Current Analytical Chemistry - Online First

The cyclodextrin-based metal-organic complex (CD-MONT-2) exhibits Pb (II)-rings-based luminescence and water-stable properties. In this paper, it was successfully utilized as a multifunctional material, applied as a fluorescent probe for Ag⁺ and an adsorbent for Congo red.

X-ray powder diffraction analysis (PXRD), fluorescence analysis (FL), UV-Vis spectroscopy (UV-Vis), Fourier infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and SEM X-ray energy dispersive spectrum (SEM-EDS) were employed to study and prove the mechanism Ag2O-involved.

The fluorescence intensity clearly decreases as Ag+ solution (1 mM in H2O) is added continuously. At a dose of 1.67 mM, the maximum fluorescence “turn-off” condition is reached, and at 432 nm, the fluorescence quenching percentage is almost 65%. ^{The adsorption capacity ofCD-MONT-2for Congo Red is 22.95 mg/g, with a removal rate of 71.98%.} Methyl orange follows with an adsorption capacity of 7.46 mg/g and a removal rate of 22.83%. The adsorption ability of rhodamine B by CD-MONT-2 is poor, the adsorption amount is 6.76 mg/g, and the removal rate is 19.75%.

The multifunctional CD-MONT-2 is utilized as an Ag⁺ probe through fluorescence quenching and naked-eye detection with good sensitivity and selectivity. The max fluorescence quenching percentage is 65% with the Ag⁺ concentration of 1.67 mM, and the LOD is calculated to be 0.3856 mM. As an adsorbent, we found that the Congo red (anionic dyes) could be efficiently adsorbed. The adsorption performance may come from the mutual attraction of positive and negative charges, and the interaction between CD-MONT-2-OH and Congo red-NH2. The kinetic results indicate that the adsorption process of CD-MONT-2 on CR is more in line with the pseudo second-order kinetic fitting model and is influenced by chemical reactions.

Particulate matter poses a significant risk to human health, particularly fine particulate matter, as it is difficult to eliminate and leads to severe health issues. Conversely, urban woody plants are experiencing ambient pollution directly and continuously adjusting to the dynamic contaminants, thereby improving the urban environment for their living circumstances. Thus, studies conducted at the level of individual leaves can offer important insights into the productivity of an ecosystem.

Leaf samples from three common woody plant species (Acer platanoides, Fraxinus excelsior, and Tilia tomentosa) in Budapest, Hungary, were collected throughout a vegetation phase. After ultrasonic wash-off, the chemical properties of dust deposits on the leaf surface were investigated.

Our results showed a higher concentration of wash-off fine particulate from F. excelsior than from A. platanoides and T. tomentosa, and the precipitation, maximum wind speed, and ambient particulate matter content did not demonstrate a significant impact on it. Thus, the fine particulate matter washed off from woody plant leaves involves a more dynamic and complex procedure. The analysis of chemical parameters demonstrated the interaction of particulate matter and the leaves; pH values varied, and the total electric conductivity was significantly higher than the accepted limits. The excessive concentration of sulphate and chloride in wash-off particulate matter indicated significant interference caused by human activities and secondary suspension.

Given that F. excelsior is more susceptible to having wash-off fine particulate matter, which can contribute to secondary suspension, the capability of A. platanoides and T. tomentosa to retain fine particulate may contribute to their effects in phytoremediation.

Combination therapy with polyphenol-rich natural spices has gained acceptance as a proactive approach for modulating human health owing to the COVID-19 pandemic. However, bioavailability is a significant hurdle in determining the actual potential of any herbal drug.

To improve the absorption of herbal drugs and to enhance their ability to affect the immune system, phospholipid complexes were developed for accommodating Curcumin with extracts of commonly found dietary spices like Piper longum, Piper nigrum, and Zingiber officinale aiming to have an effective immunomodulatory phytoformulation subduing the bioavailability limitation of Curcumin and delivery hurdle of phytoextracts for combination therapy. Since combination therapy with polyphenol-rich natural spices had surfaced as an effective mode of immunomodulation, phospholipid complexes were designed for encapsulating polyphenol-rich natural spices and Curcumin together and assessed for the most efficient phospholipid complexes with improved invitro therapeutic outcomes.

A quick and easy procedure for assessing the developed formulation using High-Performance Thin-Layer Chromatography (HPTLC) was developed. Antioxidant potential was measured by DPPH and Lipid peroxidation. Further immunomodulation was assessed in macrophages by NO inhibition assay and phagocytosis capacity.

