Controlling Two-Photon Action Cross Section by Changing a Single Heteroatom Position in Fluorescent Dyes

The optimization of nonlinear optical properties for "real-life" applications remains a key challenge for both experimental and theoretical approaches. In particular, for two-photon processes, maximizing the two-photon action cross section (TPACS), the figure of merit for two-photon bioimaging spectroscopy, requires simultaneously controlling all its components. In the present Letter, a series of difluoroborates presenting various heterocyclic rings as an electron acceptor have been synthesized and their absorption, fluorescence, photoisomerization, and two-photon absorption features have been analyzed using both experimental and theoretical approaches. Our results demonstrate that the TPACS values can be fine-tuned by changing the position of a single heteroatom, which alters the fluorescence quantum yields without changing the intrinsic two-photon absorption cross section. This approach offers a new strategy for optimizing TPACS.

Design and synthesis of a new furan-steroid-propanone derivative using some chemical strategies

There are several reports for the preparation of furan derivatives using some protocols which requires special conditions. In this way, the aim of this study was to synthesize a new furan-steroid-propanone derivative from both 17α-ethynylestradiol and 2-nitro-17α-ethynylestradiol using some series of reactions such as aldolization, 2 + 2 addition and etherification. The chemical structure was evaluated through both ¹H NMR and ¹³C NMR spectroscopic analysis. The results showed a good yielding from furan-steroid derivative. In conclusion, this investigation provides a facile synthesis of a new furan-steroid-propanone derivative, using some reagents which are not expensive and do not require special conditions for handling.

Novel NanoLuc substrates enable bright two-population bioluminescence imaging in animals

Sensitive detection of two biological events in vivo has long been a goal in bioluminescence imaging. Antares, a fusion of the luciferase NanoLuc to the orange fluorescent protein CyOFP, has emerged as a bright bioluminescent reporter with orthogonal substrate specificity to firefly luciferase (FLuc) and its derivatives such as AkaLuc. However, the brightness of Antares in mice is limited by the poor solubility and bioavailability of the NanoLuc substrate furimazine. Here, we report a new substrate, hydrofurimazine, whose enhanced aqueous solubility allows delivery of higher doses to mice. In the liver, Antares with hydrofurimazine exhibited similar brightness to AkaLuc with its substrate AkaLumine. Further chemical exploration generated a second substrate, fluorofurimazine, with even higher brightness in vivo. We used Antares with fluorofurimazine to track tumor size and AkaLuc with AkaLumine to visualize CAR-T cells within the same mice, demonstrating the ability to perform two-population imaging with these two luciferase systems.

Insights into the Role of 2-Methyl-3-furanthiol and 2-Furfurylthiol as Markers for the Differentiation of Chinese Light, Strong, and Soy Sauce Aroma Types of Baijiu

The sensory impacts of two thiols, 2-methyl-3-furanthiol (MFT) and 2-furfurylthiol (FFT), in Chinese soy sauce aroma-type Baijiu (SSB), strong aroma-type Baijiu (STB), and light aroma-type Baijiu (LTB) (liquor) were evaluated and combined with partial least squares discriminant analysis (PLS-DA) to differentiate Chinese Baijiu. The flavor dilution factors of these two thiols ranged from 81 to 6561, and quantitative results showed that MFT and FFT were significantly more abundant (p < 0.001) in SSB than in STB and LTB. The determined odor activity values (OAVs) suggest that MFT (OAV: 34-121) and FFT (OAV: 11-103) contribute significantly to the overall aroma profiles of LTB and STB. Interestingly, the OAVs of these two thiols were high (256-263) and did not significantly differ (p > 0.05) in SSB. Notably, hierarchical cluster analysis and PLS-DA results revealed that these compounds can be used to differentiate Chinese LTB, STB, and SSB. According to their prominent organoleptic and distinguishing roles, these two thiols can be regarded as flavor markers for SSB.

Diastereoisomerically Pure, (S)-O-1,2-O-isopropyli dene-(5-O-α-d-glucofuranosyl) t-butanesulfinate: Synthesis, Crystal Structure, Absolute Configuration and Reactivity

The reaction of t-butylmagnesium chlorides with diastereomerically pure (R)-1,2-O-isopropylidene-3,5-O-sulfinyl-α-d-glucofuranose (R)-4 was found to be stopped at the stage of the corresponding, diastereoisomerically pure 1,2-O-isopropylidene-(5-O-α-d-glucofuranosyl) t-butanesulfinate (S)-10 for which the crystal structure and the (S)-absolute configuration was determined by X-ray crystallography. Comparison of the absolute configurations of the starting sulfite (R)-4, and t-butanesulfinate (S)-10 (which crystallizes in the orthorhombic system, space group P212121, with the single compound molecule present in the asymmetric unit), clearly indicates that the reaction of nucleophilic substitution at the stereogenic sulfur atom in the sulfite (R)-4 occurs with the full inversion of configuration via the trigonal bipyramidal sulfurane intermediate 4c in which both the entering and leaving groups are located in apical positions.

Lignin Precipitation and Fractionation from OrganoCat Pulping to Obtain Lignin with Different Sizes and Chemical Composition

Fractionation of lignocellulose into its three main components, lignin, hemicelluloses, and cellulose, is a common approach in modern biorefinery concepts. Whereas the valorization of hemicelluloses and cellulose sugars has been widely discussed in literature, lignin utilization is still challenging. Due to its high heterogeneity and complexity, as well as impurities from pulping, it is a challenging feedstock. However, being the most abundant source of renewable aromatics, it remains a promising resource. This work describes a fractionation procedure that aims at stepwise precipitating beech wood (Fagus sp.) lignin obtained with OrganoCat technology from a 2-methyltetrahydrofuran solution, using n-hexane and n-pentane as antisolvents. By consecutive antisolvent precipitation and filtration, lignin is fractionated and then characterized to elucidate the structure of the different fractions. This way, more defined and purified lignin fractions can be obtained. Narrowing down the complexity of lignin and separately valorizing the fractions might further increase the economic viability of biorefineries.

Modulation of Glial Responses by Furanocembranolides: Leptolide Diminishes Microglial Inflammation in Vitro and Ameliorates Gliosis In Vivo in a Mouse Model of Obesity and Insulin Resistance

Neurodegenerative diseases are age-related disorders caused by progressive neuronal death in different regions of the nervous system. Neuroinflammation, modulated by glial cells, is a crucial event during the neurodegenerative process; consequently, there is an urgency to find new therapeutic products with anti-glioinflammatory properties. Five new furanocembranolides (1-5), along with leptolide, were isolated from two different extracts of Leptogorgia sp., and compound 6 was obtained from chemical transformation of leptolide. Their structures were determined based on spectroscopic evidence. These seven furanocembranolides were screened in vitro by measuring their ability to modulate interleukin-1β (IL-1β) production by microglial BV2 cells after LPS (lipopolysaccharide) stimulation. Leptolide and compounds 3, 4 and 6 exhibited clear anti-inflammatory effects on microglial cells, while compound 2 presented a pro-inflammatory outcome. The in vitro results prompted us to assess anti-glioinflammatory effects of leptolide in vivo in a high-fat diet-induced obese mouse model. Interestingly, leptolide treatment ameliorated both microgliosis and astrogliosis in this animal model. Taken together, our results reveal a promising direct biological effect of furanocembranolides on microglial cells as bioactive anti-inflammatory molecules. Among them, leptolide provides us a feasible therapeutic approach to treat neuroinflammation concomitant with metabolic impairment.

