Cyclodextrin-based ternary supramolecular deep eutectic solvents for efficient extraction and analysis of trace quinolones and sulfonamides in wastewater by adjusting pH.

BACKGROUND: Antibiotics residues can accelerate the growth of drug-resistant bacteria and harm the ecological environment. Under the effect of enrichment and biomagnification, the emergence of drug-resistant pathogenic bacteria may eventually lead to humans being ineffective to drugs in the face of bacterial or fungal disease infections in the future. It is urgent to develop an efficient separation medium and analytical method for simultaneous extraction and determination of antibiotics in the water environment. RESULTS: This work doped 2,6-Di-O-methyl-ß-cyclodextrin, randomly methyl-ß-cyclodextrin, 2-hydroxypropyl-ß-cyclodextrin with thymol:fatty acid respectively to construct non-covalent interaction-dominated pH-responsive ternary supramolecular deep eutectic solvents (SUPRADESs), which can undergo a hydrophilic/hydrophobic transition with aqueous phase to achieve an efficient microextraction. Semi-empirical method illustrated that SUPRADESs have a wide range of hydrogen bond receptor sites. We developed a SUPRADES-based analytical method combined with liquid chromatography-triple quadrupole mass spectrometry for the extraction and determination of trace quinolones and sulfonamides in wastewater. The overall limits of detection of the method were 0.0021-0.0334 ng mL-1 and the limits of quantification were 0.0073-0.1114 ng mL-1. The linearity maintained good in the spiked level of 0.01-100 ng mL-1 (R2 > 0.99). The overall enrichment factors of the method were 157-201 with lower standard deviations (≤8.7). SIGNIFICANCE: The method gave an extraction recovery of 70.1-115.3 % for 28 antibiotics in livestock farming wastewater samples from Zhejiang, China, at trace levels (minimum 0.5 ng mL-1). The results demonstrated that inducing the phase transition between SUPRADES and aqueous phase by adjusting pH for extraction is a novel and efficient pretreatment strategy. To our knowledge, this is the first application of cyclodextrin-based ternary SUPRADESs with pH-responsive reversible hydrophobicity-hydrophilicity transition behavior in wastewater analysis.

Development of a NiFe2O4 covalent organic framework based magnetic solid-phase extraction approach for specific capture of quinolones in animal innards prior to UHPLC-Q-Orbitrap HRMS detection.

This study aimed to present a selective and effective method for analyzing quinolones (QNs) in food matrix. Herein, a NiFe2O4-based magnetic sodium disulfonate covalent organic framework (NiFe2O4/COF) was prepared using a simple solvent-free grinding method, and was adopted as a selective adsorbent for magnetic solid phase extraction of QNs. Coupled with UHPLC-Q-Orbitrap HRMS, an efficient method for simultaneous detection of 18 kinds of QNs was established. The method exhibited good linearity (0.01-100 ng g-1), high sensitivity (LODs ranging from 0.0011 to 0.0652 ng g-1) and precision (RSDs below 9.5%). Successful extraction of QNs from liver and kidney samples was achieved with satisfactory recoveries ranging from 82.2% to 108.4%. The abundant sulfonate functional groups on NiFe2O4/COF facilitated strong affinity to QNs through electrostatic and hydrogen bonding interactions. The proposed method provides a new idea for the extraction of contaminants with target selectivity.

New Analogues of Amides and Quinolinones Produced by Streptomyces sp. YIM S01983.

Streptomide (1), a new amide analogue, streptomynone (2), a new quinolinone, and ten known compounds including three aliphatic acids (3-5), two amides (6-7), four cyclic dipeptides (8-11), and an adenosine (12) were isolated from the fermentation broth of Streptomyces sp. YIM S01983 isolated from a sediment sample collected in Bendong Village, Huadong Town, Chuxiong, China. Their structures were determined by analysis of the 1D/2D-NMR and HR-ESI-MS spectra. Compound 12 presented weak antimicrobial activities against Candida albicans and Aligenes faecalis (MIC=64 µg/mL). Compounds 7 and 12 showed weak cytotoxic activity against MHCC97H.

