Target, Suspect and Non-Target Screening of Silylated Derivatives of Polar Compounds Based on Single Ion Monitoring GC-MS

Gumbi, Bhekumuzi; Moodley, Brenda; Birungi, Grace; Ndungu, Patrick

doi:10.3390/ijerph16204022

Cited by 20 publications

(6 citation statements)

References 42 publications

(52 reference statements)

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“…The compounds were assigned probable identities based on similarity index (SI) value, generated from the mass spectral analyses of the test compounds and their comparison with the reference compounds listed in the NIST and Wiley library. An SI of more than 85 was considered for assignment of probable identity to the compounds [72]. Out of the total 30 peaks detected in the chromatogram, 20 peaks were specific to the culture S. californicus ADR1 while rest of the peaks were related to the production media and the solvent control ( Figure S1).…”

Section: Secondary Metabolite Profiling and Gc-ms Analysis Of Metabolmentioning

confidence: 99%

Isolation and Characterization of a New Endophytic Actinobacterium Streptomyces californicus Strain ADR1 as a Promising Source of Anti-Bacterial, Anti-Biofilm and Antioxidant Metabolites

Singh

Dubey

2020

Microorganisms

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In view of the fast depleting armamentarium of drugs against significant pathogens, like methicillin-resistant Staphylococcus aureus (MRSA) and others due to rapidly emerging drug-resistance, the discovery and development of new drugs need urgent action. In this endeavor, a new strain of endophytic actinobacterium was isolated from the plant Datura metel, which produced secondary metabolites with potent anti-infective activities. The isolate was identified as Streptomyces californicus strain ADR1 based on 16S rRNA gene sequence analysis. Metabolites produced by the isolate had been investigated for their antibacterial attributes against important pathogens: S. aureus, MRSA, S. epidermis, Enterococcus faecium and E. faecalis. Minimum inhibitory concentration (MIC90) values against these pathogens varied from 0.23 ± 0.01 to 5.68 ± 0.20 μg/mL. The metabolites inhibited biofilm formation by the strains of S. aureus and MRSA (Biofilm inhibitory concentration [BIC90] values: 0.74 ± 0.08–4.92 ± 0.49 μg/mL). The BIC90 values increased in the case of pre-formed biofilms. Additionally, the metabolites possessed good antioxidant properties, with an inhibitory concentration (IC90) value of 217.24 ± 6.77 µg/mL for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging. An insight into different classes of compounds produced by the strain ADR1 was obtained by chemical profiling and GC-MS analysis, wherein several therapeutic classes, for example, alkaloids, phenolics, terpenes, terpenoids and glycosides, were discovered.

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Section: Secondary Metabolite Profiling and Gc-ms Analysis Of Metabolmentioning

confidence: 99%

Isolation and Characterization of a New Endophytic Actinobacterium Streptomyces californicus Strain ADR1 as a Promising Source of Anti-Bacterial, Anti-Biofilm and Antioxidant Metabolites

Singh

Dubey

2020

Microorganisms

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“…Water and sediments samples were collected along Mgeni and Msunduzi rivers located in Kwa-Zulu Natal, South Africa (Figure 1) (Gumbi et al, 2019). These two rivers pass through towns, agricultural fields, wastewater effluent discharge sites, landfills, hospitals, and villages.…”

Section: Samplingmentioning

confidence: 99%

“…A preliminary risk characterization in the different environmental compartments was based on a tiered system FIGURE 1 | Sampling area of the Mgeni and Msunduzi rivers in KwaZulu-Natal, South Africa. Grab samples were collected at all points and using the developed method described in this work (map was drawn using GIS software shapefile) (Gumbi et al, 2019).…”

Section: Risk Assessmentmentioning

confidence: 99%

“…Therefore, their isolation at different pH values needed to be optimized. The aqueous distribution of compounds was investigated using water adjusted at three different pH values (2, 7, and 9) with HCl or NaOH as shown in (Gumbi et al, 2017a(Gumbi et al, ,b, 2019. Spiked double distilled water (10 µg L −1 ), aliquots of 200 ml, adjusted to pH 2, 7, and 9 were passed through Oasis HLB at flow rates between 5 and 8 ml min −1 .…”