A Novel Nanoparticle Preparation to Enhance the Gastric Adhesion and Bioavailability of Xanthatin

OBJECTIVE

To prepare xanthatin (XA)-loaded polydopamine (PDA) nanoparticles (PDA-XA-NPs) and to investigate their adhesion and bioavailability.

MATERIALS AND METHODS

PDA-XA-NPs were synthesized and characterized using transmission electron microscopy, zeta potential analysis and encapsulation efficiency analysis. Their in vitro release kinetics and inhibitory effects on gastric cancer were studied. The adhesion of PDA-XA-NPs was evaluated by in vivo imaging atlas. The pharmacokinetics of PDA-XA-NPs and XA was compared.

RESULTS

PDA-XA-NPs had a spherical shape, a particle size of about 380 nm, an encapsulation efficiency of (82.1 ± 0.02) % and a drug loading capacity of (5.5 ± 0.1)%. The release of PDA-XA-NPs in PBS was stable and slow, without being affected by pH. The adhesion capacity of PDA-XA-NPs for mucin was significantly higher than that of bulk drug. The gastric mucosal retention of PDA-XA-NPs reached 89.1% which significantly exceeded that of XA. In vivo imaging showed that PDA-XA-NPs targeting the stomach were retained for a period of time. The pharmacokinetics study showed that PDA-XA-NPs had a longer retention time and a slower drug release than those of XA. In vitro experiments confirmed that PDA-XA-NPs exerted similar inhibitory effects on gastric cancer to those of XA, which lasted for a period of time.

CONCLUSION

High-adhesion NPs were constructed. Gastric cancer was targeted by orally administered PDA-XA-NPs, as a potentially feasible therapy. Eventually, the bioavailability of XA was increased.

Phytoprostanes and Phytofurans-Oxidative Stress and Bioactive Compounds-in Almonds are Affected by Deficit Irrigation in Almond Trees

Almonds have gained consumers' attention due to their health benefits (they are rich in bioactive compounds) and sensory properties. Nevertheless, information about phytoprostanes (PhytoPs) and phytofurans (PhytoFs) (new plant markers of oxidative stress and compounds with biological properties for human health) in almonds under deficit irrigation is scarce or does not exist. These compounds are plant oxylipins synthesized by the oxidation of α-linolenic acid (ALA). Besides, they are biomarkers of plant oxidative degradation and biologically active molecules involved in several plant defense mechanisms. hydroSOStainable or hydroSOS mean plant foods made from from plants under controlled water stress. Almonds are a good source of polyunsaturated fatty (PUFAs) acids, including a high content of ALA. This paper aimed to describe the influence of diverse irrigation treatments on in vitro anti-oxidant activity (AAc) and total phenolic content (TPC), as well as on the level of ALA, PhytoP, and PhytoF in "Vairo" almonds. The AAc and TPC were not affected by the irrigation strategy, while the in vivo oxidative stress makers, PhytoPs and PhytoFs, exhibited significant differences in response to water shortage. The total PhytoP and PhytoF contents ranged from 4551 to 8151 ng/100 g dry weight (dw) and from 33 to 56 ng/100 g dw, respectively. The PhytoP and PhytoF profiles identified in almonds showed significant differences among treatments. Individual PhytoPs and PhytoFs were present above the limit of detection only in almonds obtained from trees maintained under deficit irrigation (DI) conditions (regulated deficit irrigation, RDI, and sustained deficit irrigation, SDI) but not in control almonds obtained from fully irrigated trees. Therefore, these results confirm PhytoPs and PhytoFs as valuable biomarkers to detect whether an almond-based product is hydroSOStainable. As a final conclusion, it can be stated that almond quality and functionality can be improved and water irrigation consumption can be reduced if controlled DI strategies are applied in almond orchards.

Dual luminescent charge transfer probe for quantitative detection of serum albumin in aqueous samples

In diagnostic medicine serum albumin is considered as an important biomarker for assessment of cardiovascular functions and diagnosis of renal diseases. Herein, we report a novel donor-π-π-acceptor fluorophore for selective detection of serum albumin in urine samples. In our design, a phenolic donor was conjugated with a tricyanofuran (TCF) acceptor through a dimethine bridge via a simple condensation reaction. The stereoelectronic effects of the incorporated methoxy (-OCH3) groups and the TCF moiety-in conjunction with the extended π-electron conjugation-led to dual red and NIR-I absorption/emission in water. Moreover, due to superior electron transfer between a phenolate donor and the TCF acceptor and the subsequent energy decay from the charge transfer states, the fluorophore displayed negligible fluorescence emission in water and other polar solvents. Consequently, we have been able to utilize the fluorophore for quantitative estimation of serum albumin both in the red (<700 nm) and NIR-I (700-900 nm) regions of the electromagnetic spectrum with excellent reproducibility. The fluorophore selectively recognized human serum albumin over other proteins and enzymes with a limit of detection of 10 mg/L and 20 mg/L in simulated urine samples at red and NIR-I emission window of the spectrum, respectively. By molecular docking analysis and experimental displacement assays, we have shown that the selective response of the fluorophore toward human serum albumin is due to tighter supramolecular complexation between the fluorophore and the protein at subdomain IB, and the origin of the NIR-I (780 nm) emission was attributed to a twisted conformer of phenolate-π-π-TCF system in aqueous solution. These findings indicate that the fluorophore could be utilized for quantitative detection of human serum albumin in urine samples for clinical diagnosis of albuminuria.

Isolation of chemical constituents from Filago vulgaris and antiproliferative activity of the plant extract and its flavonoid against human tumor cell lines

Phytochemical investigation of the whole plant of Filago vulgaris Lam. (Asteraceae) resulted in the isolation and characterization of seven compounds, including a rare methoxylated flavonol (araneol), tetrahydrofurofuranolignans (pinoresinol and syringaresinol), p-hydroxybenzaldehyde, vanillin, vanillic acid and scopoletin. The structures of the compounds were determined by NMR and mass spectroscopy. All compounds were first obtained from this species and reported for the genus Filago. Our results demonstrate that highly methoxylated flavonols lacking substituents on ring B and lignans can be regarded as taxonomic markers for the tribe Inuleae. The lipophilic extract of F. vulgaris was found to have antiproliferative activity against HeLa cells (62.1±0.9% inhibition at 30 μ/ml), and araneol was highly effective against this tumour cell line (IC₅₀ 8.36 μ M).

