Psathrosterols C-E, highly conjugated ergosterol derivatives from Psathyrella rogueiana with anti-inflammatory and immunosuppressive activity.

Three new ergosterols featuring with a highly conjugated ring system, psathrosterols C-E (1-3), have been isolated from the fungus Psathyrella rogueiana. The structures with the absolute configurations were elucidated by means of spectroscopic methods and single crystal X-ray diffraction. Compounds 1-3 exhibit inhibitory activity against NO production with IC50 values ranging from 8.4 to 21.8 µM. Compound 1 inhibits the LPS-induced proliferation of B lymphocyte cells with an IC50 value of 12.3 µM.

A novel low-background nitroreductase fluorescent probe for real-time fluorescence imaging and surgical guidance of thyroid cancer resection.

Thyroid cancer always appears insidiously with few noticeable clinical symptoms. Due to its limitations, conventional ultrasound imaging can lead to missed or misdiagnosed cases. Surgery is still the primary treatment method of thyroid cancer, but removal of surrounding healthy tissues to minimize recurrence leads to overtreatment and added patient suffering. To address this challenge, herein, a nitroreductase (NTR) fluorescent probe, Ox-NTR, has been developed for detecting thyroid cancer and tracking the surgical removal of thyroid tumors by fluorescence imaging. The conjugated structure of oxazine 1 was disrupted, significantly reducing the issue of high background signals, thus effectively achieving low background fluorescence. Under hypoxic conditions, the nitro group of Ox-NTR can be reduced to an amine and subsequently decomposed into oxazine 1, emitting intense red fluorescence. Ox-NTR has a low detection limit of 0.09 µg/mL for NTR with excellent photostability and selectivity. Cellular studies show that Ox-NTR can effectively detect NTR levels in hypoxic thyroid cancer cells. Moreover, the ability of Ox-NTR of rapid response to thyroid cancer in vivo is confirmed by fluorescence imaging in mice, distinguishing tumors from normal tissues due to its superior low background fluorescence. Utilizing this fluorescence imaging method during surgical resection can guide the removal of tumors, preventing both missed tumor tissues and accidental removal of healthy tissue. In summary, the novel Ox-NTR offers precise detection capabilities that provide significant advantages over traditional imaging methods for thyroid cancer diagnosis and treatment, making it a valuable tool to guide tumor removal in surgical procedures.

A novel NIR fluorescent probe for enhanced ß-galactosidase detection and tumor imaging in ovarian cancer models.

The advancement of biological imaging techniques critically depends on the development of novel near-infrared (NIR) fluorescent probes. In this study, we introduce a designed NIR fluorescent probe, NRO-ßgal, which exhibits a unique off-on response mechanism to ß-galactosidase (ß-gal). Emitting a fluorescence peak at a wavelength of 670 nm, NRO-ßgal showcases a significant Stokes shift of 85 nm, which is indicative of its efficient energy transfer and minimized background interference. The probe achieves a remarkably low in vitro detection limit of 0.2 U/L and demonstrates a rapid response within 10 min, thereby underscoring its exceptional sensitivity, selectivity, and operational swiftness. Such superior analytical performance broadens the horizon for its application in intricate biological imaging studies. To validate the practical utility of NRO-ßgal in bio-imaging, we employed ovarian cancer cell and mouse models, where the probe's efficacy in accurately delineating tumor cells was examined. The results affirm NRO-ßgal's capability to provide sharp, high-contrast images of tumor regions, thereby significantly enhancing the precision of surgical tumor resection. Furthermore, the probe's potential for real-time monitoring of enzymatic activity in living tissues underscores its utility as a powerful tool for diagnostics in oncology and beyond.

A highly sensitive ratiometric fluorescent probe based on fluorescein coumarin for detecting hydrazine in actual water and biological samples.

