Alkaline Hydrolysis Research Articles

Removal of Cr(VI) from Wastewater Using Acrylonitrile Grafted Cellulose Extracted from Sugarcane Bagasse.

A highly efficient low-cost adsorbent was prepared using raw and chemically modified cellulose isolated from sugarcane bagasse for decontamination of Cr(VI) from wastewater. First, cellulose pulp was isolated from sugarcane bagasse by subjecting it to acid hydrolysis, alkaline hydrolysis and bleaching with sodium chlorate (NaClO3). Then, the bleached cellulose pulp was chemically modified with acrylonitrile monomer in the presence Fenton's reagent (Fe+2/H2O2) to carry out grafting of acrylonitrile onto cellulose by atom transfer radical polymerization. The developed adsorbent (acrylonitrile grafted cellulose) was analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Both raw cellulose and acrylonitrile grafted cellulose were used for chromium removal from wastewater. The effects of metal ion concentration, pH, adsorbent dose and time were studied, and their values were optimized. The optimum conditions for the adsorption of Cr(VI) onto raw and chemically modified cellulose were: metal ion concentration: 50 ppm, adsorbent dose: 1 g, pH: 6, and time: 60 min. The maximum efficiencies of 73% and 94% and adsorption capacities of 125.95 mg/g and 267.93 mg/g were achieved for raw and acrylonitrile grafted cellulose, respectively. High removal efficiency was achieved, owing to high surface area of 79.92 m2/g and functional active binding cites on grafted cellulose. Isotherm and kinetics studies show that the experimental data were fully fitted by the Freundlich isotherm model and pseudo first-order model. The adsorbent (acrylonitrile grafted cellulose) was regenerated using three different types of regenerating reagents and reused thirty times, and there was negligible decrease (19%) in removal efficiency after using it for 30 times. Hence, it is anticipated that acrylonitrile could be utilized as potential candidate material for commercial scale Cr(VI) removal from wastewater.

DEGRADATION ESTIMATION OF ROSUVASTATIN CALCIUM IN PHARMACEUTICAL TABLET FORMULATION

Objectives: The present objective was to undertaken the Rosuvastatin Calcium degradation in the tablets formulations with a rapid, economic, consistent, specific and simple analytical procedure. Methods: The analytical RP-HPLC was validated with mobile phase composition of methyl alcohol : cyanomethane : water (45:35:20,v/v). The detection was achieved with a flow 1.0 ml/min by using octylsilane column (250 x 4.6 mm, 5 µ), at 248 nm. Results: The established analytical procedure of Rosuvastatin Calcium was validated statistically for reproducibility, accuracy, specificity as per ICH-guideline. The correlation coefficient was 0.999 with the linearity concentration range 140-260 µg/ml. The percentage recovery was achieved 99.86 to 106.12 and RSD% of precision was 0.599. The specificity was confirmed by excellent photolytic and thermal stability of Rosuvastatin Calcium. The degradation statistical recovery of Rosuvastatin Calcium in dry, wet and thermal stage ware 99.25%, 99.52 % and 99.64% respectively validated. The developed peaks in the chromatograms of alkali, oxidation and acid decomposition of Rosuvastatin Calcium were confirmed by screening the degradation peaks and the recovery percentage were found 23.16 %, 85.59 % and 66.33 % respectively. Conclusions: The stress conditions of Rosuvastatin Calcium in degradation study is successfully developed and it is also important in stability to determined the highest lipid lowering agent in the body that block the manufacturing of cholesterol. The stress conditions like in aqueous acidic hydrolysis, oxidative, alkaline hydrolysis, thermal and photolytic degradation study was validated with a simple, cost efficient, linear, accurate, selective, specific, high performance liquid chromatography with a simple effortless mobile phase containing methyl alcohol, cyanomethane and water.

Alkaline hydrolysis of poly (ethylene terephthalate) using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)

Advanced polymer recycling methods can address challenges with mechanical recycling caused by contaminated samples and mixed plastic wastes. In this work, we report alkaline hydrolysis of poly (ethylene terephthalate) (PET) flakes using a super basic reagent, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) in an aqueous media. The effect of operating conditions including temperature, time, and DBU concentration on the conversion of PET and the yield of terephthalic acid (TPA) was investigated. The relative hydrolysis kinetics were compared for the homogenous reaction of ethyl acetate and heterogenous PET reaction to elucidate the mechanism. While DBU exhibited much higher activity for both systems than NaOH at similar conditions, the increase in rate kinetics was much greater for the PET hydrolysis. This difference in kinetics was attributed to a combination of improved surface wetting of PET by DBU reaction media and the increased activity of the DBU. The hydrolysis of ethyl acetate was studied as a model system to determine the reactant's activity in a homogenous hydrolysis reaction. The effect of surface wetting was studied by conducting contact angle measurements of solutions.

