Synthesis, antifungal activity and 3D-QSAR study of novel acyl thiourea compounds containing gem-dimethylcyclopropane ring.

A series of novel acyl thiourea compounds containing gem-dimethylcyclopropane ring were designed and synthesized by multi-step reactions in search of novel antifungal molecules. Structures of all the target compounds were characterized by spectral techniques of UV-vis, FT-IR, 1H-NMR, 13C-NMR, and ESI-MS. The antifungal activity of the target compounds was preliminarily evaluated by agar dilution method. The antifungal bioassay revealed that, at 50 µg/mL, compounds 5h (R = o-F), 5m (R = p-Br), and 5n (R = o-NO2) showed the same antifungal activity of 73.6% against Physalospora piricola, which was comparable than that of the positive control. Furthermore, against Gibberella zeae, compounds 5k (R = m-Cl), 5l (R = m-Br), 5m (R = p-Br), and 5n (R = o-NO2) displayed the same antifungal activity of 75.6%, and compound 5o (R = p-NO2) displayed antifungal activity of 78.8%, which were all better than that of the positive control. The preliminary analysis of 3D-QSAR model was performed to study the effect of molecular structure on biological activity using the comparative molecular field analysis (CoMFA) method. The results showed 3D-QSAR model (r2 = 0.995, q2 = 0.503) was reasonable and effective.

Synthesis and Antiproliferative Evaluation of Novel Hybrids of Dehydroabietic Acid Bearing 1,2,3-Triazole Moiety.

To discover novel potent cytotoxic diterpenoids, a series of hybrids of dehydroabietic acid containing 1,2,3-triazole moiety were designed and synthesized. The target compounds were characterized by means of FT-IR, 1H NMR, 13C NMR, ESI-MS and elemental analysis techniques. The in vitro cytotoxicity of these compounds was evaluated by standard MTT (methyl thiazolytetrazolium) assay against CNE-2 (nasopharynx), HepG2 (liver), HeLa (epithelial cervical), BEL-7402 (liver) human carcinoma cell lines and human normal liver cell (HL-7702). The screening results revealed that most of the hybrids showed significantly improved cytotoxicity over parent compound DHAA. Among them, [1-(3-fluorobenzyl)-1H-1,2,3-triazole-4-yl]dehydroabietic acid methyl ester (3c), and [1-(2-nitrobenzyl)-1H-1,2,3-triazole-4-yl]dehydroabietic acid methyl ester (3k) displayed better antiproliferative activity with IC50 (50% inhibitory concentration) values of 5.90 ± 0.41 and 6.25 ± 0.37 µM toward HepG2 cells compared to cisplatin, while they exhibited lower cytotoxicity against HL-7702. Therefore, the 1,2,3-triazole-hybrids could be a promising strategy for the synthesis of antitumor diterpenoids and it also proved the essential role of 1,2,3-triazole moiety of DHAA in the biological activity.

[A new polyketide from marine-derived Streptomyces sp.MDW-06].

To isolate and identify secondary metabolites of marine-derived Streptomyces sp.MDW-06,the isolations and purifications of compounds were performed by means of column chromatography over silica gel. And their structures were elucidated through the spectroscopic analysis of MS,NMR and specific rotations. The bioactivities were assayed by paper diffusion and DPPH method. From the fermentation broth of marine-derived Streptomyces sp.MDW-06,five compounds( 1-5) were isolated and identified as streptopentanoic acid( 1),germicidin A( 2),germicidin B( 3),isogermicidin A( 4),isogermicidin B( 5) and oxohygrolidin( 6),respectively. Compound 1 is a new compound. Compound 1 shows DPPH radical scavenging activity with 36. 4% at 100 mg·L~(-1).

Synthesis and Biological Evaluation of Novel Dehydroabietic Acid-Oxazolidinone Hybrids for Antitumor Properties.