Penicilloneines A and B, Quinolone-Citrinin Hybrids from a Starfish-Derived Penicillium sp.

Penicilloneines A (1) and B (2) are the first reported quinolone-citrinin hybrids. They were isolated from the starfish-derived fungus Penicillium sp. GGF16-1-2, and their structures were elucidated using spectroscopic, chemical, computational, and single-crystal X-ray diffraction methods. Penicilloneines A (1) and B (2) share a common 4-hydroxy-1-methyl-2(1H)-quinolone unit; however, they differ in terms of citrinin moieties, and these two units are linked via a methylene bridge. Penicilloneines A (1) and B (2) exhibited antifungal activities against Colletotrichum gloeosporioides, with lethal concentration 50 values of 0.02 and 1.51 µg/mL, respectively. A mechanistic study revealed that 1 could inhibit cell growth and promote cell vacuolization and consequent disruption of the fungal cell walls via upregulating nutrient-related hydrolase genes, including putative hydrolase, acetylcholinesterase, glycosyl hydrolase, leucine aminopeptidase, lipase, and beta-galactosidase, and downregulating their synthase genes 3-carboxymuconate cyclase, pyruvate decarboxylase, phosphoketolase, and oxalate decarboxylase.

Oxepine-containing pyrazinopyrimidine alkaloids and quinolinone derivatives produced by Aspergillus versicolor AS-212, a deep-sea-derived endozoic fungus.

Four new oxepine-containing pyrazinopyrimidine alkaloids, versicoxepines A - D (1-4), two quinolinone alkaloid analogs including 3-hydroxy-6-methoxy-4-phenylquinolin-2(1H)-one (5) and 3-methoxy-6-hydroxy-4-phenylquinolin-2(1H)-one (6) which were new naturally occurring compounds, together with two known compounds (7 and 8) were isolated from Aspergillus versicolor AS-212, an endozoic fungus isolated from the deep-sea coral Hemicorallium cf. imperiale, which was collected from the Magellan Seamounts in the Western Pacific Ocean. Their structures were determined by extensive analysis of the spectroscopic and X-ray crystallographic data as well as by chiral HPLC analysis, ECD calculation, and DP4+ probability prediction. Structurally, versicoxepines B and C (2 and 3) represent the first example of a new oxepine-containing pyrazinopyrimidine alkaloid whose cyclic dipeptide moiety is composed of the same type of amino acid (Val or Ile). Compound 5 displayed antibacterial activity against aquatic pathogens, Vibrio harveyi and V. alginolyticus, with MICs of 8 µg/mL.

Antimicrobial and Cytotoxic Angucyclic Quinones from Actinomadura miaoliensis.

Eight new angucyclic quinones, miaosporones A to H (1-8), along with the previously described metabolites 8-hydroxy-3-methylbenz[a]anthraquinone (9), tetrangulol (10), 5,6-dihydro-1,8-dihydroxy-3-methybenz[a]anthracene-7,12-quinone (11), and SF2315A (12), were isolated from the terrestrial actinomycete Actinomadura miaoliensis TBRC 5172 obtained from sediment collected from the Huai Yang reservoir, Prachuap Khiri Khan Province, Thailand. The relative and absolute configurations of the new compounds were determined from analysis of NMR spectroscopic and X-ray crystallographic data. Miaosporone A exhibited antimalarial activity against Plasmodium falciparum K1 and antibacterial activity against Mycobacterium tuberculosis with respective IC50 values of 2.5 and 2.4 µM and displayed cytotoxic activities against both cancerous (MCF-7 and NCI-H187) and nonmalignant (Vero) cells.

Jorunnamycin A Suppresses Stem-Like Phenotypes and Sensitizes Cisplatin-Induced Apoptosis in Cancer Stem-Like Cell-Enriched Spheroids of Human Lung Cancer Cells.