Conversion of 5-Hydroxymethylfurfural into 6-(Hydroxymethyl)pyridin-3-ol: A Pathway for the Formation of Pyridin-3-ols in Honey and Model Systems

The formation of 6-(hydroxymethyl)pyridin-3-ol by ring expansion of 5-(hydroxymethyl)furfural (HMF) in the presence of ammonia-producing compounds was studied to determine the routes of formation of pyridin-3-ols in foods. 6-(Hydroxymethyl)pyridin-3-ol was produced from HMF in model systems, mostly at neutral pH values, as a function of reaction times and temperature and with an activation energy (E_a) of 74 ± 3 kJ/mol, which was higher than that of HMF disappearance (43 ± 4 kJ/mol). A reaction pathway is proposed, which is general for the formation of pyridin-3-ols from 2-oxofurans. Thus, it explains the conversions of furfural into pyridin-3-ol and of 2-acetylfuran into 2-methylpyridin-3-ol, which were also studied. When honey and sugarcane honey were heated, they produced different pyridin-3-ols, although 6-(hydroxymethyl)pyridin-3-ol was the pyridine-3-ol produced to the highest extent. Obtained results suggest that formation of pyridin-3-ols in foods is unavoidable when 2-oxofurans are submitted to thermal heating and ammonia (or ammonia-producing compounds) is present.

Total Synthesis of Pyrolaside B: Phenol Trimerization through Sequenced Oxidative C-C and C-O Coupling

A facile method to oxidatively trimerize phenols using a catalytic aerobic copper system is described. The mechanism of this transformation was probed, yielding insight that enabled cross-coupling trimerizations. With this method, the natural product pyrolaside B was synthesized for the first time. The key strategy used for this novel synthesis is the facile one-step construction of a spiroketal trimer intermediate, which can be selectively reduced to give the natural product framework without recourse to stepwise Ullmann- and Suzuki-type couplings. As a result, pyrolaside B can be obtained expeditiously in five steps and 16 % overall yield. Three other analogues were synthesized, thus highlighting the utility of the method, which provides new accessibility to this area of chemical space. A novel xanthene was also synthesized through controlled Lewis acid promoted rearrangement of a spiroketal trimer.

Isolation and Identification of Lignans and Other Phenolic Constituents from the Stem Bark of Albizia julibrissin Durazz and Evaluation of Their Nitric Oxide Inhibitory Activity

A dibenzylbutane-type lignan (16), along with eight furofuran-type (1–8), five furan-type (9–13), two dibenzylbutane-type (14 and 15), two bibenztetrahydronaphthalene-type lignans (17 and 18), two neolignans (19 and 20), and six phenolic derivatives (21–26) were isolated from an MeOH extract of the stem bark of Albizia julibrissin Durazz. The chemical structures of the obtained compounds were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) analyses. Of the evaluated compounds, 14 were isolated from A. julibrissin and the Fabaceae family for the first time. Anti-inflammatory effects of the isolated analogs were investigated in terms of the inhibition of the nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophage cells. Ten compounds (10–12, 14, and 17–22) displayed significant dose-dependent inhibitory effects against the NO production, with IC₅₀ values ranging from 5.4 to 19.2 µM. Moreover, eight compounds (1–4, 9, 13, 15, and 16) exhibited moderate inhibitory activities, with IC₅₀ values ranging from 21.0 to 62.5 µM.

Comparison of Substituting Ability of Nitronate versus Enolate for Direct Substitution of a Nitro Group

α-Nitrocinnamate underwent the conjugate addition of an active methylene compound such as nitroacetate, 1,3-dicarbonyl compound, or α-nitroketone, and the following ring closure afforded functionalized heterocyclic frameworks. The reaction of cinnamate with nitroacetate occurs via nucleophilic substitution of a nitro group by the O-attack of the nitronate, which results in isoxazoline N-oxide. This protocol was applicable to 1,3-dicarbonyl compounds to afford dihydrofuran derivatives, including those derived from direct substitution of a nitro group caused by O-attack of enolate. It was found the reactivity was lowered by an electron-withdrawing group on the carbonyl moiety. When α-nitroketone was employed as a substrate, three kinds of products were possibly formed; of these, only isoxazoline N-oxide was identified. This result indicates that the substituting ability of nitronate is higher than that of enolate for the direct S_N2 substitution of a nitro group.

Chagosensine: A Riddle Wrapped in a Mystery Inside an Enigma

The marine macrolide chagosensine is supposedly distinguished by a (Z,Z)-configured 1,3-chlorodiene contained within a highly strained 16-membered lactone ring, which also incorporates two trans-2,5-disubstituted tetrahydrofuran (THF) rings; this array is unique. After our initial synthesis campaign had shown that the originally proposed structure is incorrect, the published data set was critically revisited to identify potential mis-assignments. The "northern" THF ring and the anti-configured diol in the "southern" sector both seemed to be sites of concern, thus making it plausible that a panel of eight diastereomeric chagosensine-like compounds would allow the puzzle to be solved. To meet the challenge, the preparation of the required building blocks was optimized, and a convergent strategy for their assembly was developed. A key role was played by the cobalt-catalyzed oxidative cyclization of alken-5-ol derivatives ("Mukaiyama cyclization"), which is shown to be exquisitely chemoselective for terminal alkenes, leaving even terminal alkynes (and other sites of unsaturation) untouched. Likewise, a palladium-catalyzed alkyne alkoxycarbonylation reaction with formation of an α-methylene-γ-lactone proved instrumental, which had not found application in natural product synthesis before. Further enabling steps were a nickel-catalyzed "Tamaru-type" homocrotylation, stereodivergent aldehyde homologations, radical hydroindation, and palladium-catalyzed alkyne-1,2-bis-stannation. The different building blocks were assembled in a serial fashion to give the idiosyncratic chlorodienes by an unprecedented site-selective Stille coupling followed by copper-mediated tin/chlorine exchange. The macrolactones were closed under forcing Yamaguchi conditions, and the resulting products were elaborated into the targeted compound library. Yet, only one of the eight diastereomers turned out to be stable in the solvent mixture that had been used to analyze the natural product; all other isomers were prone to ring opening and/or ring expansion. In addition to this stability issue, our self-consistent data set suggests that chagosensine has almost certainly little to do with the structure originally proposed by the isolation team.

Inhibition of striatal-enriched protein tyrosine phosphatase by targeting computationally revealed cryptic pockets

Cryptic pockets, which are not apparent in crystallographic structures, provide promising alternatives to traditional binding sites for drug development. However, identifying cryptic pockets is extremely challenging and the therapeutic potential of cryptic pockets remains unclear. Here, we reported the discovery of novel inhibitors for striatal-enriched protein tyrosine phosphatase (STEP), a potential drug target for multiple neuropsychiatric disorders, based on cryptic pocket detection. By combining the use of molecular dynamics simulations and fragment-centric topographical mapping, we identified transiently open cryptic pockets and identified 12 new STEP inhibition scaffolds through structure-based virtual screening. Site-directed mutagenesis verified the binding of ST3 with the predicted cryptic pockets. Moreover, the most potent and selective inhibitors could modulate the phosphorylation of both ERK1/2 and Pyk2 in PC12 cells.

