Unknown Substance Research Articles

Calcium chloride poisoning: an autopsy case report and histologic features.

Calcium chloride, which is commonly used in de-icing agents and desiccants, is known for the potential harm it can cause through skin contact, oral ingestion, or intravenous administration. The current paper reports on an autopsy case of a 68-year-old woman who died after ingesting an unknown substance. Histopathological examination revealed coagulative necrosis in the esophagus and ionized blood calcium levels that were significantly higher than normal. Calcium chloride was detected in the contents of the water bottle collected at the scene. These results are expected to make a significant contribution to the limited literature on fatal outcomes from calcium chloride ingestion, while emphasizing the need for heightened awareness and education about the risks of commonly available chemicals.

Using nitrogen-containing organosilicon compounds in the creation of heat- and fire-resistant filling compositions to seal high-voltage and high-frequency equipment

Objectives. To study the possibility of using nitrogen-containing organosilicon compounds in the creation of heat-resistant and fireresistant casting compositions to seal high-voltage high-frequency equipment.Methods. Nitrogen-containing organosilicon compounds were obtained using the N-siloxycarbonylation, formylation, and silylation methods. The methods used in the work were infrared spectroscopy, elemental analysis, viscometry, and differential scanning calorimetry. The mechanical and dielectric properties of the samples were determined.Results. Previously unknown substances and compounds containing nitrogen-containing organosilicon products as components of the curing composition were obtained. Their physicomechanical and operational properties were examined, including the possibility of using them as filling heat-resistant and fire-resistant compositions for sealing high-voltage and high-frequency equipment.Conclusions. It was shown that nitrogen-containing organosilicon compounds — 3-(diethylamino)-2-[(triethoxysilyl)oxy]propyl-2-methacrylate and triethoxysilyl ester of γ-triethoxysilylpropyl-carbamic acid — can be used as part of a curing system together with bromine-containing fillers, in order to obtain compounds used for filling high-voltage high-frequency transformers, throttle valves, and other electronic equipment elements with non-combustible properties and increased heat resistance.

Evaluation of DSM-5 Diagnostic Criteria for Betel-Quid Use Disorder Using the Addiction Characteristics Defined by American Society of Addiction Medicine

Background The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), categorizes betel-quid use disorder (BUD) under Other (Or Unknown) Substance Use Disorder, and the diagnostic criteria used are adapted from those of Substance Use Disorder. Because different substances have different characteristics, an improved set of diagnostic criteria is required to better detect BUD. Objective The objective of this study was to examine the different measures of accuracy for DSM-5 BUD by using the addiction characteristics defined by the American Society of Addiction Medicine (ASAM). Methods A certified psychiatrist conducted face-to-face diagnostic interviews. Questionnaires were administered to assess betel-quid use history, patterns of use, and dependence features. All betel-quid users were evaluated for BUD by using the DSM-5 criteria and addiction characteristics defined by the ASAM. Results One of the DSM-5 diagnostic criteria for BUD, namely large amount of time spent on obtaining and using betel quid and recovering from betel-quid use, showed the lowest sensitivity of 0.14, lowest diagnostic accuracy of 0.63, and lowest diagnostic odds ratio of 2.61. Another DSM-5 diagnostic criterion, namely continued betel-quid use despite knowledge of physical or psychological problems, had the lowest specificity of 0.49. The diagnostic threshold of five or more DSM-5 BUD criteria showed a sensitivity of 0.86 and a specificity of 0.97. Conclusions This study is the first to evaluate the different measures of accuracy for DSM-5 BUD. Given that each addictive substance has unique addictive characteristics, the composition and number of criteria for diagnosing DSM-5 BUD must be reconsidered.