It has been recognized that cancer stem-like cells (CSCs) in tumor tissue crucially contribute to therapeutic failure, resulting in a high mortality rate in lung cancer patients. Due to their stem-like features of self-renewal and tumor formation, CSCs can lead to drug resistance and tumor recurrence. Herein, the suppressive effect of jorunnamycin A, a bistetrahydroisoquinolinequinone isolated from Thai blue sponge Xestospongia sp., on cancer spheroid initiation and self-renewal in the CSCs of human lung cancer cells is revealed. The depletion of stemness transcription factors, including Nanog, Oct-4, and Sox2 in the lung CSC-enriched population treated with jorunnamycin A (0.5 µM), resulted from the activation of GSK-3ß and the consequent downregulation of ß-catenin. Interestingly, pretreatment with jorunnamycin A at 0.5 µM for 24 h considerably sensitized lung CSCs to cisplatin-induced apoptosis, as evidenced by upregulated p53 and decreased Bcl-2 in jorunnamycin A-pretreated CSC-enriched spheroids. Moreover, the combination treatment of jorunnamycin A (0.5 µM) and cisplatin (25 µM) also diminished CD133-overexpresssing cells presented in CSC-enriched spheroids. Thus, evidence on the regulatory functions of jorunnamycin A may facilitate the development of this marine-derived compound as a novel chemotherapy agent that targets CSCs in lung cancer treatment.

New limonoids and quinolone alkaloids with cytotoxic and anti-platelet aggregation activities from Evodia rutaecarpa (Juss.) Benth.

One new limonoid, named 19-hydroxy methyl isoobacunoate diosphenol (1); one new degraded limonoid, named 9α-methoxyl dictamdiol (9); two new quinolone alkaloids, 1-methyl-3-[(7E,9E,12Z)-7,9,12-pentadecadienyl]-4(1H)-quinolone (11) and 1-methyl-3-[(7E,9E,11E)-7,9,11-pentadecadienyl]-4(1H)-quinolone (12), along with eight known compounds, evodol (2), 7ß-acetoxy-5-epilimonin (3), rutaevine (4), 6ß-acetoxy-5-epilimonin (5), limonin (6), obacunone (7), clauemargine L (8), hiiranlactone E (10) were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth.. Structures of the four new compounds were elucidated on the basis of extensive spectroscopic techniques, including 1D and 2D NMR techniques. Compounds 3, 5, 9, 11 and 12 showed obviously cytotoxic activity against six human tumor lines, while compounds 11, 12 displayed anti-platelet aggregation induced by ADP at 50 µM and 100 µM.

Enantiomeric resolution of quinolones on crown ether CSP: Thermodynamics, chiral discrimination mechanism and application in biological samples.

The enantiomers of quinolone racemates were resolved using chiral crown ether within 8 min. Thermodynamics data and modeling results were used to determine chiral recognition mechanism. The column used was (+)-Crownpack column (250 mm × 4.6 mm, 5 µm) with three mobile phases I: ACN:Water (80:20) + 10 mM H2SO4 and 10 mM CH3COONH4, II: ACN:Water (80:20) + 20 mM perchloric acid and III: EtOH:Water (80:20) + 20 mM perchloric acid. The flow rate of the mobile phases was 1.0 mL/min with UV detection at different wavelengths. The ranges of retention (k), separation (α), and resolution (Rs) factors were 1.00-5.40, 1.37-2.00 and 1.50-3.30. The tailing factor was 1.o for all peaks with 900-2325 as the number of theoretical plates were 8.0-10.0 and 32.4-22.1 µg. The difference in enthalpy, entropy and free energy varied in the range of -0.350 to -0.024, 18.74 × 10-4 to 3.94 × 10-4 and -0.918 to -0.143, respectively. The thermodynamic and docking results showed chiral discrimination due to physical forces of amnio group cations penetration into the chiral cavity of the chiral selector following hydrogen bindings. The binding energy of S-enantiomers was higher than R-enantiomers; confirming stronger binding of S-enantiomers with CSP than R-enantiomers. The described chiral-HPLC method was used for the analysis of the quinolone enantiomers in urine samples and the results were quite satisfactory. Therefore, the reported method may be used for the enantiomeric separation of quinolone enantiomers in urine samples.

Pesimquinolones I-S, eleven new quinolone alkaloids produced by Penicillium simplicissimum and their inhibitory activity on NO production.