Synthesis, In Vitro Evaluation and Molecular Docking of the 5-Acetyl-2-aryl-6-hydroxybenzo[b]furans against Multiple Targets Linked to Type 2 Diabetes

The 5-acetyl-2-aryl-6-hydroxybenzo[b]furans 2a-h have been evaluated through in vitro enzymatic assay against targets which are linked to type 2 diabetes (T2D), namely, α-glucosidase, protein tyrosine phosphatase 1B (PTP1B) and β-secretase. These compounds have also been evaluated for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method. The most active compounds against α-glucosidase and/or PTP1B, namely, 4-fluorophenyl 2c, 4-methoxyphenyl 2g and 3,5-dimethoxyphenyl substituted 2h derivatives were also evaluated for potential anti-inflammatory properties against cyclooxygenase-2 activity. The Lineweaver-Burk and Dixon plots were used to determine the type of inhibition on compounds 2c and 2h against α-glucosidase and PTP1B receptors. The interactions were investigated in modelled complexes against α-glucosidase and PTP1B via molecular docking.

Human transport of thirdhand tobacco smoke: A prominent source of hazardous air pollutants into indoor nonsmoking environments

The contamination of indoor nonsmoking environments with thirdhand smoke (THS) is an important, poorly understood public health concern. Real-time THS off-gassing from smokers into a nonsmoking movie theater was observed with online and offline high-resolution mass spectrometry. Prominent emission events of THS tracers (e.g., 2,5-dimethylfuran, 2-methylfuran, and acetonitrile) and other tobacco-related volatile organic compounds (VOCs) coincided with the arrival of certain moviegoers and left residual contamination. These VOC emission events exposed occupants to the equivalent of 1 to 10 cigarettes of secondhand smoke, including multiple hazardous air pollutants (e.g., benzene and formaldehyde) at parts-per-billion concentrations. Nicotine and related intermediate-volatility nitrogen-containing compounds, which vaporized from clothes/bodies and recondensed onto aerosol, comprised 34% of observed functionalized organic aerosol abundance. Exposure to THS VOC emission events will be considerably enhanced in poorly ventilated or smaller spaces in contrast with a large, well-ventilated theater-amplifying concentrations and potential impacts on health and indoor chemistry.

19-nor-, 20-nor-, and tetranor-Halimane-Type Furanoditerpenoids from Croton crassifolius

The phytochemical investigation of the roots of Croton crassifolius led to the isolation of 16 new halimane furanoditerpenoids, crohalifuranes A-P (1-16), along with 15 known analogues, 17-31. The new structures including their absolute configurations were elucidated by NMR and MS data analysis, comparison of experimental and calculated electronic circular dichroism data, single-crystal X-ray diffraction data, and chemical methods. Crohalifuranes A (1) and B (2) are tetranor- and 19-nor-halimane diterpenoids featuring a rare decahydroacenaphthene core, respectively, which might be derived from the accompanying crassifoliusin A by loss of the furan ring or the C-19 substituent. Crohalifurane C (3) represents the first example of a 20-nor-halimane diterpenoid, and crohalifurane D (4) is characterized by an unusual 6,20-δ-lactone moiety. All compounds were examined for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide in RAW264.7 cells, and 2 and 23 exhibited moderate inhibition on NO production with IC₅₀ values of 17.2 ± 1.3 and 23.7 ± 1.4 μM, respectively.

Iron-Catalysed C(sp2)-H Borylation Enabled by Carboxylate Activation

Arene C(sp²)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp²)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.

New ruthenium polypyridyl complexes functionalized with fluorine atom or furan: Synthesis, DNA-binding, cytotoxicity and antitumor mechanism studies

Two novel ruthenium(II) polypyridyl complexes, namely, [Ru(dmp)₂(CAPIP)](ClO₄)₂ (Ru(II)-1) and [Ru(dmp)₂(CFPIP)](ClO₄)₂ (Ru(II)-2), which respectively contain (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phen-anthroline (CAPIP) and (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline. (CFPIP), were first designed and characterized (dmp = 2,9-dimethyl-1,10-phenanthroline). DNA binding experiments indicated that Ru(II) complexes interact with CT DNA through intercalative mode. In addition, the complexes Ru(II)-1 and Ru(II)-2, showed remarkable cell cytotoxicity, giving the respective IC₅₀ values of 4.1 ± 1.4 μM and 6.1 ± 1.4 μM on the A549 cancer cells. These values indicated higher activity than CAPIP, CFPIP, cisplatin (8.2 ± 1.4 μM) and other corresponding Ru(II) polypyridyl complexes. Furthermore, the Ru(II) complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. Significantly, complexes Ru(II)-1 and Ru(II)-2 induced A549 cells apoptosis was mediated by increase of ROS levels and dysfunction of mitochondria, and resulted in cell cycle arrest and increased anti-migration activity on A549 cells. Overall, these results indicated that complexes Ru(II)-1 and Ru(II)-2 could be suitable candidates for further investigation as a chemotherapeutic agent in the treatment of tumors.

Formal [3+2] Cycloaddition Reactions of Electron-Rich Aryl Epoxides with Alkenes under Lewis Acid Catalysis Affording Tetrasubstituted Tetrahydrofurans

We report on the regio- and stereoselective synthesis of tetrahydrofurans by reaction between epoxides and alkenes in the presence of a Lewis acid. This is an unprecedented formal [3+2] cycloaddition reaction between an epoxide and an alkene. The chemical reaction represents a very concise synthesis of tetrahydrofurans from accessible starting compounds.

Pharmacological characterization of high-affinity σ1 receptor ligands with spirocyclic thienopyran and thienofuran scaffold

OBJECTIVES

In this study, the pharmacological properties of six spirocyclic piperidines 1-6 showing very high σ1 receptor affinity (Ki  = 0.2-16 nm) were investigated.

METHODS

In vitro receptor binding studies, retinal ganglion assay and in vivo capsaicin assay were used to determine the affinity, selectivity and activity. Influence on human tumour cell growth (cell lines A427, LCLC-103H, 5637 and DAN-G) was determined in different assays. The effect on the ergosterol and cholesterol biosynthesis was determined by GLC/MS analysis.

KEY FINDINGS

Receptor binding studies demonstrated high selectivity for the σ1 receptor. The increased Ca2+ influx mediated by 2 and the analgesic activity of 1, 4, 5 and 6 confirm σ1 receptor antagonistic activity. Inhibition of human tumour cell growth further supports the σ1 antagonistic effects. Treatment of A427 tumour cells with 2 led to cell detachment and cell degradation. Whereas the ergosterol biosynthesis was not affected, the sterol C14-reductase, a key enzyme in the cholesterol biosynthesis, was weakly inhibited.

CONCLUSIONS

Due to the high selectivity, off-target effects are not expected. The antiallodynic activity underlines the clinical potential of the spirocyclic piperidines for the treatment of neuropathic pain. Due to the antiproliferative activity, the spirocyclic σ1 antagonists represent promising antitumour agents.

Effective Biobased Phosphorus Flame Retardants from Starch-Derived bis-2,5-(Hydroxymethyl)Furan

A series of biobased phosphorus flame retardants has been prepared by converting starch-derived bis-2,5-(hydroxymethyl)furan to the corresponding diacrylate followed by Michael addition of phosphite to generate derivatives with phosphorus moieties attached via P–C bonds. All compounds behave as effective flame retardants in DGEBA epoxy resin. The most effective is the DOPO derivative, 2,5-di[(3-dopyl-propanoyl)methyl]furan. When incorporated into a DGEBA blend at a level to provide 2% phosphorus, a material displaying a LOI of 30, an UL 94 rating of V0 and a 40% reduction in combustion peak heat release rate compared to that for resin containing no additive is obtained. The analogous compounds generated from bisphenol A and tetrabromobisphenol A exhibit similar flame-retarding properties.