Enhancing Cutin Extraction Efficiency from Industrially Derived Tomato Processing Residues by High-Pressure Homogenization.

This study primarily aimed to enhance the extraction of cutin from industrial tomato peel residues. Initially, the conventional extraction process was optimized using response surface methodology (RSM). Subsequently, high-pressure homogenization (HPH) was introduced to improve extraction efficiency and sustainability. The optimization process focused on determining the optimal conditions for conventional extraction via chemical hydrolysis, including temperature (100-130 °C), time (15-120 min), and NaOH concentration (1-3%). The optimized conditions, determined as 130 °C, 120 min, and 3% NaOH solution, yielded a maximum cutin extraction of 32.5%. Furthermore, the results indicated that applying HPH pre-treatment to tomato peels before alkaline hydrolysis significantly increased the cutin extraction yield, reaching 46.1%. This represents an approximately 42% increase compared to the conventional process. Importantly, HPH pre-treatment enabled cutin extraction under milder conditions using a 2% NaOH solution, reducing NaOH usage by 33%, while still achieving a substantial cutin yield of 45.6%. FT-IR analysis confirmed that cutin obtained via both conventional and HPH-assisted extraction exhibited similar chemical structures, indicating that the main chemical groups and structure of cutin remained unaltered by HPH treatment. Furthermore, cutin extracts from both conventional and HPH-assisted extraction demonstrated thermal stability up to approximately 200 °C, with less than 5% weight loss according to TGA analysis. These findings underscore the potential of HPH technology to significantly enhance cutin extraction yield from tomato peel residues while utilizing milder chemical hydrolysis conditions, thereby promoting a more sustainable and efficient cutin extraction process.

Identification and characterization of organic and glycosidic acids in the crude resin glycoside fraction of Ipomoea alba seeds

Resin glycosides act as laxatives in crude drugs derived from plants of the Convolvulaceae family. These compounds have exhibited antibacterial, ionophoric, anti-inflammatory, antiviral, and multidrug resistance-modulating properties, as well as cytotoxicity against cancer cells. This study investigated the organic acid, hydroxyl fatty acid, monosaccharide, and glycosidic acid components of the crude resin glycoside fraction obtained from the methanol extract of Ipomoea alba L. (Convolvulaceae) seeds, which was subjected to alkaline and acidic hydrolysis. The alkaline hydrolysis yielded acetic, isobutyric, (E)-2-methylbut-2-enoic, and 2S-methyl-3S-hydroxybutyric acids as organic acid components, along with a glycosidic acid fraction. The acidic hydrolysis of the glycosidic acid fraction resulted in the isolation of 11S-hydroxytetradecanoic and 11S-hydroxyhexadecanoic acids as hydroxyl fatty acid components, as well as d-glucose, d-quinovose, d-fucose, d-xylose, and l-rhamnose as monosaccharide components. In addition, 10 new glycosidic acid methyl esters were isolated from the glycosidic acid fraction treated with trimethylsilyldiazomethane–hexane, along with one known glycosidic acid methyl ester. Of these, eight compounds contained new glycans. Four of these compounds were unusual natural glycosides with four glycosidic linkages to one monosaccharide. Their structures were determined using MS and NMR spectral analyses, which provided valuable insights into the unique glycosidic composition of I. alba seeds.

Soluble and hydrolyzable phenolic compounds in date fruits (Phoenix dactylifera L.) by UPLC-QTOF-MS/MS and UPLC-DAD

Phenolic compounds in plant foods exist in soluble, hydrolyzable, and insoluble forms. This study is the first to analyze both soluble (extracted using 80 % methanol) and hydrolyzable (extracted using ethyl acetate after alkaline hydrolysis) phenolics in 18 date cultivars. The phenolic compounds were identified and quantified using ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry and diode array detectors. A total of 59 peaks were detected, of which 45 were identified while 14 remained unidentified. The concentrations of the soluble and hydrolyzable phenolics ranged from 27.5–54.0 and 24–78.5 mg/100 g fresh weight, respectively. Gallic acid and ferulic acid predominated in the soluble and hydrolyzable fractions, quercetin and taxifolin were predominant in the soluble fraction, while caffeic acid and chlorogenic acid were abundant in the hydrolyzable fraction. The hydrolyzable phenolics were found to contribute significantly to the total phenolic content of date fruits pointing to the need to include them in the analysis of total phenolic compounds in foods.