The results showed that polyherbal phospholipid complexes exerted 2-fold enhanced antiradical properties (DPPH radical scavenging and inhibition of lipid peroxidation) as compared to Curcumin and significant inhibition of ROS in H2O2-induced human macrophages. Moreover, these polyherbal formulations were more effective in promoting macrophage proliferation, inhibiting LPS-induced NO production in macrophages, and enhancing phagocytosis in a dose-dependent manner.

Thus, phospholipid complexes offer a practical approach for developing nutraceuticals with augmented bioactivity of herbal components.

Liubao tea residues, often discarded as waste, may contain valuable bioactive compounds as polysaccharides. To characterize the physicochemical properties of polysaccharides extracted by 4 mol/L KOH (KTP) and investigate its effects on macrophage activation and immune response.

KTP was extracted using an alkaline method. Physicochemical characterization was performed using monosaccharide analysis, molecular weight assessment, FT-IR spectroscopy, XRD, and NMR spectroscopy. Immunomodulatory effects were evaluated through macrophage activation assays, focusing on NO production, cytokine release, and NF-κB pathway modulation.

Monosaccharide analysis identified KTP as a composite of arabinose, mannose, galactose, glucose, and xylose with distinct variations in abundance. Molecular weight analysis revealed KTP as a heterogeneous polysaccharide with fractions KTP-1 and KTP-2 of different molecular sizes. Structural characterization analysis showed specific functional groups, bond arrangements, and helical conformations, elucidating KTP’s intricate surface morphologies and semi-crystalline nature. Additionally, immunomodulatory studies demonstrated KTP’s activation of macrophage pathways via the NF-κB pathway, increasing nitric oxide (NO) and pro-inflammatory cytokine production dose-dependently.

This study reveals KTP's rich structural diversity and potent immunomodulatory activity, highlighting its potential as a natural immune booster and possible application in developing functional foods.

Crab hemolymph are rich in medicinally important secondary metabolites.

The objective of this study was to isolate, identify, and establish the crab hemolymph-derived secondary metabolites for the antifungal activity.

Several brachyuran crabs were investigated against 10 pathogenic strains. The disc diffusion method was used to investigate hemolymph extracts to identify potential brachyuran crabs showing antifungal activity. The moderately purified hemolymph was taken for RP-HPLC using a C-18 column. The obtained GC-MS-NIST formula/compound details were used to unveil the possible structures of obtained compounds. Individual compounds were confirmed by comparing the obtained structures with 1H NMR & 13C NMR results. The isolated Sparsomycin was subjected to a molecular docking Crystal Structure of Fungal RNA Kinase (PDB ID: 5U32).

Notably, most of the crab species in this study exhibited activity against various strains of fungi. The current findings demonstrated that the hemolymph of the crab Dromia dehaani exhibits broad-spectrum activity against pathogenic fungi. The D. dehaani showed the uppermost antimicrobial activity, and the most potent extracts obtained from the sponge crab, D. dehaani, displayed activity against several fungal organisms that included Candida albicans and Aspergillus niger. D. dehaani was selected for detailed investigations as the hemolymph of D. dehaani has the potential to be developed as an anti-microbial agent to treat infections.

The compounds isolated, identified, and established as antifungal agents could be the future drugs for restricting major fungal infections.

This study introduces basil seeds as a novel, low-cost, and environmentally friendly adsorbent for the removal of ciprofloxacin from aqueous solutions. The primary innovation of this work lies in the use of readily available basil seeds, which have not been widely explored for this purpose, to achieve high adsorption capacity and efficiency.

The adsorption process was systematically optimized by adjusting parameters such as time, temperature, pH, and ciprofloxacin concentration, with results showing maximum adsorption at 40 minutes, 70°C, and pH 7. Additionally, the study investigates the influence of interfering factors like competing ions and organic matter in water, providing a more realistic assessment of the material’s effectiveness.

The findings demonstrate that basil seeds offer a promising alternative to conventional adsorbents, presenting both environmental and economic advantages for water treatment applications.

This work significantly advances current knowledge by proposing a sustainable solution for pharmaceutical pollutant removal from contaminated water.

Wetlands are vital carbon sinks, with coastal salt marshes being particularly effective in carbon sequestration. Understanding how different vegetation types influence soil carbon storage and microbial composition can enhance our knowledge of these ecosystems’ roles in global carbon cycling.