Eleven undescribed quinolone alkaloids, pesimquinolones I-S (1-4 and 6-12), as well as eleven known congeners (5 and 13-22), were isolated from the solid culture broth of the fungus Penicillium simplicissimum. Their chemical structures with absolute configurations were established by a combination of NMR spectroscopy, single-crystal X-ray crystallography, and modified Mosher's methods. Pesimquinolones I-K (1-3) represent the first examples of natural occurring quinolone alkaloids that possess a 6/6/6/6 tetracyclic ring system. The anti-inflammatory activities of selected compounds on LPS-induced nitric oxide (NO) production in adherent cells were evaluated. Compounds 1 and 2 showed suppressive effects on the production of NO, with IC50 values of 10.13 and 8.10 µM, respectively.

Pyrroloquinolone A, a new alkaloid and other phytochemicals from Atractylis cancellata L. with antioxidant and anticholinesterase activities.

A new alkaloid pyrroloquinolone A (1), along with fifteen known compounds 2-16 were isolated from the petroleum ether, EtOAc and n-BuOH extracts of the whole plant Atractylis cancellata L. Their structures were elucidated on the basis of extensive spectroscopic analysis including 1D- and 2D-NMR and HR-ESI-MS techniques. This is the first report of alkaloids in the genus Atractylis. Some of the isolated compounds and extracts were evaluated for their antioxidant potential (scavenging activity of DPPH and ABTS radicals, and reducing Fe+3 and Cu+2 power assays) and acetylcholinesterase and butyrylcholinesterase inhibitory activities. Compounds 8 and 11 showed good antioxidant capacity compared to ascorbic acid, BHA, and BHT used as standards, whereas compounds 1 and 2 exhibited good anticholinesterase activities compared to galantamine used as standard.

Viridicatol Isolated from Deep-Sea Penicillium Griseofulvum Alleviates Anaphylaxis and Repairs the Intestinal Barrier in Mice by Suppressing Mast Cell Activation.

Viridicatol is a quinoline alkaloid isolated from the deep-sea-derived fungus Penicillium griseofulvum. The structure of viridicatol was unambiguously established by X-ray diffraction analysis. In this study, a mouse model of ovalbumin-induced food allergy and the rat basophil leukemia (RBL)-2H3 cell model were established to explore the anti-allergic properties of viridicatol. On the basis of the mouse model, we found viridicatol to alleviate the allergy symptoms; decrease the levels of specific immunoglobulin E, mast cell protease-1, histamine, and tumor necrosis factor-α; and promote the production of interleukin-10 in the serum. The treatment of viridicatol also downregulated the population of B cells and mast cells (MCs), as well as upregulated the population of regulatory T cells in the spleen. Moreover, viridicatol alleviated intestinal villi injury and inhibited the degranulation of intestinal MCs to promote intestinal barrier repair in mice. Furthermore, the accumulation of Ca2+ in RBL-2H3 cells was significantly suppressed by viridicatol, which could block the activation of MCs. Taken together, these data indicated that deep-sea viridicatol may represent a novel therapeutic for allergic diseases.

HPLC enantio-separation and chiral recognition mechanism of quinolones on vancomycin CSP.

A new HPLC method was developed for the enantio-separation and chiral recognition mechanism of quinolones (lomefloxacine, ofloxacine, primaquine and quinacrine) on Vancomycin CSP. The column used was Chirabiotic V column (150 × 4.6 mm, 5.0 µm) with two mobile phases i.e. (I) MeOH:ACN:H2O:TEA (50:30:20:0.1%) and (II) MeOH:ACN: H2O:TEA (70:10:20:0.1%) at 1.0 mL/minute flow rate with various UV detection. The values of retention, separation and resolution factors in a solvent system I were ranged from 2.20 to 5.05, 1.70 to 1.96 and 1.75 to 2.20 while these values were 1.93 to 6.85, 1.62 & 2.01 and 2.30 & 2.40 in solvent system II. The limits of detection and quantification were ranged from 8.0 to 10.5 µg and 24.4 to 33.5 µg. The resolution was controlled mainly by π-π interactions along with other forces like hydrogen bonding, van der Waal's forces, steric effects, etc. The determination of the chiral recognition mechanism may be beneficial to separate other racemates successfully. The method is fast precise and efficient and may be utilized to analyze enantiomers of the reported quinolones.

