phenol species including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 4-nitrophenol (4-NP) in water samples by using the UV-Vis spectrophotometric method. The non-ionic surfactant DC193C was chosen as an extraction solvent due to its low water content in a surfactant rich phase and it is well-known as an environmentally-friendly solvent. The parameters affecting the extraction efficiency such as pH, temperature and incubation time, concentration of surfactant and salt, amount of surfactant and water content were evaluated and optimized. The proposed method was successfully applied for removing phenol species in real water samples.
The main objective of the current work was to evaluate the suitability of ultrasound-assisted extraction (UAE) for the recovery of oil from papaya seed as compared to conventional extraction techniques (i.e., Soxhlet extraction (SXE) and solvent extraction (SE)). In the present study, the recovery yield, fatty acid composition and triacylglycerol profile of papaya seed oil obtained from different extraction methods and conditions were compared. Results indicated that both solvent extraction (SE, 12 h/25 °C) and ultrasound-assisted extraction (UAE) methods recovered relatively high yields (79.1% and 76.1% of total oil content, respectively). Analysis of fatty acid composition revealed that the predominant fatty acids in papaya seed oil were oleic (18:1, 70.5%-74.7%), palmitic (16:0, 14.9%-17.9%), stearic (18:0, 4.50%-5.25%), and linoleic acid (18:2, 3.63%-4.6%). Moreover, the most abundant triacylglycerols of papaya seed oil were triolein (OOO), palmitoyl diolein (POO) and stearoyl oleoyl linolein (SOL). In this study, ultrasound-assisted extraction (UAE) significantly (p < 0.05) influenced the triacylglycerol profile of papaya seed oil, but no significant differences were observed in the fatty acid composition of papaya seed oil extracted by different extraction methods (SXE, SE and UAE) and conditions.
Dendrobium sonia-28 is an important ornamental orchid in the Malaysian flower industry. However, the genus faces both low germination rates and the risk of producing heterozygous progenies. Cryopreservation is currently the favoured long-term storage method for orchids with propagation problems. Vitrification, a frequently used cryopreservation technique, involves the application of pretreatments and cryoprotectants to protect and recover explants during and after storage in liquid nitrogen. However, cryopreservation may cause osmotic injuries and toxicity to cryopreserved explants from the use of highly concentrated additives, and cellular injuries from thawing, devitrification and ice formation. Reactive oxygen species (ROS), occurring during dehydration and cryopreservation, may also cause membrane damage. Plants possess efficient antioxidant systems such as the superoxide dismutase (SOD) and catalase (CAT) enzymes to scavenge ROS during low temperature stress. In this study, protocorm-like bodies (PLBs) of Dendrobium sonia-28 were assayed for the total protein content, and both SOD and CAT activities, at each stage of a vitrification exercise to observe for deleterious stages in the protocol. The results indicated that cryopreserved PLBs of Dendrobium sonia-28 underwent excessive post-thawing oxidative stress due to decreased levels of the CAT enzyme at the post-thawing recovery stage, which contributed to the poor survival rates of the cryopreserved PLBs.
A white-rot fungus of Polyporus sp. S133 was isolated from an oil-polluted soil. The metabolism of pyrene by this fungus was investigated in liquid medium with 5 mg of the compound. Depletion of pyrene was evident during the 30-day growth period and was 21% and 90%, respectively, in cometabolism and metabolism of pyrene alone. Pyrene was absorbed to fungal cells or biodegraded to form simpler structural compounds. Seventy-one percent of eliminated pyrene was transformed by Polyporus sp. S133 into other compounds, whereas only 18% was absorbed in the fungal cell. The effects of pH and temperature on biomass production of Polyporus sp. S133 for pyrene were examined; the properties of laccase and 1,2-dioxygenase produced by Polyporus sp. S133 during pyrene degradation were investigated. The optimal values of pH were 3, 5, and 4 for laccase, 1,2-dioxygenase, and biomass production, respectively, whereas the optimal values of temperature were 25 °C for laccase and 50 °C for 1,2-dioxygenase and biomass production. Under optimal conditions, pyrene was mainly metabolized to 1-hydroxypyrene and gentisic acid. The structure of 1-hydroxypyrene and gentisic acid was determined by gas chromatography-mass spectrometry after identification using thin-layer chromatography.