This study investigates soil physicochemical properties, soil carbon storage, and microbial community composition and diversity at three depths (10, 30, and 60 cm) in five salt marsh plots from five coastal salt marshes: Bare flat (a non-vegetated marsh) and plots dominated by Imperata cylindrica, Solidago canadensis, Suaeda spp., and Phragmites australis. Carbon storage was evaluated by measuring soil organic carbon (SOC) content. At the same time, high-throughput sequencing was employed to analyze microbial communities, aiming to elucidate their relationships with soil carbon storage and wetland vegetation.

The average SOC contents in the five plots were in the order of S. canadensis (13.33 g·kg^–1) > Bare flat (11.45 g·kg^–1) > Suaeda spp. (8.10 g·kg^–1) > I. cylindrica (6.15 g·kg^–1) > P. australis (5.80 g·kg^–1). S. canadensis and Bare flat marshes had the highest carbon content, which is mainly attributed to the presence of the most abundant carbon-fixation microbes, Fulvivirgaceae (family) and Acidobacteria RB41 (genus), in the soil of these two plots. Both organic and dissolved organic carbon contents at 10 cm were higher than those at the other two depths for all five marshes.

The Bare flat exhibited strong carbon sequestration capability, second only to the invasive S. canadensis plot among the five plots surveyed. It also showed the highest microbial abundance and the greatest number of carbon-sequestration-related functional genes. The S. canadensis plot exhibited the lowest microbial community diversity and abundance despite having the highest carbon storage capacity. As an invasive species, S. canadensis should be removed to mitigate its ecological impact.

Heavy metals (HMs) such as Cr, Hg, Pb, etc., are major threats to human health due to their toxic and carcinogenic properties. So, the determination of HMs concentrations in waters is an actual and important task.

In this paper, the method includes a preliminary concentration of HMs and other analytes (Ag, Au, Ba, Be, Bi, Cr, Hg, In, Pb, Sn, and Zn) from water solutions on the graphene oxide and subsequent analysis of slurries of sorbent by electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP-OES) is developed for the first time.

The high efficiency of analytes sorption on graphene oxide made it possible to significantly increase the sensitivity of the analysis. The limits of detection of Ag, Au, Ba, Be, Bi, Cr, Hg, In, Pb, Sn, and Zn from 0.7 to 300 ng L^-1 are achieved for ETV-ICP-OES analysis. The use of electrothermal vaporization for sample introduction allows the analysis of sorbent suspensions and avoids the desorption stage, reduces sample dilution, increases the preconcentration factor, and improves limits of detection (LODs) of analytes by 2-33 times compared to routine inductively coupled plasma optical emission spectrometry analysis (ICP-OES) with sorption preconcentration.

For Ba, Be, Bi, Cr, In, Pb, Sn, and Zn ETV-ICP-OES provides LODs from 2 to 33 times lower compared to conventional ICP-OES analysis with sorption preconcentration due to higher preconcentration factor and transport efficiency of introducing of the analytes concentrates into the ICP. The developed method was applied to the analysis of real tap and mineral water samples. The results of analysis by ETV-ICP-OES with preconcentration of trace elements and ICP-OES were in good agreement. As a result of lower LODs of analytes, ETV-ICP-OES analysis provides the determination of concentrations of Ba, Bi, Sn, and Pb in tap and mineral water samples.

L-cysteine (L-Cys) and homocysteine (Hcy) are the most representative of biothiol, which exist widely in organisms. L-Cys is one of the essential amino acids, which can be absorbed from protein-rich food and plays a considerable role in various physiological processes. Hcy is a vital intermediate in normal mammalian metabolism of methionine but does not occur in the diet. Therefore, it is significant to exploit a rapid and sensitive strategy to measure L-Cys and Hcy.

Herein, we designed an “on-on” fluorescent platform for detecting L-Cys and Hcy with gold nanoclusters (AuNCs) as probes. During the sensing process, cadmium ions (Cd²⁺) acted as mediating substances to connected AuNCs and L-Cys (or Hcy), and triggered aggregation-induced emission (AIE) effect.

The linear ranges achieved with fluorimetry of L-Cys and Hcy were 0.1-10.0 μM and 0.1-20.0 μM, respectively. Moreover, this fluorescent probe was successfully used to determine the L-Cys concentration in actual samples, and showed excellent recovery.

Furthermore, the mechanism for sensing L-Cys and Hcy has been exhaustively investigated.