Leveraging new approach methodologies: ecotoxicological modelling of endocrine disrupting chemicals to Danio rerio through machine learning and toxicity studies

New approach methodologies (NAMs) offer information tailored to the intended application while reducing the use of animals. NAMs aim to develop quantitative structure-activity relationship (QSAR) and quantitive-Read-Across structure-activity relationship (q-RASAR) models to predict and categorize the acute toxicity of known and unknown endocrine-disrupting chemicals (EDCs) against zebrafish. EDCs are a diverse group of toxic substances that disrupt the endocrine system of humans and animals. The q-RASAR model was constructed and verified using validation metrics (R 2 = 0.886 and Q 2 = 0.814) which found to be more reliable model compare to QSAR model. The substructure fingerprint was well-fitted for the classification model and it was validated using 10-fold average accuracy (Q = 86.88%), specificity (Sp = 88.89%), Matthew’s correlation curve (MCC = 0.621) and receiver operating characteristics (ROC = 0.828). The dataset of unknown substances revealed that phenolphthalein (Php) exhibited a significant level of toxicity based on q-RASAR model. The docking and simulation study indicated that the computationally derived important features successfully bound to the target zebrafish sex hormone binding globulin (zfSHBG). The experimental LC50 value of 0.790 mg L−1 was very close to the predicted value of 0.763 mg L−1, which provides high confidence to the developed model.

Adsorption performance with field emission scanning electron microscopy of fruit peel induced Silver Nanoparticles in C16H18ClN3S for waste water treatment

There is a growing demand for cost-effective and sustainable technologies for treating wastewater as water consumption increases and conventional technologies become more expensive. Nanoparticles have a great deal of potential for use in the treatment of waste water. Their unique surface area allows them to effectively remove toxic metal ions, pathogenic microorganisms, organic and inorganic solutes from water. This study investigated the potential of orange and banana peels as renewable nano adsorbents for removing dyes and dissolved organic compounds from textile wastewater. Orange and banana peels are an optimal selection due to their favourable chemical characteristics, namely the presence of cellulose, pectic, hemicellulose, and lignin. Their capacity to adsorb diverse anionic and cationic compounds on their surface-active sites is attributed to their unique functional group compositions. Silver nanoparticles are able to adsorb heavy metals due to their exceptionally low electrical and thermal resistance and surface plasmon resonance. The samples were thoroughly characterised using field emission scanning electron microscopy (FESEM), UV–Visible spectrometry, Fourier transform infrared spectroscopy (FTIR) and XRD. The nanoparticles were prepared (10 gm,50 gm,100 gm) and subsequently introduced to the wastewater sample. The optical density values were recorded at various time points. The optical density values demonstrate a decline over the course of the experiment, with a notable decrease observed over time. The results of this study provide valuable insights into the efficacy of these natural adsorbents and their potential for sustainable water purification technologies. For the purpose of this research, high performance instrumentation methods were performed as follows:•Field emission scanning electron microscopy for surface morphology studies.•Gas chromatography-mass spectrometry (GC–MS) for analytical technique that combines gas chromatography (GC) and mass spectrometry (MS) to identify unknown substances or contaminants.•Optical density values were measured for different timings of degradation.

Step-By-Step Procedure to Identify Previously Unknown Compounds by LC-QTOF-MS Exemplified by an Intoxication With the Methaqualone Analog SL-164.

In September 2019, a 22-year-old man with a history of drug abuse presented to the hospital with altered mental status. Due to a suspected drug overdose, a blood sample taken on admission and a urine sample collected 30 h thereafter were submitted to our laboratory to test for illegal drugs, pharmaceutical substances, and designer drugs. During the routine toxicological analysis of the serum sample, morphine and phenobarbital were identified by liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). Additionally, two compounds showing identical accurate masses and isotope ratios as the designer benzodiazepine diclazepam and the benzodiazepine lormetazepam were found. However, retention times differed significantly from the expected values, and the acquired MS/MS spectra did not match the library entries of the two compounds, indicating the presence of two previously unknown substances. After further investigation, SL-164 (5-chloro-3-(4-chloro-2-methylphenyl)-2-methyl-4(3H)-quinazolinone), a methaqualone analog, which has recently emerged on the research chemical market, and its hydroxy metabolite were tentatively identified by accurate mass, isotope matching, and plausible fragmentation. However, for unequivocal confirmation and quantification, a reference standard is required. As no reference material was available by the end of 2019, SL-164 was obtained from an online shop, and its identity and purity (97.8%) were confirmed by nuclear magnetic resonance spectroscopy. The subsequent quantitative analysis revealed a concentration of 390 ng/mL SL-164 in serum. In the urine sample, the parent compound was not detected, but three suspected monohydroxylated metabolites were found. This example shows that LC-QTOF-MS is a powerful approach for the (tentative) identification of unknown compounds in biological matrices.