Ultrasonic modification of pectin for enhanced 2-furfurylthiol encapsulation: process optimization and mechanisms

BACKGROUND

Pectin is an intriguing polymer, which is usually regarded as a byproduct from agricultural and biological processes. In previous studies, ultrasound treatment has been explored to improve the functionality of pectin but most of that work focused on aspects of molecular structure and the chemical properties of pectin. In this study, we utilized ultrasound treatment to modify the physiochemical properties of pectin. Using ultrasound treatment, we evaluated the emulsifying capability of pectin as a function of ultrasonic time and power density, using a response surface approach. A very potent yet unstable coffee-like aroma compound, 2-furfurylthiol, was also used for comparing the encapsulation feasibility of emulsion made with original pectin and ultrasound-treated pectin.

RESULTS

Our results showed that the particle size of pectin was highly correlated with power density and ultrasound time. Approximately 370 nm of pectin particle size could be reached at a power density of 1.06 W mL^-1 for 40 min. Ultrasound treatment increased emulsion droplet size but significantly improved emulsifying capacities, such as centrifugal stability and surface loading, although it was highly dependent upon the ultrasound treatment condition. When used as the encapsulation wall material, the ultrasound-modified pectin had significantly enhanced performance compared with the original, in terms of flavor retention over time at 45 °C and 65 °C.

CONCLUSION

Ultrasound treatment was able to modify the physiochemical properties of pectin, which thus improved emulsification stability and encapsulation feasibility by forming a thicker layer at the oil / water interface to protect the core materials. © 2019 Society of Chemical Industry.

Regioselective and stereoselective synthesis of epithiomethanoiminoindeno[1,2-b]furan-3-carbonitrile: heterocyclic [3.3.3]propellanes

Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides, furnished (3aR,8bS,Z)-2-amino-9-substituted-10-(2-(2,4-dinitrophenyl)hydrazono)-4-oxo-4H-3a,8b-(epithiomethanoimino)indeno[1,2-b]furan-3-carbonitrile as a type of (2,4-dinitrophenyl)hydrazono[3.3.3]propellanes in good yields as single diastereomers. Structure determination and confirmation of the synthesized products have been achieved using various and modern spectroscopic techniques such as IR, NMR (¹H NMR and ¹³C NMR), mass spectrometry, as well as X-ray crystal analysis. The X-ray structure data cleared that the molecule of 7a was crystalized as monoclinic, space group C2/c (no.15).

The Structural and Magnetic Properties of FeII and CoII Complexes with 2-(furan-2-yl)-5-pyridin-2-yl-1,3,4-oxadiazole

Two novel coordination compounds containing heterocyclic bidentate N,N-donor ligand 2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (fpo) were synthesized. A general formula for compounds originating from perchlorates of iron, cobalt, and fpo can be written as: [M(fpo)₂(H₂O)₂](ClO₄)₂ (M = Fe(II) for (1) Co(II) for (2)). The characterization of compounds was performed by general physico-chemical methods-elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) in case of organics, and single crystal X-ray diffraction (sXRD). Moreover, magneto-chemical properties were studied employing measurements in static field (DC) for 1 and X-band EPR (Electron paramagnetic resonance), direct current (DC), and alternating current (AC) magnetic measurements in case of 2. The analysis of DC magnetic properties revealed a high spin arrangement in 1, significant rhombicity for both complexes, and large magnetic anisotropy in 2 (D = -21.2 cm^-1). Moreover, 2 showed field-induced slow relaxation of the magnetization (U_eff = 65.3 K). EPR spectroscopy and ab initio calculations (CASSCF/NEVPT2) confirmed the presence of easy axis anisotropy and the importance of the second coordination sphere.

Melanoidins Formed by Heterocyclic Maillard Reaction Intermediates via Aldol Reaction and Michael Addition

Thermal treatment of food leads to the formation of melanoidins by reactions of carbohydrates with free amino acids or proteins in the late stage of Maillard reaction. The aim of this study was the identification of reaction mechanisms responsible for the formation of melanoidins involving active methylenes with the heterocyclic structure and the structural characterization of the resulting products. For this purpose, norfuraneol was incubated with the aldehydes pyrrole-2-aldehyde or furfural at 125 °C. With the help of high-resolution mass spectrometry, the structural composition of oligomers of up to fifteen C₅-units could be described for the first time. Aldol and Michael reactions could be identified as crucial steps for the formation of new C-C-bonds. With increasing heating time, the elimination of water from the products was facilitated, and oxidation reactions of integrated reductone structures lead to the expansion of conjugated double-bond systems responsible for the color formation of the samples.

Thermodynamic and Kinetic Study of Diels-Alder Reaction between Furfuryl Alcohol and N-Hydroxymaleimides-An Assessment for Materials Application

The study of Diels–Alder reactions in materials science is of increasing interest. The main reason for that is the potential thermoreversibility of the reaction. Aiming to predict the behavior of a material modified with maleimido and furyl moieties, ¹H NMR and UV-Vis solution studies of the Diels–Alder reaction between furfuryl alcohol and two N-hydroxymaleimides are explored in the present study. Rate constants, activation energy, entropy, and enthalpy of formation were determined from each technique for both reacting systems. Endo and exo isomers were distinguished in ¹H NMR, and the transition from a kinetic, controlled Diels–Alder reaction to a thermodynamic one could be observed in the temperature range studied. A discussion on the effect of that on the application in a material was performed. The approach selected considers a simplified equilibrium of the Diels–Alder reaction as the kinetic model, allowing materials scientists to evaluate the suitability of using the reacting molecules for the creation of thermoresponsive materials. The proposed approach determines the kinetic constants without the direct influence of the equilibrium constant value, thereby allowing a more objective data analysis. The effects of the selection of kinetic model, analytical method, and data treatment are discussed.

Oxidized Products of α-Linolenic Acid Negatively Regulate Cellular Survival and Motility of Breast Cancer Cells

Despite recent advances in our understanding of the biological processes leading to the development and progression of cancer, there is still a need for new and effective agents to treat this disease. Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are non-enzymatically oxidized products of α-linolenic acid that are present in seeds and vegetable oils. They have been shown to possess anti-inflammatory and apoptosis-promoting activities in macrophages and leukemia cells, respectively. In this work, seven PhytoPs (PP1–PP7) and one PhytoFs (PF1) were evaluated for their cytotoxic, chemosensitization, and anti-migratory activities using the MCF-7 and MDA-MB-231 breast cancer cell lines. Among the tested compounds, only three PhytoPs had a significant effect on cell viability compared to the control group: Ent-9-L₁-PhytoP (PP6) decreased cell viability in both cell lines, while 16-F_1t-PhytoP (PP1) and 9-L₁-PhytoP (PP5) decreased viability of MCF-7 and MDA-MB-231 cells, respectively. When combined with a sub-cytotoxic dose of doxorubicin, these three PhytoPs displayed significantly enhanced cytotoxic effects on MCF-7 cells while the chemotherapeutic drug alone had no effect. In cellular motility assays, Ent-9-(RS)-12-epi-ST-Δ¹⁰-13-PhytoF could significantly inhibit cellular migration of MDA-MB-231 cells. In addition, Ent-9-(RS)-12-epi-ST-Δ¹⁰-13-PhytoF also enhanced cellular adhesion of MDA-MB-231 cells.