Section: Sample Preparationmentioning

confidence: 99%

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Risk Assessment of Personal Care Products, Pharmaceuticals, and Stimulants in Mgeni and Msunduzi Rivers, KwaZulu-Natal, South Africa

et al. 2022

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In this work, environmental occurrence and risk assessment of pharmaceuticals, personal care products (PPCPs), and stimulants are presented. A quantitative technique is described for ultrasonic-assisted solid-phase extraction (SPE) followed by GC-MS after derivatization of PPCPs; propylparaben, triclosan, carbamazepine, chloramphenicol, and stimulant caffeine. Ultrasonic-assisted extraction together with centrifugation were used to extract sediment samples collected from the Mgeni and Msunduzi rivers. An SPE procedure was used for cleanup and to concentrate selected compounds from diluted aqueous extracts. The final extracts were derivatized and analyzed with GC-MS in selected ion monitoring (SIM) mode. The recoveries of the analytes ranged from 66 to 108%. The method detection limits were (0.08–1.82 ng g−1 for solid and 0.08–10 μg L−1 for liquid) and quantification limits (0.42–5.51 ng g−1 for solid and 0.25–25 μg L−1 for liquid). The optimized method was applied in the evaluation of two rivers over 3 months in KwaZulu-Natal, South Africa. All targeted compounds were present in the environment at concentration levels between not detected to 174 ng g−1 and not detected to 30 μg L−1 for solids and aqueous environmental samples, respectively. A comparison of predicted no environmental effect concentration (PNECs) with measured environmental concentration (MECs) showed that these PPCPs present a high ecological risk to the receiving environment (agricultural lands and households). Our work is close to reality because we used MECs as opposed to using predicted environmental concentration (PECs) values, which are normally calculated from consumption, production of compound per year, and various estimated factors.

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“…The chemical modification of analytes for enhancing their detection and analysis by various analytical methods is common practice in analytical and forensic laboratories [1,2]. These chemical modifications are a cornerstone component particularly in the realm of gas chromatography-mass spectrometry (GC-MS), wherein polar compounds are specifically modified to yield derivatives possessing superior volatility and chromatographic profiles relative to the starting, unmodified analyte [3].…”

Section: Introductionmentioning

confidence: 99%

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI‐GC–MS and LC‐HRMS in official OPCW proficiency test matrices

Valdez,

Kaseman,

Dreyer

et al. 2024

Journal of Forensic Sciences

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Pinacolyl alcohol (PA), a key forensic marker for the nerve agent Soman (GD), is a particularly difficult analyte to detect by various analytical methods. In this work, we have explored the reaction between PA and 1,1′‐carbonyldiimidazole (CDI) to yield pinacolyl 1H‐imidazole‐1‐carboxylate (PIC), a product that can be conveniently detected by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography‐high‐resolution mass spectrometry (LC‐HRMS). Regarding its GC–MS profile, this new carbamate derivative of PA possesses favorable chromatographic features such as a sharp peak and a longer retention time (RT = 16.62 min) relative to PA (broad peak and short retention time, RT = 4.1 min). The derivative can also be detected by LC‐HRMS, providing an avenue for the analysis of this chemical using this technique where PA is virtually undetectable unless present in large concentrations. From a forensic science standpoint, detection of this low molecular weight alcohol signals the past or latent presence of the nerve agent Soman (GD) in a given matrix (i.e., environmental or biological). The efficiency of the protocol was tested separately in the analysis and detection of PA by EI‐GC–MS and LC‐HRMS when present at a 10 μg/mL in a soil matrix featured in the 44th PT and in a glycerol‐rich liquid matrix featured in the 48th Official Organization for the Prohibition of Chemical Weapons (OPCW) Proficiency Test when present at a 5 μg/mL concentration. In both scenarios, PA was successfully transformed into PIC, establishing the protocol as an additional tool for the analysis of this unnatural and unique nerve agent marker by GC–MS and LC‐HRMS.

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Target, Suspect and Non-Target Screening of Silylated Derivatives of Polar Compounds Based on Single Ion Monitoring GC-MS

Cited by 20 publications

References 42 publications

Isolation and Characterization of a New Endophytic Actinobacterium Streptomyces californicus Strain ADR1 as a Promising Source of Anti-Bacterial, Anti-Biofilm and Antioxidant Metabolites

Isolation and Characterization of a New Endophytic Actinobacterium Streptomyces californicus Strain ADR1 as a Promising Source of Anti-Bacterial, Anti-Biofilm and Antioxidant Metabolites

Risk Assessment of Personal Care Products, Pharmaceuticals, and Stimulants in Mgeni and Msunduzi Rivers, KwaZulu-Natal, South Africa

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI‐GC–MS and LC‐HRMS in official OPCW proficiency test matrices

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