Dendrimer-Based Demulsifiers for Polymer Flooding Oil-in-Water Emulsions

Two polyamidoamine-based dendritic molecules, named here as benzyl-G3 and octyl-G3, were synthesized using H₂NCH₂CH₂NRCH₂CH₂NH₂ (where R is either rigid benzyl or flexible octyl hydrophobic tails that are linked to the central nitrogen atom). With consideration of factors, such as the settling time, demulsifier dosage, temperature, oil content, and kinds of surfactants, the synthesized molecules were systematically investigated as demulsifiers for breaking up polymer flooding oil-in-water emulsions. In comparison to traditional G3 polyamidoamine, both benzyl-G3 and octyl-G3 exhibited better demulsification efficiencies with a dosage of 200 mg/L at a relatively low temperature (30 °C) in short periods of time (40 min) and reached 99.3 and 99.8% oil removal rates as they were added to the low oil-containing emulsion (1500 mg/L), respectively. A series of measurement methods were then adopted to explore the demulsification mechanism of the two demulsifiers. The interfacial tension and ζ potential measurements indicated that the high demulsification efficiency of the two dendrimers could be due to electrostatic charge neutralization. Moreover, the dendrimers and surfactants showed strong interactions according to the turbidity measurements, the results of which demonstrated that the hydrophobic tails located at the center of the dendrimers also influenced the demulsification efficiency

An Enzyme-Responsive Nanogel Carrier Based on PAMAM Dendrimers for Drug Delivery

G4 PAMAM dendrimer molecules were modified via covalently conjugating RGDC, RAADyC, and PEG chains on the periphery (<b>Mac-1</b>), by which a nanogel drug carrier with enzyme-sensitivity (<b>NG-1</b>) was constructed through an oxidation reaction by using NaIO₄ to initiate the chemical cross-link of the functional groups on the periphery of dendrimers. <b>Mac-1</b> and <b>NG-1</b> both had a spherelike shape with a relatively uniform size of 20 nm for <b>Mac-1</b> and 50 nm for <b>NG-1</b> as evidenced by TEM, SEM, and DLS measurements. <b>NG-1</b> showed much higher drug loading capacity as compared with that of <b>Mac-1</b> although the cavities in the dendritic structure were used to encapsulate drug molecules as reported in many literatures. In addition, the size of <b>NG-1</b> with embedded doxorubicin hydrochloride (DOX) decreased significantly to 15 nm in the presence of elastase, which indicated the decomposition of the nanogel triggered by enzyme, leading to drug release in a sustained manner <i>in vitro</i>. The <b>NG-1</b> carrier was noncytotoxic and biocompatible, and it achieved the same cytotoxicity as free DOX when the drug molecules were loaded inside. From confocal images, the penetrative process of DOX from nanogel could be clearly observed in 8 h. Such a dendrimer-based nanogel may be a potential nanocarrier for drug delivery in cancer therapy

Molecular Size, Shape, and Electric Charges: Essential for Perylene Bisimide-Based DNA Intercalator to Localize in Cell Nuclei and Inhibit Cancer Cell Growth

The molecular properties concerning size, shape, and electric charges of the planar aromatic DNA intercalators are still poorly understood. Herein, a series of water-soluble perylene bisimide (PBI) derivatives containing a rigid and planar aromatic nanoscaffold with different size, shape, and electric charges were synthesized. Using histochemistry and cell viability assays on animal tissues and cancer cells, we revealed the molecular properties required for successful DNA intercalators to localize in cell nuclei and inhibit cancer cells. Small molecular size and the strong polarity of hydrophilic substituents are prerequisites for PBI-based DNA intercalators. A large number of charges facilitate the nucleic accumulation of these DNA intercalators, while fewer charges and planar aromatic nanoscaffold more efficiently inhibit cancer cell growth

Sacculatane Diterpenoids from the Liverwort Plagiochila nitens Collected in China

Seven new terpenoids, including six sacculatane diterpenoids plagiochilarins A–F (1–6), and one ent-2,3-seco-aromandrane sesquiterpenoid plagiochilarin H (8) with a 6/7/3/5 tetracyclic scaffold, alongside three known compounds, were obtained from the Chinese liverwort Plagiochila nitens Inoue. Plagiochilarin B (2) was unpredictably converted to the more stable artifact 7 under acid catalysis through cyclic ether formation. The reaction mechanism was reasonably deduced and experimentally verified. The structures of these terpenoids were determined by analysis of MS and NMR spectroscopic data and single-crystal X-ray diffraction. The inhibitory effect of all of the isolates was evaluated on the growth of two C. albicans strains, wild strain SC5314 and efflux pump-deficient strain DSY654. However, only plagiochilarin H (8) showed a MIC value of 16 μg/mL against C. albicans DSY654

Sacculatane Diterpenoids from the Liverwort Plagiochila nitens Collected in China