Validation of HPLC-DAD method for analysis of paracetamol and potassium sorbate in liquid oral formulations and its application to forced degradation study

AbstractDue to the frequent use of paracetamol formulations, it is useful to develop an analytical technique for the determination of intact paracetamol in presence of other drugs and excipients or the degradation products. In this study, a simple, isocratic, fast, specific, accurate and precise stability-indicating high performance liquid chromatography (HPLC) method has been developed and validated for simultaneous quantitative determination of paracetamol (PCM) and potassium sorbate (PS) in oral liquid formulations. The chromatographic separation was achieved on Zorbax SB C18 column (150 × 4.6 mm, 5 µm) with Zorbax SB C18 precolumn (12.5 × 4.6 mm, 5 µm) using distilled water pH 2 with ortho-phosphoric acid and acetonitrile (70:30, v/v) as a mobile phase, and UV detection at 235 nm. The temperature of the column was kept constant at 25 °C. The method was validated according to International Conference on harmonization (ICH) guidelines. The method demonstrated excellent linearity, with a correlation coefficient of 0.9996 and 0.9998 for PCM and PS, respectively, over the concentration ranges of 10–600 μg mL−1 (PCM) and 6–500 μg mL−1 (PS). The retention time was found to be 1.98 and 4.86 min for PCM and PS, respectively. Oral liquid formulation samples were subjected to various stress conditions (acidic and alkaline hydrolysis, as well as oxidative, heat and photolytic degradation) for the purpose of forced degradation study. The major degradation of paracetamol was achieved in acidic and basic stress conditions, while thermal and photolytic degradation generally had the least influence. On the other hand, potassium sorbate was highly susceptible to photolytic degradation. It was also shown that the formulation has strong influence on stability of tested compounds. Forced degradation studies demonstrated the stability-indicating power of the method and can be used to assess the stability of paracetamol and potassium sorbate in oral liquid formulations.

Induced Aggregation, Solvent Regulation, and Supracluster Assembly of Aluminum Oxo Clusters.

ConspectusRecent years have witnessed the development of cluster materials as they are atomically precise molecules with uniform size and solution-processability, which are unattainable with traditional nanoparticles or framework materials. The motivation for studying Al(III) chemistry is not only to understand the aggregation process of aluminum in the environment but also to develop novel low-cost materials given its natural abundance. However, the Al-related clusters are underdeveloped compared to the coinage metals, lanthanides, and transition metals. The challenge in isolating crystalline compounds is the lack of an effective method to realize the controllable hydrolysis of Al(III) ions. Compared with the traditional hydrolysis of inorganic Al(III) salts in highly alkaline solutions and hydrolysis of aluminum trialkyl compounds conducted carefully in an inert operating environment, we herein developed an effective way to control the hydrolysis of aluminum isopropanol through an alcoxalation reaction. By solvothermal/low melting point solid melting synthesis and using "ligand aggregation, solvent regulation, and supracluster assembly" strategies, our laboratory has established an organic-inorganic hybrid system of aluminum oxo clusters (AlOCs). The employment of organic ligands promotes the aggregation and slows the hydrolysis of Al(III) ions, which in turn improves the crystallization process. The regulation of the structure types can be achieved through the selection of ligands and the supporting solvents. Compared with the traditional condensed polyoxoaluminates, we successfully isolated a broad range of porous AlOCs, including aluminum molecular rings and Archimedes aluminum oxo cages. By studying ring expansion, structural transformation, and intermolecular supramolecular assembly, we demonstrate unique and unprecedented structural controllability and assembly behavior in cluster science. The advancement of this universal synthetic method is to realize materials customization through modularly oriented supracluster assembly. In this Account, we will provide a clear-cut definition and terminology of "ligand aggregation, solvent regulation, and supracluster assembly". Then we will discuss the discovery in this area by using a strategy, such as aluminum molecular ring, ring size expansion, ring supracluster assembly, etc. Furthermore, given the internal and external pore structures, as well as the solubility and modifiability of the AlOCs, we will demonstrate their potential applications in both the solid and liquid phases, such as iodine capture, the optical limiting responses, and dopant in polymer dielectrics. The strategy herein can be applied to extensive cluster science and promote the research of main group element chemistry. The new synthetic method, fascinating clusters, and unprecedented assembly behaviors we have discovered will advance Al(III) chemistry and will also lay the foundation for functional applications.