QSAR Model of Indeno[1,2-b]indole Derivatives and Identification of N-isopentyl-2-methyl-4,9-dioxo-4,9-Dihydronaphtho[2,3-b]furan-3-carboxamide as a Potent CK2 Inhibitor

Casein kinase II (CK2) is an intensively studied enzyme, involved in different diseases, cancer in particular. Different scaffolds were used to develop inhibitors of this enzyme. Here, we report on the synthesis and biological evaluation of twenty phenolic, ketonic, and para-quinonic indeno[1,2-b]indole derivatives as CK2 inhibitors. The most active compounds were 5-isopropyl-1-methyl-5,6,7,8-tetrahydroindeno[1,2-b]indole-9,10-dione 4h and 1,3-dibromo-5-isopropyl-5,6,7,8-tetrahydroindeno[1,2-b]indole-9,10-dione 4w with identical IC₅₀ values of 0.11 µM. Furthermore, the development of a QSAR model based on the structure of indeno[1,2-b]indoles was performed. This model was used to predict the activity of 25 compounds with naphtho[2,3-b]furan-4,9-dione derivatives, which were previously predicted as CK2 inhibitors via a molecular modeling approach. The activities of four naphtho[2,3-b]furan-4,9-dione derivatives were determined in vitro and one of them (N-isopentyl-2-methyl-4,9-dioxo-4,9-dihydronaphtho[2,3-b]furan-3-carboxamide) turned out to inhibit CK2 with an IC₅₀ value of 2.33 µM. All four candidates were able to reduce the cell viability by more than 60% after 24 h of incubation using 10 µM.

Bio-Based Thermo-Reversible Aliphatic Polycarbonate Network

Aliphatic polycarbonates represent an important class of materials with notable applications in the biomedical field. In this work, low Tg furan-functionalized bio-based aliphatic polycarbonates were cross-linked thanks to the Diels-Alder (DA) reaction with a bis-maleimide as the cross-linking agent. The thermo-reversible DA reaction allowed for the preparation of reversible cross-linked polycarbonate materials with tuneable properties as a function of the pendent furan content that was grafted on the polycarbonate backbone. The possibility to decrosslink the network around 70 °C could be an advantage for biomedical applications, despite the rather poor thermal stability of the furan-functionalized cross-linked polycarbonates.

Generation of α-Diketones and 4-Hydroxy-2,5-dimethyl-3(2H)-furanone upon Coffee Roasting-Impact of Roast Degree on Reaction Pathways

The formation pathways of α-diketones (2,3-butanedione and 2,3-pentanedione) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) upon coffee roasting were investigated in a kinetic study applying labeled and unlabeled sucrose (CAMOLA approach) in biomimetic in-bean experiments. The results highlighted that not only did the contribution of sucrose to the level of α-diketones in roasted coffee change with the roasting degree but also the portion of the individual reaction pathways. At early roasting stages, 2,3-butanedione was formed from sucrose mainly via the intact sugar skeleton, whereas from the middle of the roasting course, the formation foremost occurred from sugar fragments, primarily by C₁/C₃ and C₂/C₂ recombinations. In contrast, 2,3-pentanedione was generated from sucrose mainly via an intact sugar skeleton during the whole roasting cycle; nevertheless, the share of 2,3-pentanedione formed by recombination of fragments (mainly C₂/C₃) progressively increased with roasting time. HDMF was generated from sucrose almost exclusively via cyclization of an intact skeleton, irrespective of the roast time.

A New Valuable Synthesis of Polyfunctionalized Furans Starting from β-Nitroenones and Active Methylene Compounds

Highly functionalized furans are the key scaffolds of many pharmaceuticals and bioactive natural products. Herein, we disclose a new fruitful synthesis of polyfunctionalized furans starting from β-nitroenones and α-functionalized ketones. The protocol involves two steps promoted by solid supported species, and it provides the title targets from satisfactory to very good overall yields and in an excellent diastereomeric ratios.

Comparing and Contrasting the Multiple Roles of Butenolide Plant Growth Regulators: Strigolactones and Karrikins in Plant Development and Adaptation to Abiotic Stresses

Strigolactones (SLs) and karrikins (KARs) are both butenolide molecules that play essential roles in plant growth and development. SLs are phytohormones, with SLs having known functions within the plant they are produced in, while KARs are found in smoke emitted from burning plant matter and affect seeds and seedlings in areas of wildfire. It has been suggested that SL and KAR signaling may share similar mechanisms. The α/β hydrolases DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2), which act as receptors of SL and KAR, respectively, both interact with the F-box protein MORE AXILLARY GROWTH 2 (MAX2) in order to target SUPPRESSOR OF MAX2 1 (SMAX1)-LIKE/D53 family members for degradation via the 26S proteasome. Recent reports suggest that SLs and/or KARs are also involved in regulating plant responses and adaptation to various abiotic stresses, particularly nutrient deficiency, drought, salinity, and chilling. There is also crosstalk with other hormone signaling pathways, including auxin, gibberellic acid (GA), abscisic acid (ABA), cytokinin (CK), and ethylene (ET), under normal and abiotic stress conditions. This review briefly covers the biosynthetic and signaling pathways of SLs and KARs, compares their functions in plant growth and development, and reviews the effects of any crosstalk between SLs or KARs and other plant hormones at various stages of plant development. We also focus on the distinct responses, adaptations, and regulatory mechanisms related to SLs and/or KARs in response to various abiotic stresses. The review closes with discussion on ways to gain additional insights into the SL and KAR pathways and the crosstalk between these related phytohormones.

Direct Vicinal Difunctionalization of Thiophenes Enabled by the Palladium/Norbornene Cooperative Catalysis

Herein we report a direct vicinal difunctionalization of thiophenes via the palladium/norbornene (Pd/NBE) cooperative catalysis. A series of mono- and disubstituted thiophenes can be difunctionalized site-selectively and regioselectively at the C4 and C5 positions in good yields, enabled by an arsine ligand and a unique amide-based NBE. The synthetic utility has been shown in derivatizations of complex bioactive compounds and an open-flask gram-scale preparation. Preliminary results have been obtained in the difunctionalization of furans and a direct C4-selective arylation of 2-substituted thiophenes.

Synthesis and Electrochemistry of New Furylpyrazolino[60]fullerene Derivatives by Efficient Microwave Radiation

Efficient one-pot synthesis of new series of furylpyrazolino[60]fullerene derivatives was prepared by [3 + 2] cycloaddition reaction mediated with (diacetoxyiodo)benzene (PhI(OAc)₂) as an oxidant in o-dichlorobenzene (ODCB) under microwave irradiation. Different techniques have been used to confirm the structural identity including FT-IR, fast atom bombardment (FAB)-mass, NMR, and single-crystal X-ray diffraction, in addition to investigating the photophysical properties and the electrochemical properties for the new compounds using UV-Vis spectra, fluorescence spectra, cyclic voltammetry, and square wave voltammetry. Three of these pyrazolino[60]fullerene compounds showed better electron affinity than the parent C₆₀ in the ground state.