Hydrazine (N2 H4 ) is a highly toxic and harmful chemical reagent. Fluorescent probes are simple and efficient tools for sensitive monitoring of N2 H4 enrichment in the environment, humans, animals, and plants. In this work, a ratiometric fluorescent probe (FP-1) containing coumarin was used for hydrazine detection. The proposed FP-1 probe had a linear detection range of 0-250 µM and a limit of detection (LOD) of 0.059 µM (1.89 ppb). A large red Stokes shift was observed in fluorescence and UV-vis absorption spectra due to the hydrolysis of ester bonds between FP-1 and hydrazine. The hydrazine detection mechanism of FP-1 was also investigated using density functional theory (DFT) calculations. Finally, FP-1 could sensitively and selectively monitor hydrazine in actual water samples and BEAS-2B cells. Therefore, it has great application potential in environmental monitoring and disease diagnosis.

A mitochondria-targeted rhodol fluorescent probe for imaging of hydrogen peroxide in living cells.

Hydrogen peroxide (H2O2) is a main member of reactive oxygen species (ROS) in cells that has a significant impact on various physiological and pathological processes of organisms. Here, we designed and synthesized a new type of fluorescent probe Rhodol-OAc for the specific detection of H2O2. The probe had good water solubility, high selectivity and sensitivity to H2O2, low cytotoxicity, excellent mitochondrial targeting ability, etc. It was successfully applied in the imaging of exogenous and endogenous H2O2 in living cells. In addition, theoretical calculations were carried out to clarify the luminescence mechanism of the probe. More importantly, we successfully applied the probe to indirectly detect xanthine and glucose, the metabolism of which generates H2O2, and achieved satisfactory results.

A novel ratiometric fluorescent probe for selective detection and imaging of H2S.

In this work, a novel phenoxazine-based fluorescent probe BPO-N3 was developed to detect H2S. The results showed that the probe had high selectivity and sensitivity toward H2S, and its detection mechanism was based the ratio between green and red fluorescence signals; its detection limit was as low as 30 nM. The fluorescent imaging experiments further showed that the probe BPO-N3 could successfully detect endogenous and exogenous H2S in living cells. This probe can be used as a powerful tool for in-depth study of H2S function in various physiological processes.

1,3,5-Triazine-azole Hybrids and their Anticancer Activity.

1,3,5-Triazine and azole can interact with various therapeutic targets, and their derivatives possess promising in vitro and in vivo anticancer activity. Hybrid molecules have the potential to enhance efficiency, overcome drug resistance and reduce side effects, and many hybrid molecules are under different phases of clinical trials, so hybridization of 1,3,5-triazine with azole may provide valuable therapeutic intervention for the treatment of cancer. Substantial efforts have been made to develop azole-containing 1,3,5-triazine hybrids as novel anticancer agents, and some of them exhibited excellent activity. This review emphasizes azole-containing 1,3,5-triazine hybrids with potential anticancer activity, and the structure-activity relationships as well as the mechanisms of action are also discussed to provide comprehensive and target-oriented information for the development of this kind of anticancer drugs.

The Anti-Breast Cancer Potential of Bis-Isatin Scaffolds.

AIM: To develop novel anti-breast cancer agents and discuss the structure-activity relationship of bis-isatin scaffolds. BACKGROUND: Breast cancer is the most common invasive cancer and the second leading cause of cancer death in women after lung cancer. Bis-isatin scaffolds possess potential anti-breast cancer activity, and some of them such as Indirubin could induce cancer cells apoptosis via multiply mechanisms. OBJECTIVE: The primary objective of this study was to evaluate the potential of bis-isatin scaffolds with alkyl/ether linkers between the two isatin moieties against different human breast cancer cell lines including MCF-7, AU565, MDA-MB-231, MDA-MB-435 and MDA-MB-468 cells. METHODS: The synthesized bis-isatin scaffolds with alkyl/ether linker between the two isatin moieties were evaluated for their in vitro activity against MCF-7, AU565, MDA-MB-231, MDA-MB-435, and MDA-MB-468 human breast cancer cell lines by MTT assay. RESULTS: All the synthesized compounds (IC50: 38.3-197.6 µM) possess considerable activity against MCF-7, AU565, MDA-MB-231, MDA-MB-435, and MDA-MB-468 human breast cancer cell lines, and the most potent compound 4e (IC50: 38.3-63.5 µM) was no inferior to Cisplatin (IC50: 20.1-38.6 µM) against the five tested human breast cancer cell lines. CONCLUSION: All the synthesized bis-isatin scaffolds were active against a panel of breast cancer cell lines, highlighting the significance of exploring the bis-isatin scaffolds to fight against breast cancers. The enriched structure-activity relationship may set up the direction for the rational design and development of novel bis-isatin scaffolds with higher efficiency.