Novel representatives of the important group of biologically-active, dehydroabietic acid-bearing oxazolidinone moiety were synthesized to explore more efficacious and less toxic antitumor agents. Structures of all the newly target molecules were confirmed by IR, ¹H-NMR, 13C-NMR, and HR-MS. The inhibitory activities of these compounds against different human cancer cell lines (MGC-803, CNE-2, SK-OV-3, NCI-H460) and human normal liver cell line LO2 were evaluated and compared with the commercial anticancer drug cisplatin, using standard MTT (methyl thiazolytetrazolium) assay in vitro. The pharmacological screening results revealed that most of the hybrids showed significantly improved antiproliferative activities over dehydroabietic acid and that some displayed better inhibitory activities compared to cisplatin. In particular, compound 4j exhibited promising cytotoxicity with IC50 values ranging from 3.82 to 17.76 µM against all the test cell lines and displayed very weak cytotoxicity (IC50 > 100 µM) on normal cells, showing good selectivity between normal and malignant cells. Furthermore, the action mechanism of the representative compound 4j was preliminarily investigated by Annexin-V/PI dual staining, Hoechst 33258 staining, which indicated that the compound can induce cell apoptosis in MGC-803 cells in a dose-dependent manner and arrest the cell cycle in G1 phase. Therefore, 4j may be further exploited as a novel pharmacophore model for the development of anticancer agents.

Synthesis and Antifungal Activity of Novel Myrtenal-Based 4-Methyl-1,2,4-triazole-thioethers.

A series of novel myrtenal derivatives bearing 1,2,4-triazole moiety were designed and synthesized by multi-step reactions in an attempt to develop potent antifungal agents. Their structures were confirmed by using UV-vis, FTIR, NMR, and ESI-MS analysis. Antifungal activity of the target compounds was preliminarily evaluated by the in vitro method against Fusarium oxysporum f. sp. cucumerinum, Physalospora piricola, Alternaria solani, Cercospora arachidicola, and Gibberella zeae at 50 µg/mL. Compounds 6c (R = i-Pr), 6l (R = o-NO2 Bn), and 6a (R = Et) exhibited excellent antifungal activity against P. piricola with inhibition rates of 98.2%, 96.4%, and 90.7%, respectively, showing better or comparable antifungal activity than that of the commercial fungicide azoxystrobin with a 96.0% inhibition rate, which served as a positive control.

Synthesis and Biological Activity of Novel (Z)- and (E)-Verbenone Oxime Esters.

Twenty-seven (Z)- and (E)-verbenone derivatives bearing an oxime ester moiety were designed and synthesized in search of novel bioactive molecules. Their structures were confirmed by UV-Vis, FTIR, NMR, ESI-MS, and elemental analysis. The antifungal and herbicidal activities of the target compounds were preliminarily evaluated. As a result, compound (E)-4n (R = ß-pyridyl) exhibited excellent antifungal activity with growth inhibition percentages of 92.2%, 80.0% and 76.3% against Alternaria solani, Physalospora piricola, and Cercospora arachidicola at 50 µg/mL, showing comparable or better antifungal activity than the commercial fungicide chlorothalonil with growth inhibition of 96.1%, 75.0% and 73.3%, respectively, and 1.7-5.5-fold more growth inhibition than its stereoisomer (Z)-4n (R = ß-pyridyl) with inhibition rates of 22.6%, 28.6% and 43.7%, respectively. In addition, seven compounds displayed significant growth inhibition activity of over 90% against the root of rape (Brassica campestris) at 100 µg/mL, exhibiting much better herbicidal activity than the commercial herbicide flumioxazin with a 63.0% growth inhibition. Among these seven compounds, compound (E)-4n (R = ß-pyridyl) inhibited growth by 92.1%, which was 1.7-fold more than its stereoisomer (Z)-4n (R = ß-pyridyl) which inhibited growth by 54.0%.

Synthesis of magnetic molecularly imprinted polymers for the selective separation and determination of metronidazole in cosmetic samples.

In this study, novel magnetic molecularly imprinted polymers (MMIPs) were developed as a sorbent for solid-phase extraction (SPE) and used for the selective separation of metronidazole (MNZ) in cosmetics; MNZ was detected by high-performance liquid chromatography (HPLC). First, magnetic Fe3O4 nanoparticles (NPs) were prepared by the co-precipitation of Fe(2+)and Fe(3+) ions in an ammonia solution; then oleic acid (OA) was modified onto the surface of Fe3O4NPs. Finally, the MMIP was prepared by aqueous suspension polymerization, involving the copolymerization of Fe3O4NPs@OA with MNZ as the template molecule, methacrylic acid (MAA) as the functional monomer, ethylene glycol maleic rosinate acrylate (EGMRA) as the cross-linking agent, and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The MMIP materials showed high selective adsorption capacity and fast binding kinetics for MNZ; the maximum adsorption amount of the MMIP to MNZ was 46.7 mg/g. The assay showed a linear range from 0.1 to 20.0 µg/mL for MNZ with the correlation coefficient 0.999. The relative standard deviations (RSD) of intra- and inter-day ranging from 0.71 to 2.45% and from 1.06 to 5.20% were obtained. The MMIP can be applied to the enrichment and determination of MNZ in cosmetic products with the recoveries of spiked toner, powder, and cream cosmetic samples ranging from 90.6 to 104.2, 84.1 to 91.4, and 90.3 to 100.4%, respectively, and the RSD was <3.54%.