TiCl4 catalyzed cleavage of (25R)-22-oxo-23-spiroketals. Synthesis of sapogenins with furostanol and pyranone E rings on the side chain

The regioselective opening of the F ring of 22-oxo-23-spiroketals 7a-d using TiCl₄ in acetic anhydride yielded the novel furostanols 11a-d along with cholestanic derivatives 8a-d with pyranone E ring. The structures of the new derivatives thus obtained were established using one- (DEPT) and two-dimensional ¹H, ¹³C NMR experiments (COSY, HSQC, HMBC, NOESY). The 22α-hydroxyl orientation in compounds 11a-d was proposed by comparison of the ¹³C chemical shifts with those of other aglycone members of this family, and confirmed by combined NOESY and X-ray diffraction analysis of compound 11a.

Destruction of dioxin and furan pollutants via electrophilic attack of singlet oxygen

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) remain of particular concern owing to their extensive toxicity towards health and accumulation in the environment. Atmospheric oxidation (by ambient oxygen molecules) of this class of persistent environmental pollutants has little to no kinetic feasibility due to very sizable activation energies in the entrance channel. The current control measures involve energy-intensive source incineration of contaminated materials at high temperatures as high as 850 °C. This study finds an alternative low-energy approach of destroying dioxin-like compounds, proposing that advanced oxidation by highly reactive singlet oxygen (O₂¹Δ_g, originated from chemical, surface-mediated and photochemical processes) can initiate low-temperature remediation of these pollutants. This contribution completes the first milestone in mapping out the mechanisms of the electrophilic addition of singlet oxygen to unsubstituted and chlorinated dibenzo-p-dioxin (DBD) and dibenzofuran (DBF) structures, according to density functional theory DFT-B3LYP method in conjunction with the 6-311+g(d,p) basis set, as well as energy refinements based on the approximate spin-projection scheme. The [2+2]-cycloaddition mechanism appears dominant for singlet oxidation of dibenzo-p-dioxin with a fitted rate constant of k(T) = 5.01 × 10^-14 exp(-98000/RT). On the other hand, the addition of singlet oxygen to the aromatic ring of dibenzofuran primarily transpires via [4+2]-cycloaddition channel with a fitted rate constant of k(T) = 2.16 × 10^-13 exp(-119000/RT). The results suggest that application of singlet oxygen can reduce the energy cost of recycling halogenated and flame retarded materials.

Nonadride and Spirocyclic Anhydride Derivatives from the Plant Endophytic Fungus Talaromyces purpurogenus

Six new nonadride derivatives (1-6) and three new spirocyclic anhydride derivatives (7-9) were isolated from the endophytic fungus Talaromyces purpurogenus obtained from fresh leaves of the toxic medicinal plant Tylophora ovata. The structures of these compounds were determined by spectroscopic analyses including 1D and 2D NMR, HRESIMS, and ECD techniques. Maleic anhydride derivatives 1-9 were evaluated for their in vitro anti-inflammatory activities. Compound 1 showed significant inhibitory activity against NO production in LPS-induced RAW264.7 cells with an IC₅₀ value of 1.9 μM. Compounds 2 and 6 showed moderate inhibitory activities toward XOD and PTP1b, respectively, at 10 μM with inhibition rates of 67% and 76%.

A Simple, Efficient, and Eco-Friendly Method for the Preparation of 3-Substituted-2,3-dihydroquinazolin-4(1H)-one Derivatives

A simple, cost-effective method under environmentally benign conditions is a very important concept for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives. The present work describes an efficient and eco-friendly protocol for the synthesis of 2-amino-N-(2-substituted-ethyl)benzamide and 3-substituted-2,3-dihydroquinazolin-4(1H)-one derivatives. The novel feature of this protocol is the use of 2-methyl tetrahydrofuran (2-MeTHF) as an eco-friendly alternative solvent to tetrahydrofuran (THF) in the first step. In the second step, methanol in the presence of potassium carbonate as a catalyst was used under conventional heating or microwave irradiation, which provided an eco-friendly method to afford the target products in excellent yields and purities. NMR (1H and 13C), elemental analysis, and LC-MS confirmed the structures of all compounds. X-ray crystallography further confirmed the structure of the intermediate 2-amino-N-(2-substituted-ethyl)benzamide 3a. The molecular structure of 3a was monoclinic crystal, with P21/c, a = 13.6879 (11) Å, b = 10.2118 (9) Å, c = 9.7884 (9) Å, β = 105.068 (7)°, V = 1321.2 (2) Å3, and Z = 4.

One-Pot Enzyme Cascade for Controlled Synthesis of Furancarboxylic Acids from 5-Hydroxymethylfurfural by H2 O2 Internal Recycling

Furancarboxylic acids are promising biobased building blocks in pharmaceutical and polymer industries. In this work, dual-enzyme cascade systems composed of galactose oxidase (GOase) and alcohol dehydrogenases (ADHs) are constructed for controlled synthesis of 5-formyl-2-furancarboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF), based on the catalytic promiscuity of ADHs. The byproduct H₂ O₂ , which is produced in GOase-catalyzed oxidation of HMF to 2,5-diformylfuran (DFF), is used for horseradish peroxidase (HRP)-mediated regeneration of the oxidized nicotinamide cofactors for subsequent oxidation of DFF promoted by an ADH, thus implementing H₂ O₂ internal recycling. The desired products FFCA and FDCA are obtained with yields of more than 95 %.

Synthesis and evaluation of 2,5-furan, 2,5-thiophene and 3,4-thiophene-based derivatives as CXCR4 inhibitors

The interaction between G-Protein coupled receptor CXCR4 and its natural ligand CXCL12 has been linked to inflammation experienced by patients with Irritable Bowel Disease (IBD). Blocking this interaction could potentially reduce inflammatory symptoms in IBD patients. In this work, several thiophene-based and furan-based compounds modeled after AMD3100 and WZ811-two known antagonists that interrupt the CXCR4-CXCL12 interaction-were synthesized and analyzed. Fifteen hit compounds were identified; these compounds exhibited effective concentrations (EC) lower than 1000 nM (AMD3100) and inhibited invasion of metastatic cells by at least 45%. Selected compounds (2d, 2j, 8a) that inhibited metastatic invasion at a higher rate than WZ811 (62%) were submitted for a carrageenan inflammation test, where both 8a and 2j reduced inflammation in the same range as WZ811 (40%) but did not reduce inflammation more than 40%. Select compounds were also modeled in silico to show key residue interactions. These preliminary results with furan-based and thiophene-based analogues contribute to the new class on heterocyclic aromatic-based CXCR4 antagonists.