Life-Threatening Hypokalemic Paralysis and Prevention of Severe Rebound Hyperkalemia in a Female with Barium Poisoning: A Rare Case Report

Hypokalemic paralysis is a clinical syndrome characterized by acute flaccid paralysis with concomitant hypokalemia. Complications, such as acute respiratory failure and cardiac arrhythmias, can be fatal. If treated appropriately, the patient can recover without any sequelae. We present a rare case of life-threatening hypokalemic paralysis following the ingestion of an unknown substance. At presentation, her serum potassium concentration was 1.9 mmol/L. A review of the patient’s history confirmed the ingestion of barium chloride. She was diagnosed with acute barium poisoning characterized by high serum and urine barium levels. Aggressive potassium repletion was administered intravenously and orally. Her serum potassium concentration dropped to 1.5 mmol/L and peaked at 5.4 mmol/L following treatment. The patient achieved a complete recovery and was discharged without sequelae. Barium can competitively block the potassium inward rectifier channels and interfere with the efflux of intracellular potassium, leading to severe hypokalemia. Our report illustrates a rare presentation of acute barium intoxication and a differential diagnosis indicating hypokalemic paralysis. We also discuss the pathophysiological features and compare the clinical findings with cases of rebound hyperkalemia.

Integrated Transcriptomics-Proteomics Analysis Reveals the Response Mechanism of Morchella sextelata to Pseudodiploöspora longispora Infection.

Morels (Morchella spp.) are valuable and rare edible mushrooms with unique flavors and high nutritional value. White mold disease occurring during cultivation has seriously affected the quality and yield of morels in China. In this study, the fungus causing white mold disease in morels was isolated, purified, and identified as Pseudodiploöspora longispora by morphology and molecular biology. In addition, research has shown that P. longispora infection causes wrinkled and rupturing asci, loosened cell walls, and obvious membrane breakage accompanied by severe cytoplasmic leakage in M. sextelata. Interestingly, research has shown that infection with P. longispora can induce the production of an unknown substance in the cells of M. sextelata, which accumulates on the cell membrane, leading to membrane breakage. Furthermore, integrated transcriptomics-proteomics analysis revealed the response mechanism of M. sextelata to P. longispora infection. The results indicate that DEGs and DEPs can be significantly enriched in pathways involved in oxidoreductase activity; peroxisomes, lipid transport, and metabolism; cell wall assembly; and integral components of membranes. Further electron microscopy analysis clarified the important role of changes in the cell membrane and cell wall in the response of mycelia to biological stress. This study clarified the response mechanism of M. sextelata to P. longispora, laying a foundation for further clarifying the infection mechanism of P. longispora.

A new understanding of the regulatory mechanism by which Fe/Mn nanoparticles boost Bisphenol A removal using Comamonas testosteroni

