Novel Protein Tyrosine Phosphatase 1B Inhibitor-Geranylated Flavonoid from Mulberry Leaves Ameliorates Insulin Resistance.

Mulberry leaf is a common vegetable with a variety of beneficial effects, such as hypoglycemic activity. However, the underlying mechanism of its hypoglycemic effect have not been fully revealed. In this study, two flavonoid derivatives were isolated from mulberry leaves, a new geranylated flavonoid compound (1) and its structural analogue (2). The structures of compounds 1 and 2 were elucidated using spectroscopic analysis. To study the potential hypoglycemic properties of these compounds, their regulatory effects on protein tyrosine phosphatase 1B (PTP1B) were investigated. In comparison to oleanolic acid, compounds 1 and 2 showed significant inhibitory activities (IC50 = 4.53 ± 0.31 and 10.53 ± 1.76 µM) against PTP1B, the positive control (IC50 = 7.94 ± 0.76 µM). Molecular docking predicted the binding sites of compound 1 to PTP1B. In insulin-resistance HepG2 cell, compound 1 promoted glucose consumption in a dose-dependent manner. Furthermore, western blot and polymerase chain reaction analyses indicated that compound 1 might regulate glucose consumption through the PTP1B/IRS/PI3K/AKT pathway. In conclusion, geranylated flavonoids in mulberry leaves inhibite PTP1B and increase the glucose consumption in insulin-resistant cells. These findings provide an important basis for the use of mulberry leaf flavonoids as a dietary supplement to regulate glucose metabolism.

In vitro Antibiotic Susceptibility, Virulence Genes Distribution and Biofilm Production of Staphylococcus aureus Isolates from Bovine Mastitis in the Liaoning Province of China.

PURPOSE: The aim of this study was to identify the subtype, characterize the antimicrobial resistance, determine the virulence gene distribution, and analyze the biofilm production of Staphylococcus aureus isolates from bovine mastitis milk samples in the Liaoning Province of China. MATERIALS AND METHODS: In total, 56 Staph. aureus isolates were collected and identified in this study; the isolates were divided into different spa types based on the sequence of the polymorphic X region of the spa gene. Additionally, antimicrobial susceptibility was investigated using the broth microdilution method, and 18 virulence genes were detected using PCR. Biofilm formation was measured by spectrophotometry with crystal violet staining and observed using confocal laser scanning microscopy. RESULTS: There were 12.12% (56/462) milk samples that were positive for Staph. aureus. These isolates were nonsusceptible to sulfamethoxazole (100%), penicillin (76.9%), daptomycin (76.79%), clindamycin (69.64%), and oxacillin (60.71%); however, the majority of the isolates (80.4%) were susceptible to amoxicillin/clavulanate. The predominant virulence genes encoded the cytotoxins, hla (94.64%) and hlb (89.29%), and the adhesion factors clfA (89.29%), clfB (89.29%), and fnbB (80.36%). Comparatively, virulence genes related to other adhesion factors such as cna (8.93%) and enterotoxins, such as seg (26.79%), sea (16.07%), seb (7.14%), and sec (7.14%) were detected at relatively lower rates. The following eight spa types were identified: t267 (35.84%), t730 (22.64%), t518 (15.09%), t1190 (11.32%), t1456 (9.43%), t224 (1.88%), t9129 (1.88%), and t177 (1.88%). The highest biofilm production was observed for t267. Staph. aureus exhibited various patterns of biofilm formation, with the biofilm often being associated with a tower-shaped structure or a thicker biofilm. CONCLUSION: Our results indicated that Staph. aureus isolates from dairy cows with mastitis in the Liaoning Province of China were non-susceptible to sulfamethoxazole, penicillin, daptomycin, oxacillin, and clindamycin. Additionally, the most prevalent subtype was t267, which displayed resistance to multiple antimicrobial agents and harbored several virulence genes, including clfA, clfB, fnbB, hla, and hlb.

Resistance to ß-lactam antibiotic may influence nanH gene expression in Trueperella pyogenes isolated from bovine endometritis.

Virulence could be modulated by many instinctive and environmental factors including oxygen, osmolarity and antimicrobial agents. This study aimed to investigate the correlation between drug resistance and the nanH expression in Trueperella pyogenes (T. pyogenes). Minimum inhibitory concentrations (MICs) of 6 ß-lactam antimicrobial agents (penicillin G, amoxicillin, oxacillin, cefazolin, ceftiofur, and ampicillin) against T. pyogenes were tested by standard broth dilution method according to the protocols of the Clinical and Laboratory Standards Institute (CLSI), and real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR) was selected to investigate the mRNA expression levels of the nanH in T. pyogenes. All the isolates were resistant to atleast 2 of antimicrobial agents, and multidrug resistance (resistance to atleast 3 antimicrobials) was observed in 84.38% (27/32) of isolates. The mRNA expression levels of the nanH were significantly higher in comparison with that in ATCC19411, as the resistance profile enlarged, the nanH mRNA expression levels decreased in T. pyogenes. These results indicated that ß-lactam antibiotic resistance in T. pyogenes may alter the expression of the nanH.

3-(3,4-Dimeth-oxy-phen-yl)-4-(2-meth-oxy-anilino)furan-2(5H)-one.

In the title compound, C(19)H(19)NO(5), the furan-one unit makes a dihedral angle of 30.93 (6)° with the benzene ring and a dihedral angle of 9.51 (6)° with the aniline ring. In the crystal, inter-molecular C-H⋯O hydrogen bonds and C-H⋯π contacts link the mol-ecules into sheets. A weak intramolecular hydrogen bond is also observed.

[Extract berberine hydrochloride by aqueous two-phase system].

OBJECTIVE: To study the aqueous two-phase system which could be used for extraction of berberine hydrochloride. METHODS: Three aqueous two-phase systems were used for extraction experiment firstly, the best one was chosen from that, and then the single factor experiment and orthogonal experiment were carried out. RESULTS: 10 mL 95% ethanol with 10 mL 2.2 mol/L ammonium sulfate could make a aqueous two-phase system, added 600 mg berberine hydrochloride whose purity was 53.22% into it, regulated its pH to 4, then the system was put into water-bath heater (70 degrees C) for 30 min, the extraction rate could reach 99.29%; Collected the extraction liquid, dried it under 40 degrees C, the purity of berberine hydrochloride was 88.43%. CONCLUSION: This system is a suitable aqueous two-phase system for extraction of berberine hydrochloride.

(Z)-2-Acetamido-3-(4-chloro-phen-yl)acrylic acid.

In the title compound, C(11)H(10)ClNO(3), the mol-ecule consists of a benzene ring and an acetamido-acrylic acid unit on opposite sides of the C=C double bond. In the crystal, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds assemble the mol-ecules into infinite two-dimensional ribbons. These ribbons are linked into a network by inter-molecular C-H⋯π contacts.

(Z)-2-Hydr-oxy-3-(4-methoxy-phen-yl)acrylic acid.

In the structure of the title compound, C(10)H(10)O(4), inversion dimers linked by pairs of O-H⋯O hydrogen bonds link the carboxylic acid groups. Further O-H⋯O links cross-link the dimers into sheets running along the b-axis direction.