Improving the production of carbamoyltobramycin by an industrial Streptoalloteichus tenebrarius through metabolic engineering

Tobramycin is an essential and extensively used broad-spectrum aminoglycoside antibiotic obtained through alkaline hydrolysis of carbamoyltobramycin, one of the fermentation products of Streptoalloteichus tenebrarius. To simplify the composition of fermentation products from industrial strain, the main byproduct apramycin was blocked by gene disruption and constructed a mutant mainly producing carbamoyltobramycin. The generation of antibiotics is significantly affected by the secondary metabolism of actinomycetes which could be controlled by modifying the pathway-specific regulatory proteins within the cluster. Within the tobramycin biosynthesis cluster, a transcriptional regulatory factor TobR belonging to the Lrp/AsnC family was identified. Based on the sequence and structural characteristics, tobR might encode a pathway-specific transcriptional regulatory factor during biosynthesis. Knockout and overexpression strains of tobR were constructed to investigate its role in carbamoyltobramycin production. Results showed that knockout of TobR increased carbamoyltobramycin biosynthesis by 22.35%, whereas its overexpression decreased carbamoyltobramycin production by 10.23%. In vitro electrophoretic mobility shift assay (EMSA) experiments confirmed that TobR interacts with DNA at the adjacent tobO promoter position. Strains overexpressing tobO with ermEp* promoter exhibited 36.36% increase, and tobO with kasOp* promoter exhibited 22.84% increase in carbamoyltobramycin titer. When the overexpressing of tobO and the knockout of tobR were combined, the production of carbamoyltobramycin was further enhanced. In the shake-flask fermentation, the titer reached 3.76 g/L, which was 42.42% higher than that of starting strain. Understanding the role of Lrp/AsnC family transcription regulators would be useful for other antibiotic biosynthesis in other actinomycetes.Key points• The transcriptional regulator TobR belonging to the Lrp/AsnC family was identified. • An oxygenase TobO was identified within the tobramycin biosynthesis cluster.• TobO and TobR have significant effects on the synthesis of carbamoyltobramycin.

DNA-functionalized MOF fluorescent probes for the enzyme-free and pretreatment-free detection of MicroRNA in serum

MicroRNA (miRNA) is a promising biomarker that plays an important role in various biomedical applications, especially in cancer diagnosis. However, the current miRNA detection technology has inherent limitations such as complex operation, expensive testing cost and excessive detection time. In this study, a dual signal amplification biosensor based on DNA-functionalized metal–organic frameworks (MOFs) fluorescent probes, MFPBiosensor, was established for the enzyme-free and pretreatment-free detection of the colon cancer (CC) marker miR-23a. DNA-functionalized MOFs NH2-MIL-53(Al) (DNA@MOFs) were synthesized as fluorescent probes with specific recognition functions. A single DNA@MOF carries a large number of fluorescent ligands 2-aminoterephthalic acid (NH2–H2BDC), which can generate strong fluorescence signals after alkaline hydrolysis. Combined with catalyzed hairpin assembly (CHA), an efficient isothermal amplification technique, the dual signal enhancement strategy reduced matrix interference and sensitized the signal response. The established MFPBiosensor successfully detected extremely low levels of miRNA in complex biological samples with acceptable sensitivity and specificity. With a single detection cost of $0.583 and a test time of 50 min, the excellent inexpensive and rapid advantage of the MFPBiosensor is highlighted. More importantly, the subtle design enables the MFPBiosensor to achieve convenient batch detection, where miRNA in serum can be directly detected without any pretreatment process or enzyme. In conclusion, MFPBiosensor is a promising biosensor with substantial potential for commercial miRNA detection and clinical diagnostic applications of CC.