Design of a Nile red-based NIR fluorescent probe for the detection of hydrogen peroxide in living cells.

In this article, a novel fluorescent probe (NRBE) for detecting H2O2 was developed using benzyl boronic ester as the H2O2-recognized group and Nile red as the matrix. The probe has several advantages, such as good selectivity, high sensitivity (LOD = 75 nM), good water solubility and emission in the near-infrared region (ex/em:585/670 nm). With the NRBE probe, the endogenous H2O2 in human hepatocellular carcinoma cells BEL-7402, was detected, and the H2O2 generated during the ischemia-reperfusion of the cells was imaged. These results show that NRBE can be applied for real-time detection of H2O2 in biological systems.

Two new illudane sesquiterpenoids and one new menthane monoterpene from cultures of Craterellus cornucopioides.

Two new illudane sesquiterpenoids, craterellins D and E (1 and 2), and one new menthane monoterpene, 4-hydroxy-4-isopropenyl-cyclohexanemethanol acetate (3), were isolated from cultures of Craterellus cornucopioides. Structures of 1-3 were elucidated on the basis of extensive spectroscopic analysis. Their cytotoxic activities on five tumor cell lines were evaluated.

A highly selective and sensitive rhodamine-derived fluorescent probe for detection of Cu2.

A novel water-soluble and reversible fluorescent probe was designed and synthesized based on a rhodamine B derivative. It was used for detection of Cu2+ in drinking water and in living cells with high sensitivity and excellent selectivity. The tested concentration range and the limit of detection (LOD) of the probe were 0-15.00µmolL-1 and 0.085µmolL-1, respectively. In addition, the mode of binding and mechanism of interaction between the probe and Cu2+ were analyzed by density functional theory (DFT) calculations.

Synthesis and application of thiol-functionalized magnetic nanoparticles for studying interactions of epirubicin hydrochloride with bovine serum albumin by fluorescence spectrometry.

A novel method was developed for studying the interaction between epirubicin hydrochloride (EPI) and bovine serum albumin (BSA) by fluorescence spectrometry. Fe3 O4 magnetic nanoparticles (MNPs) synthesized and functionalized with thiol group were employed for the immobilization and separation of target BSA in reaction solutions. The concentrations of the non-immobilized BSA and unbound EPI were obtained separately by fluorescence spectrometry. The binding constants (Ka ) and number of binding sites (n) of EPI with BSA were calculated. In this study, the Ka value was 5.05 × 105  L mol-1 , suggesting a strong binding of EPI to BSA, and the n value was 1.15. The effects of common metal ions on Ka of EPI with BSA were also investigated, and the results showed there was clearly bindings between the metal ions and BSA. The precise binding sites of EPI on BSA were determined as being in site I from the competitive displacement experiments. Copyright © 2016 John Wiley & Sons, Ltd.

A novel fluorescent probe for Cr(3+) based on rhodamine-crown ether conjugate and its application to drinking water examination and bioimaging.

A trivalent chromium (Cr(3+)) fluorescence probe (RhC) was designed and synthesized via Schiff base reaction based on rhodamine-crown ether conjugate. This probe displayed a favorable selectivity for Cr(3+) over a range of other common metal ions in DMF/H2O (3:7, v/v; PBS buffer 50 mmol L(-1); pH=6.8) solution, leading to prominent fluorescence "OFF-ON" switching of the rhodamine fluorophore. The limit of detection was calculated to be 1.5 µmol L(-1) (S/N=3). The binding ratio of RhC-Cr(3+) complex was determined to be 1:2 according to the Job's plot and HR-MS. The probe was successfully applied to examination of Cr(3+) in drinking water spiked samples. The average recoveries ranged from 104.9% to 106.9% at spiked concentration level of 10.00 µmol L(-1), and the obtained results were consistent with those obtained using atomic absorption spectrometry (AAS). Moreover, bioimaging experiments showed that RhC can sense the Cr(3+) in living cells with a fluorescence enhancement signal.