Separation of Panax notoginseng saponins on modified rosin ester-bonded silica stationary phase and its mechanism.

A column prepared using a unique three-membered phenanthrene skeleton of rosin has complementary selectivity to a C18 column for some separation tasks. In this study, propylene pimaric acid (16-hydroxyethyl acrylate-34-n-butyl) ester (BRB) and propylene pimaric acid (16-hydroxyethyl acrylate-34-dodecyl) ester (BRLA) were used as functional ligands to prepare two novel stationary phases, namely BRB@SiO2 and BRLA@SiO2, through a "thiol-ene" click chemistry reaction. The characterization results of Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption measurements, and contact angle tests showed that the BRB@SiO2 and BRLA@SiO2 stationary phases were successfully prepared. In addition, the performance of the columns was evaluated using the Tanaka test and hydrophobic subtraction model, which showed that the stationary phases exhibited typical reversed-phase chromatography performance and good hydrophobicity, hydrophobic selectivity, and steric selectivity. The changes in the retention of Panax notoginseng saponins on a column under different chromatographic conditions (acetonitrile content, flow rate, and column temperature) were investigated. The separation effect of BRB@SiO2 and BRLA@SiO2 columns on P. notoginseng saponins was better than that of the C18 column and the BRLA@SiO2 column could replace the C18 column for the detection of P. notoginseng saponins.

Design, Synthesis, and Molecular Docking Study of Novel 3-Cyanopyridine Derivatives for the Anti-Cancer Drug Target Survivin Protein.

Survivin is an important member of the antiapoptotic protein family and controls the cell's life cycle. Overexpression of survivin in tumor cells leads to inhibition of apoptosis, thus contributing to cancer cell proliferation. The largest binding pocket in the survivin dimer was located in the BIR domain. The key to the efficacy of 3-cyanopyridines was their surface interaction with the survivin amino acid Ile74. METHODS: Through the optimization of the 3-cyanopyridine, 29 new compounds with a 3- Cyanopyridine structure were designed, synthesized, and characterized by NMR, IR, and mass spectrometry. The antitumor activity of the compounds in vitro was detected by the MTT method. RESULTS: In vitro anti-tumor experiments showed that some compounds exhibited good anti-cancer effects. The IC50 values of the compound 2-amino-6-(2,4-difluorophenyl)-4-(4-hydroxyphenyl) nicotinonitrile (10n) against human liver cancer (Huh7), human glioma (U251), and human melanoma (A375) cells were 5.9, 6.0 and 7.2 µM, respectively. The IC50 values of the compound 6-(2,4-difluorophenyl)- 4-(4-hydroxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (9o) against Huh7, U251 and A375 cells were 2.4, 17.5 and 7.2 µM, respectively, which were better than those of 10- hydroxycamptothecin and 5-fluorouracil. Analysis of the results of molecular dynamics simulation established that the BIR domain is the optimal binding site on the survivin protein, and the fingerprints of the eight most active compounds and the molecular docking to the survivin protein are analyzed. CONCLUSION: 3-Cyanopyridine is an excellent backbone for antitumor lead compounds, 10n and 9o, as derivatives of 3-Cyanopyridine are excellent survivin protein-targeting inhibitors worthy of further study. The key factor in inhibiting survivin protein through the action of amino acid Ile74.

A 3-D metal-organic framework constructed with manganese(ΙΙ), 4,4'-oxybis(benzoic acid) and 2,2'-biphenyl: synthesis, crystal structure and photoelectric property characterization.