Veterinary antibiotics and metals impact the mass, composition and hydrolysis of biomass cultivated in piggery wastewater treatment photobioreactors

Photobioreactors are a promising alternative for piggery wastewater treatment which allows to produce valuable biomass, but the presence of antibiotics or heavy metals in the pig manure can influence the biomass composition and the posterior valorization processes. This study evaluates the effect of these pollutants on mass, composition and hydrolysis yields of the consortia of microalgae and bacteria obtained in a 1280 L photobioreactor treating pig manure. The photobioreactor feed was doped with 1) veterinary antibiotics; 2) copper, zinc, and arsenic; and 3) combination of both pollutants. The pollutants presence decreased the mass of biomass grown in the photobioreactor by up to 35% while glucose content of the biomass by up to 42% and increased protein and xylose by 30% and 16% due to oxidative stress. Likewise, they increased the protein solubilization yield by acid hydrolysis at 120 ºC by 32% while reduced glucose solubilization by 49% after alkaline hydrolysis at 120 ºC. Applying enzymatic hydrolysis and ultrasound assisted enzymatic extractions, glucose and xylose recoveries were drastically reduced in presence of heavy metals (∼100%). Antibiotics increased xylose solubilization by ultrasonication (74%), but also its degradation, decreasing xylose recovery. Thus, the presence of all these pollutants in pig manure affected biomass production and valorization and these results must be considered for biorefinery processes.

Identification and structural characterization of potential degradation products of baricitinib using liquid chromatography combined with quadrupole time-of-flight mass spectrometry

AbstractBaricitinib (BRT) is a drug substance with potent anti-inflammatory activity indicated in rheumatoid arthritis, atopic dermatitis, severe alopecia areata and recently for the treatment of Covid-19. Process impurities of the drug during its formulation are quite known, however studies regarding its degradation products (DPs) under stress conditions are limited. In this study, the drug was subjected to forced degradation under various degradation conditions, including acidic hydrolysis, alkaline hydrolysis, oxidative and thermal, to determine its inherent stability. To this purpose, a novel HPLC method was developed for the determination of degradation impurities of BRT. Alkaline hydrolysis test showed a selectivity towards breaking C–C bonds. This resulted to five DPs formed by chain scission reactions occurred at the pyrrolo-pyrimidine group between C6–C10 and C8–C9. Also, the ethylsulfonyl-azetidin-ylidene group was subjected to C–C bond cleavage at C12–C15 and C16–C18. Degradation products were further characterized with the use of liquid chromatography quadrupole time of flight tandem mass spectrometry (LC-Q-TOF-MS/MS).

Bioactive Potential of Olive Mill Waste Obtained from Cultivars Grown in the Island of Malta.

This study explores the bioactive potential of olive mill waste derived from cultivars grown in the Maltese Islands through various analytical approaches. Cell culture, cell staining, allelopathic assays, shrimp brine lethality assays, and HPLC analysis were conducted to assess the efficacy and bioactivity of the extracts using different treatments, including methanolic extraction, acid, and alkaline hydrolysis. Notably, the results from cell lines revealed that NB4r2 cells exhibited high susceptibility to the tested extracts, with the lowest IC50 recorded after 72 h of exposure. Notably, the 'Bajda' cultivar displayed the most effectiveness, particularly with acid hydrolysis. In allelopathic assays, higher concentrations of 'Malti', 'Bidni', and 'Bajda' extracts significantly inhibited lettuce seed germination. Similarly, in the brine shrimp lethality assay, higher concentrations led to increased mortality rates of Artemia salina, though rates decreased at lower concentrations. The identification of phenolic compounds found in olive mill waste was conducted using high-performance liquid chromatography (HPLC) with the use of internal standards. The identification revealed a variety of compounds, with 3-hydroxytyrosol and oleacein being present in high abundance in nearly all hydrolyzed and methanolic extracts, whereas gallic acid was found to be the least abundant. These findings highlight the rich bioactive potential of olive mill waste and provide insights into its applications in pharmaceuticals, nutraceuticals, and agriculture, emphasizing the importance of further research to fully exploit these valuable resources.