Green synthesized iron/manganese nanoparticles (Fe/Mn NPs), acted as an exogenous promoter to enhance the lignin-degrading bacteria Comamonas testosteroni FJ17 resulting in more efficient removal of bisphenol A (BPA). Batch experiments demonstrated that removal efficiency of BPA via cells at a BPA concentration of 10 mg·L−1 increased by 20.9 % when exposed to 100 mg·L−1 Fe/Mn NPs after 48 h (93.63 %) relative to an unexposed control group (72.70 %). TEM and 3D-EEM analysis confirmed that the cell membrane thickness increased from 47 to 80 nm under Fe/Mn NPs exposure, and the TB-EPS secretion was promoted. Meanwhile, Fe/Mn NPs facilitated greater electron transfer capacity of c-cytochrome (0.55 V reduction peak) and an unknown cytochrome substance (0.7 V oxidation peak) on the surface of cells. Studies of the effect of Fe/Mn NPs on both the growth and activity of laccase cells showed that both biomass and laccase secretion increased significantly during the logarithmic growth period (6–36 h). LC-MS analysis and toxicity assessment indicated that Fe/Mn NPs decreased the degradation time of BPA and efficiently reduced the toxicity of its by-products. Transcriptomic analysis revealed 315 up-regulation of the key genes associated with energy supply, membrane translocation, and metabolic pathways upon exposure to Fe/Mn NPs. Such as MFS transporter (2.27-fold), diguanylate cyclase (1.76-fold) and protocatechuate-3,4-dioxygenase (1.62-fold). Overall, Fe/Mn NPs accelerated proliferation by enhancing metabolic capacity and nutrient transport processes, which serves to improve the efficiency of BPA removal.

Preliminary Assessment of On-Orbit Radiometric Calibration Challenges in NOAA-21 VIIRS Reflective Solar Bands (RSBs)

The National Oceanic and Atmospheric Administration (NOAA) 21 Visible Infrared Imaging Radiometer Suite (VIIRS) was successfully launched on 10 November 2022. To ensure the required instrument performance, a series of Post-Launch Tests (PLTs) were performed and analyzed. The primary calibration source for NOAA-21 VIIRS Reflective Solar Bands (RSBs) is the Solar Diffuser (SD), which retains the prelaunch radiometric calibration standard from prelaunch to on-orbit. Upon reaching orbit, the SD undergoes degradation as a result of ultraviolet solar illumination. The rate of SD degradation (called the H-factor) is monitored by a Solar Diffuser Stability Monitor (SDSM). The initial H-factor’s instability was significantly improved by deriving a new sun transmittance function from the yaw maneuver and one-year SDSM data. The F-factors (normally represent the inverse of instrument gain) thus calculated for the Visible/Near-Infrared (VISNIR) bands were proven to be stable throughout the first year of the on-orbit operations. On the other hand, the Shortwave Infrared (SWIR) bands unexpectedly showed fast degradation, which is possibly due to unknown substance accumulation along the optical path. To mitigate these SWIR band gain changes, the NOAA VIIRS Sensor Data Record (SDR) team used an automated calibration software package called RSBautoCal. In March 2024, the second middle-mission outgassing event to reverse SWIR band degradation was shown to be successful and its effects are closely monitored. Finally, the deep convective cloud trends and lunar collection results validated the operational F-factors. This paper summarizes the preliminary on-orbit radiometric calibration updates and performance for the NOAA-21 VIIRS SDR products in the RSB.

Investigation of the Effectiveness of Barrier Layers to Inhibit Mutagenic Effects of Recycled LDPE Films, Using a Miniaturized Ames Test and GC-MS Analysis

To fulfil the European Green Deal targets and implement a circular economy, there is an urgent need to increase recycling rates of packaging materials. However, before recycled materials can be used in food contact applications, they must meet high safety standards. According to the European Food Safety Authority (EFSA), a worst-case scenario must be applied and unknown substances must be evaluated as being potentially genotoxic. The Ames test, which detects direct DNA-reactive effects, together with chromatographic analysis is very promising to complement risk assessment. This study aims to evaluate the effectiveness of functional barriers in ten different samples, including virgin and recycled LDPE foils. FT-IR analysis did not show major differences between virgin and recycled films. Light microscopy revealed differences in quality and an increased number of particles. GC-MS analysis detected and quantified 35 substances, including eight unknowns. Using a miniaturized version of the Ames test, four of ten samples tested positive in two individual migrates up to a dilution of 12.5%. All virgin LDPE materials tested negative; however, recycled material F showed an increased mutagenic activity, with an n-fold induction up to 28. Samples with functional barriers lowered migration and reduced mutagenicity. Nonetheless, further investigations are needed to identify possible sources of contamination.