Assembly of 4,4'-oxybis(benzoic acid) (H(2)L) with manganese chloride in the presence of 2,2'-biphenyl (2,2'-bpy) affords a new coordination polymer [Mn(3)L(3)(2,2'-bpy)(2)](n) (1), in which the [MnL(2)]n layers are extended by L bridges resulting in a three-dimensional (3-D) coordination framework. The network structure of 1 has unusual (2,6)-connectivity and represents a new type of (8(12) · 12(3))(8)(3) topology. These identical and complementary networks are entangled to generate a self-penetrating supramolecular lattice. Moreover, the fluorescence spectrum of 1 exhibits fluorescent emission in the solution of methanol at room temperature. Electrochemical investigation illustrates the electrochemical properties of the title compound. The structure (C(62)H(40)Mn(3)N(4)O(15))(n) is monoclinic with a = 14.2304(18), b = 17.019(2), c = 25.805(3) Å, α = γ = 90, ß = 92.932(2)° and space group C2/c.

N-doped pinecone-based carbon with a hierarchical porous pie-like structure: a long-cycle-life anode material for potassium-ion batteries.

Pinecone-based biomass carbon (PC) is a potential anode material for potassium-ion batteries because it is abundant, cheap, renewable, and easy to obtain. However, because of inferior kinetics and the effects of volume expansion due to the large radius of the K+ ion, it does not meet commercial performance requirements. In this study, nitrogen-doped PC (NPC) was prepared by carbonization in molten ZnCl2 with urea as a nitrogen source. A strategy based on synergistic effects between N doping and ZnCl2 molten salt was used to produce a hierarchically porous pie-like NPC with abundant defects and active sites and an enlarged interlayer distance-properties that enhance K+ adsorption, promote K+ intercalation/diffusion, and reduce the effects of volume expansion. This NPC exhibited a high reversible capacity (283 mA h g-1 at 50 mA g-1) and superior rate performance and cyclic stability (110 mA h g-1 after 1000 cycles at 5 A g-1), demonstrating its potential for use in potassium-ion batteries.

Structural elucidation of high-molecular-weight alkaline degradation products of hexoses.

High-molecular-weight alkaline degradation products of hexoses (HMWHADPs) are colored substances in sugar solutions formed during sugar manufacturing process. These products may be occluded within sugar crystals and impart yellow or brown color to sucrose, thereby negatively affecting the quality of white sugar. Thus, the structural properties of HMWHADPs pose a significant scientific problem in the sugar industry. In the present study, the structural properties of HMWHADPs were investigated using nuclear magnetic resonance, zeta potential analyzer, energy-dispersive X-ray spectrometry, ultraviolet-visible spectra, and Fourier transform infrared spectroscopy. Results showed that HMWHADPs mainly contain carboxyl, aldehyde, alcoholic hydroxyl, conjugated double bonds, and saturated alkanes. Possible mechanisms of HMWHADP formation were proposed on the basis of structural property investigation. This study can be used as reference for future research and practice in developing effective methods for the removal of HMWHADPs from sugar solutions and prevention of their further formation in subsequent steps.

[Evaluation of Performance of an Aminated Rosin-based Resin for Adsorption of Norfloxacin from Aqueous Solutions].

An aminated rosin-based resin (ARBR) was synthesized as a novel environmentally-friendly adsorbent for removal of Norfloxacin (NOR) from aqueous solutions. Its features were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and surface area measurements (BET). The effects of resin dosage, pH, and ionic strength on the ARBR adsorption properties of NOR were investigated by batch experiments. Results showed that the NOR adsorption amounts increased with pH in the range from 2.0 to 6.0, but decreased at higher pH (8-10). The adsorption process of NOR followed a pseudo-second rate model and could be fitted to the Langmuir isotherm, with calculated maximum monolayer adsorption capacity of 30.29 mg·g-1 at pH 6.0 and 20℃. Thermodynamic calculations showed that the adsorption of NOR was a spontaneous and endothermic process and could be attributed to a combination of electrostatic interactions and hydrogen bonding. Furthermore, the adsorbed NOR on ARBR could be efficiently desorbed by 0.1 mol·L-1 HCl to regenerate the resin. After five adsorption-desorption recycles, ARBR had a stable adsorption performance and could be recycled. The adsorption performance is better than that of various commercial resins, and these research results contribute to the development of applications of rosin derivatives and their utilization in the environmental control of micro pollutants.

The first synthesis of Krempene B.

The synthesis of Krempene B, which can be isolated from the marine soft coral Cladiella krempfi, is achieved in 23.9% overall yield from commercially available 3ß-acetoxy-5-pregnen-20-one by 11 steps. Key transformations include the dienone-phenol rearrangement of steroids and Wittig reaction.