Ginkgolide B and bilobalide promote the growth and increase β-catenin expression in hair follicle dermal papilla cells of American minks

The regeneration of proliferation potential of dermal papilla (DP) cells contributes to the treatment of hair loss disorders. Ginkgolide B (GKB) and bilobalide (BB) are two functional components isolated from Ginkgo biloba that can promote hair growth. In the current study, the effect of GKB or BB on DP cell viability and the related signaling was assessed. Hair follicles were isolated from minks, and the growth of hair follicles was measured under the administration of GKB or BB. DP cells isolated from minks were also subjected to GKB or BB. The administration of GKB or BB induced the growth of hair follicles. The viability of DP cells was also increased by GKB or BB as illustrated by methyl thiazolyl tetrazolium and flow cytometry detection. Moreover, the secretion of VEGF was enhanced by GKB or BB. At molecular level, the activities of Akt, ERK1/2, and β-catenin were induced by GKB, whereas BB only increased the activities of Akt and β-catenin. In conclusion, although the two components influenced the β-catenin signaling activity in distinct mechanisms, they both increased the viability of DP cells and promoted the cycle of hair follicles.

Novel S-Thiazol-2-yl-furan-2-carbothioate Derivatives as Potential T3SS Inhibitors Against Xanthomonas oryzae on Rice

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is considered as the most destructive disease of rice. The use of bactericides is among the most widely used traditional methods to control this destructive disease. The excessive and repeated use of the same bactericides is also becoming the reason behind the development of bactericide resistance. The widely used method for finding the new antimicrobial agents often involves the bacterial virulence factors as a target without affecting bacterial growth. Type III secretion system (T3SS) is a protein appendage and is considered as having essential virulence factors in most Gram-negative bacteria. Due to the conserved construct, T3SS has been regarded as an important mark for the blooming of novel antimicrobial drugs. Toward the search of new T3SS inhibitors, an alternative series of 1,3-thiazole derivatives were designed and synthesized. Their structures were characterized and confirmed by ¹H NMR, ¹³C NMR, MS, and elemental analysis. All the title compounds inhibited the promoter activity of hpa1 gene significantly. Eight of them showed better inhibition than our previous T3SS inhibitor TS006 (o-coumaric acid, OCA). The treatment of Xoo with eight compounds significantly attenuated HR without affecting bacterial growth. The mRNA levels of some representative genes (hrp/hrc genes) were reduced up to different extents. In vivo bioassay results showed that eight T3SS inhibitors could reduce bacterial leaf blight and bacterial leaf streak symptoms on rice, significantly.

Direct 1H NMR Quantitation of Valuable Furan Fatty Acids in Fish Oils and Fish Oil Fractions

Furan fatty acids (FuFAs) are a class of naturally occurring minor fatty acids with fish as the richest food source. Typically, FuFA analysis is cumbersome and involves several steps. We developed a quantitative ¹H NMR method (qNMR) in which fish oil samples were directly measured after dilution with CDCl₃ stabilized with silver (which was essential to prevent formation of radicals) and addition of an internal standard. The singlet at δ = 1.89 ppm was suitable for quantitation of monomethyl FuFAs, whereas the signal at δ = 1.83 ppm was suitable to quantitate dimethyl FuFAs. Using standard NMR tubes with 650 μL solvent, the limit of quantitation was 0.5 μg (dimethyl FuFAs) and 1.0 μg (monomethyl FuFAs). Applied to three fish oil and two enriched fish oil samples (sample weight, 10 mg), the final qNMR method resulted in similar total FuFA contents as determined in parallel by gas chromatography coupled to mass spectrometry.

Fabrication of Furan-Functionalized Quinazoline Hybrids: Their Antibacterial Evaluation, Quantitative Proteomics, and Induced Phytopathogen Morphological Variation Studies

The limited number of agrochemicals targeting plant bacterial diseases has driven us to develop highly efficient, low-cost, and versatile antibacterial alternatives. Herein, a novel type of simple furan-functionalized quinazolin-4-amines was systematically fabricated and screened for their antibacterial activity. Bioassay results revealed that compounds C₁ and E₄ could substantially block the growth of two frequently mentioned pathogens Xanthomonas oryzae pv oryzae and X. axonopodis pv citri in vitro, displaying appreciable EC₅₀ values of 7.13 and 10.3 mg/L, respectively. This effect was prominently improved by comparing those of mainly used agrochemicals. An in vivo experiment against bacterial blight further illustrated their viable applications as antimicrobial ingredients. Quantitative proteomics demonstrated that C₁ possessed a remarkable ability to manipulate the upregulation and downregulation of expressed proteins, which probably involved d-glucose and biotin metabolic pathways. This finding was substantially verified by parallel reaction monitoring analysis. Scanning electron microscopy images and fluorescence spectra also indicated that the designed compounds had versatile capacities for destroying the integrity of bacteria. Given these remarkable characteristics, furan-functionalized quinazoline hybrids can serve as a viable platform for developing innovative antibiotic alternatives against bacterial infections.

2(5H)-Furanone sesquiterpenes from Eremophila bignoniiflora: High-resolution inhibition profiling and PTP1B inhibitory activity

Eremophila bignoniiflora is a shrub distributed throughout inland northern and eastern Australia, and it has been used in several medicinal applications by some Australian Aboriginal people. In our continued search for anti-diabetic constituents from natural resources, the crude ethyl acetate extract of E. bignoniiflora was found to have protein-tyrosine phosphatase 1B (PTP1B) inhibitory activity with an IC₅₀ value of 23.9 ± 1.9 μg/mL. High-resolution PTP1B inhibition profiling combined with HRMS and NMR were subsequently used to investigate the individual compounds responsible for the observed bioactivity of the crude extract. This led to identification of five undescribed 2(5H)-furanone sesquiterpenes, together with 13 flavonoids and phenolic compounds. Dose-response curves of the isolated compounds revealed that two 2(5H)-furanone sesquiterpene cinnamates and three flavonoids exhibited moderate PTP1B inhibitory activity with IC₅₀ values from 41.4 ± 1.4 to 154.5 ± 8.9 μM.

Novel tetrahydrofuran (THF) degradation-associated genes and cooperation patterns of a THF-degrading microbial community as revealed by metagenomic

Our understanding of the tetrahydrofuran (THF) degradation in complex environment is limited. The majority of THF degrading genes reported are group V soluble diiron monooxygenases and share greater than 95% homology with one another. In this study, we used sole-carbon-source incubation combined with high-throughput metagenomic sequencing to investigate this contaminant's degradation in environmental samples. We identified as-yet-uncultivated microbe from the genera Pseudonocardia and fungi Scedosporium sp. (Scedosporium sp. was successfully isolated) as THF degraders as containing THF degradation genes, while microbes from the genera Bordetella, Pandoraea and Rhodanobacter functioned as main cooperators by utilizing acidic intermediates and providing anti-acid mechanisms. Furthermore, a 9387-bp THF degradation cluster designated thmX from the as-yet-uncultivated Pseudonocardia (with 6 main ORFs and with 79-93% amino acid sequence identity with previously reported clusters) was discovered. We also found a THF-degrading related cytochrome P450 monooxygenase from the genus Scedosporium and predicted its cognate reductase for the first time. All the genes and clusters mentioned above were successfully amplified from samples and cloned into the suitable expression vectors. This study will provide novel insights for understanding of THF degradation mechanisms under acid stress conditions and mining new THF degradation genes.