Seven new terpenoids, including six sacculatane diterpenoids plagiochilarins A–F (1–6), and one ent-2,3-seco-aromandrane sesquiterpenoid plagiochilarin H (8) with a 6/7/3/5 tetracyclic scaffold, alongside three known compounds, were obtained from the Chinese liverwort Plagiochila nitens Inoue. Plagiochilarin B (2) was unpredictably converted to the more stable artifact 7 under acid catalysis through cyclic ether formation. The reaction mechanism was reasonably deduced and experimentally verified. The structures of these terpenoids were determined by analysis of MS and NMR spectroscopic data and single-crystal X-ray diffraction. The inhibitory effect of all of the isolates was evaluated on the growth of two C. albicans strains, wild strain SC5314 and efflux pump-deficient strain DSY654. However, only plagiochilarin H (8) showed a MIC value of 16 μg/mL against C. albicans DSY654

Sacculatane Diterpenoids from the Liverwort Plagiochila nitens Collected in China

Seven new terpenoids, including six sacculatane diterpenoids plagiochilarins A–F (1–6), and one ent-2,3-seco-aromandrane sesquiterpenoid plagiochilarin H (8) with a 6/7/3/5 tetracyclic scaffold, alongside three known compounds, were obtained from the Chinese liverwort Plagiochila nitens Inoue. Plagiochilarin B (2) was unpredictably converted to the more stable artifact 7 under acid catalysis through cyclic ether formation. The reaction mechanism was reasonably deduced and experimentally verified. The structures of these terpenoids were determined by analysis of MS and NMR spectroscopic data and single-crystal X-ray diffraction. The inhibitory effect of all of the isolates was evaluated on the growth of two C. albicans strains, wild strain SC5314 and efflux pump-deficient strain DSY654. However, only plagiochilarin H (8) showed a MIC value of 16 μg/mL against C. albicans DSY654

Sacculatane Diterpenoids from the Liverwort Plagiochila nitens Collected in China

Seven new terpenoids, including six sacculatane diterpenoids plagiochilarins A–F (1–6), and one ent-2,3-seco-aromandrane sesquiterpenoid plagiochilarin H (8) with a 6/7/3/5 tetracyclic scaffold, alongside three known compounds, were obtained from the Chinese liverwort Plagiochila nitens Inoue. Plagiochilarin B (2) was unpredictably converted to the more stable artifact 7 under acid catalysis through cyclic ether formation. The reaction mechanism was reasonably deduced and experimentally verified. The structures of these terpenoids were determined by analysis of MS and NMR spectroscopic data and single-crystal X-ray diffraction. The inhibitory effect of all of the isolates was evaluated on the growth of two C. albicans strains, wild strain SC5314 and efflux pump-deficient strain DSY654. However, only plagiochilarin H (8) showed a MIC value of 16 μg/mL against C. albicans DSY654

Copy number variations of <i>LRRFIP1</i> gene and the relationship with growth traits in four Chinese sheep

CNVs (copy number variations) are the novel and common structural variants that could cover entire genes found in plenty of species. CNV may influence economically important traits or disease susceptibility in livestock species. Based on the whole genome resequencing results, we found that there was a CNV region on the LRRFIP1 gene. Then we used qPCR to detect the copy number type distribution in 553 individuals of four sheep breeds and used them for association analysis. The results showed that: (1) In the CKS, the sheep with gain type had a larger heart girth (p = 0.049). (2) For the HS, the CNV could significantly affect rump breadth (p = 0.037) and circumference of the cannon (p = 0.035). And the sheep with median type showed better performance in rump breadth and circumference of cannon. (3) At the STHS, the CNV was significantly correlated with chest width (p = 0.000) with loss type as the most favorable CNV type. Meanwhile, the best was the loss type, and the lowest was the median. (4) This CNV had no significant effect on the LTHS. So, the CNV of LRRFIP1 was related to the growth traits of these three sheep breeds and it may be used as a molecular marker for sheep.</p

Sacculatane Diterpenoids from the Liverwort Plagiochila nitens Collected in China

Seven new terpenoids, including six sacculatane diterpenoids plagiochilarins A–F (1–6), and one ent-2,3-seco-aromandrane sesquiterpenoid plagiochilarin H (8) with a 6/7/3/5 tetracyclic scaffold, alongside three known compounds, were obtained from the Chinese liverwort Plagiochila nitens Inoue. Plagiochilarin B (2) was unpredictably converted to the more stable artifact 7 under acid catalysis through cyclic ether formation. The reaction mechanism was reasonably deduced and experimentally verified. The structures of these terpenoids were determined by analysis of MS and NMR spectroscopic data and single-crystal X-ray diffraction. The inhibitory effect of all of the isolates was evaluated on the growth of two C. albicans strains, wild strain SC5314 and efflux pump-deficient strain DSY654. However, only plagiochilarin H (8) showed a MIC value of 16 μg/mL against C. albicans DSY654