Structural elucidation, binding sites exploration and biological activities of bound phenolics from Radix Puerariae Thomsonii

Radix puerariae thomsonii (RPT) contains many phenolics and exhibits various health benefits. Although the free phenolics in RPT have been identified, the composition and content of bound phenolics, which account for approximately 20% of the total phenolic content, remain unknown. In this study, 12 compounds were isolated and identified from RPT-bound phenolic extracts, of which 2 were novel and 6 were reported first in RPT. ORAC and PSC antioxidant activities of 12 compounds, as well as their effects on alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), α-glucosidase, and α-amylase were evaluated. Genistein exhibited the highest ORAC activity, while daidzin demonstrated superior PSC activity. Five compounds, including two new compounds, exhibited the ability to activate both ADH and ALDH. All the compounds except 4-hydroxyphenylacetic acid methyl ester and 2,4,4′-trihydroxydeoxybenzoin demonstrated inhibitory effects on α-glucosidase and α-amylase. Alkaline hydrolysis and stepwise enzymatic hydrolysis revealed that bound phenolics in RPT mainly exist within starch.

Phytochemical Profile and Bioactivity of Bound Polyphenols Released from Rosa roxburghii Fruit Pomace Dietary Fiber by Solid-State Fermentation with Aspergillus niger.

This study aimed to investigate the phytochemical profile, bioactivity, and release mechanism of bound polyphenols (BPs) released from Rosa roxburghii fruit pomace insoluble dietary fiber (RPDF) through solid-state fermentation (SSF) with Aspergillus niger. The results indicated that the amount of BPs released from RPDF through SSF was 17.22 mg GAE/g DW, which was significantly higher than that achieved through alkaline hydrolysis extraction (5.33 mg GAE/g DW). The BPs released through SSF exhibited superior antioxidant and α-glucosidase inhibitory activities compared to that released through alkaline hydrolysis. Chemical composition analysis revealed that SSF released several main compounds, including ellagic acid, epigallocatechin, p-hydroxybenzoic acid, quercetin, and 3,4-dihydroxyphenylpropionic acid. Mechanism analysis indicated that the disruption of tight structure, chemical bonds, and hemicellulose was crucial for the release of BPs from RPDF. This study provides valuable information on the potential application of SSF for the efficient release of BPs from RPDF, contributing to the utilization of RPDF as a functional food ingredient.

Mn-modified bamboo biochar improves soil quality and immobilizes heavy metals in contaminated soils

Soil contamination by heavy metals is becoming increasingly serious and needs to be solved urgently. Modified biochar is an effective strategy to solve this problem, and previous studies have only focused on the remediation of single heavy metal contaminated soils through biochar. However, the effects of metal-modified bamboo biochar on soil improvement and the passivation of heavy metals are still unknown. In this study, the Mn-modified bamboo biochar was prepared and the effects of Mn-modified bamboo biochar on soil improvement and the passivation of heavy metals were investigated. The results showed that Mn-modified bamboo biochar can improve the physical and chemical properties of soil, and immobilize heavy metals (i.e., Pb, As, Cd, and Cu). After adding Mn-modified bamboo biochar, soil pH decreased by 0.08–0.70, organic matter content increased by 8.00–45.13%, and alkaline hydrolysis nitrogen content increased by 1.84–5.78%. The diethylene triamine penta-acetic acid (DTPA)-extractable Pb, As, Cd, and Cu decreased by 21.25–58.65%, 7.76–34.02%, 36.44–46.50%, and 3.13–35.21%, respectively, while the acid-extractable Pb, As, Cd, and Cu decreased by 27.81–43.31%, 23.91–26.01%, 17.56–50.60%, and 7.94–18.09% respectively. These results indicated that Mn-modified bamboo biochar can improve the physicochemical properties of the soil and effectively inactivate multi-heavy metals in contaminated soil, Mn-modified bamboo biochar is a potential alternative agent for the management of multi-heavy metal contaminated soils.

Alkaline hydrolysis and respect for the dead: an ethical critique

ABSTRACT Alkaline hydrolysis is an increasingly popular method of disposing of human corpses, which involves dissolving them into a solution of 95% water and 5% alkali, producing some bone residue and a liquid waste that can be flushed into the sewer system or otherwise hygienically disposed of. Favoured particularly by environmentalists for its perceived ecological advantages over traditional methods of inhumation and cremation, alkaline hydrolysis has been charged by some critics with being insufficiently respectful of the human corpse, and by implication the living human being whose body it once was. Following a discussion of the idea of respect for the dead and its cultural variability, it is argued that alkaline hydrolysis breaches no fundamental principles of respect for the deceased or their remains and that worries on this score are based on misunderstanding or prejudice. The question is raised whether alkaline hydrolysis might nevertheless be considered less respectful to the dead than traditional methods of burial and cremation. Three prima facie reasons in support of this claim are weighed and rejected. It is concluded that there are no sound objections based on considerations of human dignity to the adoption of alkaline hydrolysis as a disposal method for human bodies.