Monitoring of ketamine-based emerging contaminants in wastewater: a direct-injection method and fragmentation pathway study

The ketamine (KET) and its analogs consumed by humans are becoming emerging contaminants (ECs), as they at present in surface waters after being carried through wastewater systems. Drugs in wastewater can be analyzed using the direct-injection method, a simple wastewater analysis (WWA) method that can provide objective, continuous and nearly to real-time findings. This article describes an ultra-high-pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification and confirmation of seven KET-based ECs in wastewater by direct injection. After optimization of the UPLC–MS/MS and sample pretreatment conditions, the method was validated and applied to samples (n = 157) collected from several wastewater treatment plants (WWTPs) in southern China in which KET had the highest detection rate. The established direct-injection method was not only simple to perform but also had better sensitivity, shorter detection times, and analyzed more KET-based ECs than currently published methods, meeting the requirements for the monitoring and high-throughput analysis of common KET-based ECs. We also analyzed the fragmentation pathway of KET-based ECs to obtain product ion information on other unknown substances. Additional studies are needed to establish a comprehensive direct-injection screening method of ECs in wastewater on model-based assessment.

Scorpion Peptides from Buthus martensii Karsch Venom with Dual Functions: Their Pharmaceutic Potential for Cancer Pain Therapy

Abstract: Buthus martensii Karsch (BmK) scorpion venom and its extracts are compounds found to contain a mixture of peptides with antitumor and analgesic activities. The extracts also contain polypeptides, lipids, nucleotides, mucoproteins, and other unknown substances showing potential therapeutic application. Finding medically relevant toxins, a range of peptides have been purified from BmK scorpion venom. These scorpion toxins are believed to modulate pain pathways to treat pain and cancer. This study aims to review the literature on BmK scorpion peptides with dual functions, their analgesic effects, and their mechanism of action in pain treat-ments and cancer. We reviewed the literature published between 1990 and 2023 from various databases and identified 59 articles suitable for our narrative review. In 1994, the first BmK scorpion peptide with an analgesic effect was purified. Since then, more analgesic peptides have been purified, including BmK AGAP, BmK AGAP-SYPU2, BmK AGP, BmK AGP-SYPU1, BmK AGP-SYPU2, BmK AS, and BmK iT2. Studies have demonstrated that these peptides bind to voltage sodium channels and inhibit the inactivation of the activated sodium channels to block neuron transmission. The analgesic activities of these peptides have been examined on different pain stimuli, resulting in strong analgesic and antitumor effects. Moreover, the antitumor activi-ties of these peptides have been investigated in vitro and in vivo. The findings showed that the analgesic peptides may have antitumor effects. Based on their dual functions, these peptides have the potential to be developed as practical therapeutic agents for the treatment of cancer-related pain.

Non-targeted identification and risk assessment of unknown substances in disposable plastic tableware by GC-Orbitrap HRMS

Disposable plastic tableware was widely used and it was particularly important to identify potential hazardous substances in it and evaluate the risk to humans health. In this study, 85 substances were identified in 60 samples (22 bowls, 20 sporks, and 18 straws) by methanol extraction and non-targeted analysis using GC-Orbitrap HRMS. Subsequently, 14 high-risk substances were further screened and their migration in the samples was measured in three food simulants. Finally, based on the proposed safety limit assessment scheme for EU- authorized and unauthorized substances, the risk assessment of exposure to high-risk substances in disposable plastic tableware was performed for three age groups. The results showed that the dibutyl phthalate and bis(2-ethylhexyl) phthalate in some samples exceeded the safety limit value. Overall, the risk of bowls was lower than spock and straws, and the potential exposure risk for young children was higher than that of adults and older children.

Colorimetric Detection of Fentanyl Powder on Surfaces Using a Supramolecular Displacement Assay.