Alkaloids from the nearly ripe fruits of Evodia rutaecarpa and their bioactivities.

Two novel quinolone alkaloids (1 and 2) and two novel indole alkaloids (5 and 8), together with eleven known analogues, were isolated from the nearly ripe fruits of Evodia rutaecarpa. Their structures were determined by extensive spectroscopic data, including NMR, HRESIMS, and ECD. Additionally, the anti-tumor, hypoglycemic, and anti-bacterial activities of the isolated alkaloids were evaluated in vitro. Compound 5 as a new alkaloid displayed moderate inhibitory effect against four human cancer cell lines (MCF-7 IC50 = 30.7 µM, Hepg-2 IC50 = 65.2 µM, A549 IC50 = 39.1 µM, and SHSY-5Y IC50 = 24.7 µM), α-glucosidase (IC50 = 23.9 µM) and PTP1B (IC50 = 75.8 µM). Compound 11 showed better inhibitory effect against PTP1B (IC50 = 16.2 µM) compared with that of the positive control. Compounds 5, 13, and 14 showed moderate inhibitory effects against Bacillus cereus with MIC values of 50, 25, and 10 µM, respectively.

Two new quinolone alkaloids from the nearly ripe fruits of Tetradium ruticarpum.

Tetradium ruticarpum (Juss.) Benth. belong to the family of Rutaceae. The complete and nearly ripe fruits of T. ruticarpum is used as traditional Chinese medicine and phytochemical investigations have been conducted on extracts of the seeds of T. ruticarpum to provide scientific validation of its properties. In this study, we successfully isolated two new quinolone alkaloids (1-2) from the MeOH extractive of nearly ripe fruits of T. ruticarpum. The structure elucidation of these compounds was determined by one- and two-dimensional nuclear magnetic resonance, ultraviolet and electrospray ionisation time-of-flight mass spectrometry. This finding expands the understanding of the natural constituents of the Rutaceae, in particular, the Tetradium genera.

Prenylated quinolinone alkaloids and prenylated isoindolinone alkaloids from the fungus Aspergillus nidulans.

Two undescribed prenylated quinolinone alkaloids, aspoquinolones E and F, and three undescribed prenylated isoindolinone alkaloids aspernidines F-H, were isolated from the fungus Aspergillus nidulans. Their structures and configurations were elucidated based on spectroscopic analyses and ECD spectra. Aspoquinolones E and F possess a C10 moiety with an unusual 2,2,4-trimethyl-3oxa-bicyclo[3.1.0]hexane unit, and aspernidines F-H own a C15 side chain. These compounds were evaluated for cytotoxic activities against five human cancer cell lines, compounds 1 and 5 exhibited strong inhibitory activities against A-549 and SW-480 cells with IC50 values of 3.50 and 4.77 µM, respectively.

Polyketides and a Dihydroquinolone Alkaloid from a Marine-Derived Strain of the Fungus Metarhizium marquandii.

Three new natural products (1-3), including two butenolide derivatives (1 and 2) and one dihydroquinolone derivative (3), together with nine known natural products were isolated from a marine-derived strain of the fungus Metarhizium marquandii. The structures of the new compounds were unambiguously deduced by spectroscopic means including HRESIMS and 1D/2D NMR spectroscopy, ECD, VCD, OR measurements, and calculations. The absolute configuration of marqualide (1) was determined by a combination of modified Mosher's method with TDDFT-ECD calculations at different levels, which revealed the importance of intramolecular hydrogen bonding in determining the ECD features. The (3R,4R) absolute configuration of aflaquinolone I (3), determined by OR, ECD, and VCD calculations, was found to be opposite of the (3S,4S) absolute configuration of the related aflaquinolones A-G, suggesting that the fungus M. marquandii produces aflaquinolone I with a different configuration (chiral switching). The absolute configuration of the known natural product terrestric acid hydrate (4) was likewise determined for the first time in this study. TDDFT-ECD calculations allowed determination of the absolute configuration of its chirality center remote from the stereogenic unsaturated γ-lactone chromophore. ECD calculations aided by solvent models revealed the importance of intramolecular hydrogen bond networks in stabilizing conformers and determining relationships between ECD transitions and absolute configurations.