Production of Vanillin from Pineapple Peels Using Alkaline Hydrolysis and Microbial Fermentation

Vanillin is one of the most commonly utilized aromatic flavoring chemicals in the food and cosmetics industries. It is derived from natural sources, making it more expensive than synthetic vanillin, and it constitutes less than one percent of the annual market demand. Pineapple peel stands out as a valuable source for extracting ferulic acid, which in turn is utilized in the synthesis of vanillin. As a result, researchers are exploring alternative methods for producing vanillin, such as biotechnological production from ferulic acid. In this study, the capability of pineapple peels as a substrate for the microbial fermentation of ferulic acid by Aspergillus niger to produce vanillin in a single step was investigated. The biotransformation of ferulic acid from pineapple peel by alkaline hydrolysis was optimized using different concentrations of NaOH. Further, the detection and quantification of vanillin and ferulic acid were carried out using High-Performance Liquid Chromatography and thiobarbituric acid (TBA) method. Through HPLC analysis, the amount of vanillin concentration produced from the supernatant culture was 1.47±0.24 µg/ml from 1.0 M NaOH concentration and 2.83±0.44 µg/ml from 2.0 M NaOH concentration. From this study, 57.09±1.84 µg/ml and 83.84±4.01 µg/ml of ferulic acid were produced from the 1.0 M NaOH and 2.0M NaOH, respectively. In addition, using the TBA technique, vanillin concentrations were calculated, resulting in 12.92 ± 0.54 µg/ml and 15.38 ± 0.77 µg/ml from 1.0 M and 2.0 M NaOH concentrations, respectively. Briefly, the pineapple peel has been discovered as a good source for vanillin production using Aspergillus niger in the fermentation method.

Removal of heavy metal ions from water using nanocellulose-based membranes derived from macroalgae Chara corallina

Chara corallina is a freshwater macroalgae found in aquatic-terrestrial boundary environments. Their cellulose fibers have a crystallinity and biosynthesis similar to those of terrestrial plants. The algal nanocellulose (NC) was prepared through a series of chemical treatments, including alkaline, bleaching, grinding, and acid hydrolysis. The X-ray diffraction (XRD) crystallinity index of nanocellulose was 85.64%. The cellulose nanocrystals are seen in the form of nanorods, and the specific surface area of the sample of NC found was 5.823 m2g-1. The study aimed to test the effectiveness of a nanocellulose composite membrane in removing heavy metal ions, specifically cadmium (Cd), nickel (Ni), and lead (Pb) ions, from an aqueous solution. A vacuum filtration unit was used for the experiment, where up to five filter layers of composite membranes were examined for their ability to remove heavy metal ions. The results showed that the highest removal rates of Cd2+, Ni2+, and Pb2+ ions were 98.20%, 95.15%, and 93.80%, respectively, when using five layers of membranes of NC with the adsorbent dose set at 20 ppm. Cellulose and its derivatives are essential in sustainable technology for wastewater treatment, as they demonstrate exceptional performance in removing various types of pollutants, including heavy metals, dyes, and other pollutants. Cellulose is preferred due to its low cost, biodegradability, eco-friendliness, and simple surface modification.

Hydrolysis of riboflavins in root exudates under iron deficiency and alkaline stress

Riboflavins are secreted under iron deficiency as a part of the iron acquisition Strategy I, mainly when the external pH is acidic. In plants growing under Fe-deficiency and alkaline conditions, riboflavins have been reported to accumulate inside the roots, with very low or negligible secretion. However, the fact that riboflavins may undergo hydrolysis under alkaline conditions has been so far disregarded. In this paper, we report the presence of riboflavin derivatives and products of their alkaline hydrolysis (lumichrome, lumiflavin and carboxymethylflavin) in nutrient solutions of Cucumis sativus plants grown under different iron regimes (soluble Fe-EDDHA in the nutrient solution, total absence of iron in the nutrient solution, or two different doses of FeSO4 supplied as a foliar spray), either cultivated in slightly acidic (pH 6) or alkaline (pH 8.8, 10 mM bicarbonate) nutrient solutions. The results show that root synthesis and exudation of riboflavins is controlled by shoot iron status, and that exuded riboflavins undergo hydrolysis, especially at alkaline pH, with lumichrome being the main product of hydrolysis.