Fentanyl is a potent synthetic opioid with an alarmingly low lethal dosage of 2 mg. The equipment necessary to detect fentanyl in field settings (e.g., hand-held spectrometers) is restricted to highly trained, well-funded, and specialized personnel. Established point-of-need technologies, such as lateral flow immunochromatographic strips, are available; however, they often involve multiple contact-based steps (e.g., collection, mixing) that pose a higher risk to users handling unknown substances. Herein, we developed a colorimetric displacement assay capable of contactless detection of fentanyl in liquid or solid samples. The basis of our assay relies on the presence of fentanyl to displace a redox mediator, ferrocene carboxylic acid, inclusively bound in the cavity of a supramolecular host, CB[7]. The displacement is only possible in the presence of high affinity binding guests, like fentanyl (KA ∼ 106 M-1). The liberated redox guest can then react with indicator reagents that are free in solution, producing either: (i) a distinct blue color to indicate the presence of fentanyl or (ii) a pale blue tint in the absence of fentanyl. We demonstrate rapid and specific detection of fentanyl free base and fentanyl derivatives (e.g., acetyl fentanyl and furanyl fentanyl) against a panel of 9 other common drugs of abuse (e.g., morphine, cocaine, and heroin). Furthermore, we highlight the intended use of this assay by testing grains of fentanyl derivatives on a surface with a drop (i.e., 25 μL) of the assay reagent. We anticipate that this approach can be applied broadly to identify the presence of fentanyl at the point of need.

Mycotoxins and Amyotrophic Lateral Sclerosis: Food Exposure, Nutritional Implications and Dietary Solutions.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder determined by a combination of both genetic and environmental factors. Despite wide investigations, the role of chronic exposure to environmental pollutants is still rather unknown. Among natural toxins, the mycotoxins have received major attention only in the last few years, due to both technical and scientific achievements that allowed to disentangle many important features of the complex fungal biology. Whereas the effects of acute and high-dose mycotoxin exposure are well known, the potential effects of chronic and low-dose exposure on neurodegeneration have not been broadly elucidated. In this review, we have summarized all the studies concerning environmental exposure to unknown substances that caused ALS outbreaks all over the world, reinterpreting in light of the new scientific acquisitions and highlighting the potential and neglected role of mycotoxins. Then, we focused on recent papers about food exposure to mycotoxin, mycobiome and fungal infections in ALS and other neurodegenerative diseases. We analyzed the gaps of current literature that lead to an undervaluation of mycotoxins as detrimental molecules. By listing all the most important mycotoxins and analyzing all the biological pathways that they can affect, we explained the reasons why they need to be considered in the next epidemiological studies on ALS and other neurodegenerative and neuroinflammatory diseases. In conclusion, after suggesting some possible solutions to mitigate mycotoxin exposure risk, we affirm that future collaborations between scientists and policymakers are important to develop sustainable interventions and promote health through dietary diversity.

Confirmation of the composition in complex mixed pharmaceuticals by micro-synchrotron infrared spectroscopy during the investigation of a medical sea chest, c1850

A large medical sea chest was investigated to identify the composition of the various medicines contained within. During the investigation, the complex history of the chest was also revealed, from its likely use on migrant ships travelling from England to Australia to its later use on various rural properties in Victoria and New South Wales. Infrared spectroscopy (ATR-FTIR) and X-ray fluorescence spectroscopy (pXRF) were used in combination to investigate 21 medicines in the chest, to confirm labelled contents and to identify unknown substances and the composition of mixed medicines. Synchrotron micro-infrared analysis was used as well to identify individual particles in two complex mixtures (Dragons Blood and Dover’s Powder), revealing the medicines’ original formulas and the use of adulterants to extend expensive substances. Both toxic and controlled substances were identified within the sea chest, enabling the museum to develop detailed storage and handling plans to reduce the risks to collection users and to conform with legislative requirements.