Graphene oxide composites for magnetic solid-phase extraction of twelve quinolones in water samples followed by MALDI-TOF MS.

Antibiotic compounds in natural waters are normally present at low concentrations. In this paper, an easy and highly sensitive screening method using graphene oxide-functionalized magnetic composites (GO@NH2@Fe3O4) combined with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was established for twelve quinolone antibiotics. GO@NH2@Fe3O4 composites were utilized as adsorbents for magnetic solid-phase extraction. This method combines the advantages of magnetic solid-phase extraction and MALDI-TOF MS, which allows for fast detection of quinolones at low concentrations. To improve absorption efficiency, the following parameters were individually optimized: sample acidity, extraction time, amount of adsorbent used, eluent used, and desorption time. Under the optimum conditions, the established method gave a low detection limit of 0.010 mg/L and allowed the high-throughput screening of twelve quinolone antibiotics (enoxacin, norfloxacin, ciprofloxacin, pefloxacin, fleroxacin, gatifloxacin, enrofloxacin, levofloxacin, sparfloxacin, danofloxacin, difloxacin, and lomefloxacin). The proposed method, having an easily prepared sorbent with a high affinity for quinolones and a convenient, high-throughput detection step, has been shown to have merit for the detection of antibiotics in water samples. Graphical abstract Schematic illustration of the (A) preparation of GO@NH2@Fe3O4 and (B) operating procedure for the MSPE and MALDI-TOF MS detection of QNs.

Jorunnamycin A from Xestospongia sp. Suppresses Epithelial to Mesenchymal Transition and Sensitizes Anoikis in Human Lung Cancer Cells.

Metastasis is a key driving force behind the high mortality rate associated with lung cancer. Herein, we report the first study revealing the antimetastasis activity of jorunnamycin A, a bistetrahydroisoquinolinequinone isolated from a Thai blue sponge Xestospongia sp. evidenced by its inhibition of epithelial to mesenchymal transition (EMT), sensitization of anoikis, and suppression of anchorage-independent survival in human lung cancer cells. Treatment with jorunnamycin A (0.05-0.5 µM) altered the expression of p53 and Bcl-2 family proteins, particularly causing the down-regulation of antiapoptosis Bcl-2 and Mcl-1 proteins. Under detachment conditions for 12 h, jorunnamycin A-treated cells exhibited diminution of pro-survival proteins p-Akt and p-Erk as well as the survival-promoting factor caveolin-1. Corresponding with the inhibition on the Akt and Erk pathway as well as activation of p53, there was an increase in the epithelial marker E-cadherin and a remarkable decrease of EMT markers and associated proteins including vimentin, snail, and claudin-1. As the loss of anchorage dependence is an important barrier to metastasis, the observed inhibitory effects of jorunnamycin A on the coordinating networks of EMT and anchorage-independent growth emphasize the potential development of jorunnamycin A as an effective agent against lung cancer metastasis.

Glycopentanolones A-D, four new geranylated quinolone alkaloids from Glycosmis pentaphylla.

The ethanolic extract obtained from the stems of Glycosmis pentaphylla was found to suppress antigen-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells. Four new geranylated 2-quinolone alkaloids, named glycopentanolones A-D (1-4), and 12 known metabolites (5-16) were isolated from the ethanolic extract from the stems of G. pentaphylla using bioassay-guided fractionation. Their structures were elucidated by a combination of 1D and 2D NMR, and HRESI-MS. The inhibitory effects of the isolated constituents on ß-hexosaminidase release from RBL-2H3 cells were examined, and compounds 1, 5, 8 and 11 exhibited potent inhibitory activity with IC50 values between 0.05 and 4.28 µM.