Multi-Channel Hyperspectral Imaging Spectrometer Design for Ultraviolet Detection in the Atmosphere of Venus

The spectroscopic detection of SO2 and unknown UV absorber substance in the H2SO4 cloud layer of Venus’ atmosphere is currently a focal point in the study of the habitability of Venusian atmospheric clouds. This paper addresses the simultaneous detection requirements of multiple substances in the ultraviolet range of Venus’ atmosphere and proposes a multi-channel hyperspectral imaging system design using pupil separation prisms and grating multilevel spectra. The system achieves a multi-channel design by splitting the entrance pupil of the telescope using prisms. Spectra from different channels are diffracted to the same detector through different orders of the grating. The system features a single spectrometer and detector, enabling simultaneous detection of spectra from different channels. It also boasts advantages such as compact size, ultra-high spectral resolution, and simultaneous multi-channel detection. The system design results indicate that within the working spectral range of three channels, the spectral resolution is better than 0.15 nm, surpassing previous in-orbit or current in-orbit planetary atmospheric detection spectrometers. With a Nyquist frequency of 56 lp/mm, the full-field MTF exceeds 0.7. The system’s smile is less than 0.05 μm, and the keystone is less than 0.04 μm, meeting the requirements for imaging quality.

A Review of Mass Spectrometry as an Important Analytical Tool for Structural Elucidation of Biological Products

Mass spectrometry (MS) is one of the most versatile analytical measurement tools available to scientists today and finds application in virtually most aspects of chemistry research. MS is an efficient method to elucidate the structure and chemical composition of different samples or molecule. Recently, it has been used to classify biological products, in particular proteins and protein complexes, in a number of species. The success of mass spectrometry is driven both by innovative instrumentation designs, especially those operating on the time-of-flight or ion-trapping principles, and by large-scale biochemical strategies, which use mass spectrometry to detect the isolated proteins. Due to MS capability to distinguish between substances, it is used to identify unknown substances and its isotopes. When compared with other analytical tools or orthogonal methods used in analytical laboratories, mass spectrometers are often used as it has less background interference since it is performed in a vacuum. The increase in sensitivity and resolution of the MS has opened new dimensions for structural elucidation of biological products. In this review, the recent research application of MS techniques for the structural elucidation of some biological products was presented.

Toxicity Screening of Fungal Extracts and Metabolites, Xenobiotic Chemicals, and Indoor Dusts with In Vitro and Ex Vivo Bioassay Methods.

It is controversial how useful bioassays are for identifying the in vivo toxicity of hazardous environmental exposures. In this study, fruiting bodies of forest mushrooms (n = 46), indoor mold colonies (n = 412), fungal secondary metabolites (n = 18), xenobiotic chemicals such as biocides and detergents (n = 6), and methanol extracts of indoor dusts from urban buildings (n = 26) were screened with two different bioactivity assays: boar sperm motility inhibition (BSMI) and inhibition of cell proliferation (ICP) tests. For the forest mushrooms, the toxicity testing result was positive for 100% of poisonous-classified species, 69% of non-edible-classified species, and 18% of edible-classified species. Colonies of 21 isolates of Ascomycota mold fungal species previously isolated from water-damaged buildings proved to be toxic in the tests. Out of the fungal metabolites and xenobiotic chemicals, 94% and 100% were toxic, respectively. Out of the indoor dusts from moldy-classified houses (n = 12) and from dry, mold-free houses (n = 14), 50% and 57% were toxic, respectively. The bioassay tests, however, could not differentiate the samples from indoor dusts of moldy-classified buildings from those from the mold-free buildings. Xenobiotic chemicals and indoor dusts were more toxic in the BSMI assay than in the ICP assay, whereas the opposite results were obtained with the Ascomycota mold colonies and fungal secondary metabolites. The tests recognized unknown methanol-soluble thermoresistant substances in indoor settled dusts. Toxic indoor dusts may indicate a harmful exposure, regardless of whether the toxicity is due to xenobiotic chemicals or microbial metabolites.