Efficient extraction and antioxidant activity of polyphenols from Antrodia cinnamomea.

BACKGROUND: Antrodia cinnamomea, a rare medicinal fungus, has been increasingly studied in recent years because of its abundant secondary metabolites which are beneficial to humans. However, there is a lack of research on its polyphenols which are of good research value due to their antioxidant, anti-inflammatory, hypoglycemic and other activities. RESULTS: In this study, the effects of different extraction conditions on the yield of its polyphenols were investigated. Deep-Eutectic Solvents composed of choline chloride and malonic acid had the best extraction efficiency, with the optimal extraction conditions being as follows: a solid-liquid ratio of 40 mg/mL, an extraction temperature of 55 °C, an extraction time of 70 min and a DES with 20% water content. Under these conditions, the extraction yield of polyphenols reached 22.09 mg/g which was about 2 times that of alcohol-based extraction (10.95 mg/g). In vitro antioxidant test results further showed that polyphenols from A. cinnamomea had strong antioxidant activities. When the concentration of polyphenols reached 0.1 mg/mL of polyphenols, the scavenging activity of free radical basically reached its maximum, with values of 94.10%, 83.34% and 95.42% for DPPH, ABTS+ and ·OH scavenging. In this case, the corresponding IC50 values were 0.01, 0.014 and 0.007 mg/mL, respectively. CONCLUSIONS: This study lays the foundation for the efficient extraction and application of polyphenols from A. cinnamomea.

Optimization of Extraction Process and the Antioxidant Activity of Phenolics from Sanghuangporus baumii.

Sanghuangporus baumii, is a widely used medicinal fungus. The polyphenols extracted from this fungus exert antioxidant, anti-inflammatory, and hypoglycemic effects. In this study, polyphenols from the fruiting bodies of S. baumii were obtained using the deep eutectic solvent (DES) extraction method. The factors affecting the extraction yield were investigated at different conditions. Based on the results from single-factor experiments, response surface methodology was used to optimize the extraction conditions. The scavenging ability of the polyphenols on •OH, DPPH, and ABTS+ was determined. The results showed that the DES system composed of choline chloride and malic acid had the best extraction yield (6.37 mg/g). The optimal extraction parameters for response surface methodology were as follows: 42 min, 58 ℃, 1:34 solid-liquid (mg/mL), and water content of 39%. Under these conditions, the yield of polyphenols was the highest (12.58 mg/g). At 0.30 mg/mL, the scavenging ability of the polyphenols on •OH, DPPH, and ABTS+ was 95.71%, 91.08%, and 85.52%, respectively. Thus, the method using DES was more effective than the conventional method of extracting phenolic compounds from the fruiting bodies of S. baumii. Moreover, the extracted polyphenols exhibited potent antioxidant activity.

An overview on natural farnesyltransferase inhibitors for efficient cancer therapy.

As one of the world's five terminally ills, tumours can cause important genetic dysfunction. However, some current medicines for tumours usually have strong toxic side effects and are prone to drug resistance. Studies have found that farnesyltransferase inhibitors (FTIs) extracted from natural materials have a good inhibiting ability on tumours with fewer side effects. This article describes several FTIs extracted from natural materials and clarifies the current research progress, which provides a new choice for the treatment of tumours.

One-pot synthesis of multi-functional and environmental friendly tannic acid polymer with Fe3+ and formaldehyde as double crosslinking agents for selective removal of cation pollutants.

A novel multi-functional and environmental friendly tannic acid polymer (Fe3+-TA-HCHO) with Fe3+ and formaldehyde as double crosslinking agents together with cysteine as heteroatom source was prepared by a one-pot hydrothermal method. Characterization with transmission electron microscope (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), and elemental analysis demonstrated that the Fe3+-TA-HCHO possessed uniform structure and particle size as well as plentiful functional groups. The resulted Fe3+-TA-HCHO material as a adsorbent to remove methylene blue, sunset yellow, Pb2+, Hg2+, and AsO33- from water. The results suggested that Fe3+-TA-HCHO polymer (pHpzc is 2.33) showed different adsorption properties for anionic pollutants (sunset yellow and AsO33-) and cationic pollutants (methylene blue, Pb2+, and Hg2+). The material exhibited remarkable selectivity for adsorption and separation of pollutants. The maximum adsorption capacities calculated from Langmuir model for methylene blue, Pb2+, and Hg2+ were 154.32, 819.67, and 699.30 mg g-1, respectively. This is the first time that tannic acid polymer is synthesized by double crosslinking method, which not only developed a promising adsorbent for selective removal of cation pollutants, but also opened up a new avenue for synthesis and application of tannic acid polymer.

[Simultaneous determination of four phthalate esters in water samples using ultrasound-assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography].

Ultrasound-assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography (UA-DLLME-HPLC) was developed for the determination of four typical phthalate esters (PAEs). The analyzed PAEs included dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and di-n-octyl phthalate (DnOP). The UA-DLLME parameters such as types/volumes of extraction/dispersion solvents, ultrasonic time, ionic strength and extraction time, were investigated. Enrichment factor (EF)was employed to evaluate the extraction efficiency. The conditions were finally chosen: CCl4 (40 microL)/ acetonitrile (1.0 mL) as extraction/dispersion solvents; 30 g/L NaCl; ultrasound/centrifugation of 5 min. Under the optimized extraction conditions, UA-DLLME exhibited strong enrichment ability for the four PAEs. The EFs for DMP, DEP, DBP and DnOP obtained were 71, 144, 169 and 159, respectively. The limits of detection were 3.78, 1.77, 3.07 and 3.30 microg/L for DMP, DEP, DBP and DnOP, respectively. The satisfactory recoveries for three water samples at three spiked levels ranged from 82.99%-114.47%, with the relative standard deviations of 1.93%-8.31%. It is a convenient, speedy, environmentally benign method for the routine analysis of PAEs in water samples.

[Positive regulation in expression of the phenazine-producing operon phz2 mediated by pip in Pseudomonas aeruginosa PAO1].

UNLABELLED: Pseudomonas aeruginosa PAO1, an opportunistic pathogenic bacterium, produces phenazine and its derivatives which play a critical role in pathogen-host interaction during its infection. In a biological control strain P. chlororaphis PCL1391, Pip positively regulates PCN production. OBJECTIVE: Our aim is to identify the function and regulation of an ORF of PA0243 (the homolog of Pip) in Pseudomonas aeruginosa PAO1. METHODS: We first cloned the fragment of the pip gene from the chromosomal DNA of P. aeruginosa PAO1 and constructed the pip-defect mutant PA-PG with the insertion of gentamycin resistance cassette (aacC1). With construction and introduction of pME10P (containing the whole pip gene region) , complementation of the pip was then carried out. With creation of the mutants PA-PD-Z1G and PA-PG-Z2K, phenazine-1-carboxylic acid and pyocyanin were measured in GA medium in relative mutants, respectively. RESULTS: In GA medium, production of phenazine-1-carboxylic acid and pyocyanin in the mutant PA-PG decreased dramatically in comparison with that produced in the wild type strain PAO1. The amounts of phenazine-1-carboxylic acid and pyocyanin, however, were recovered with complementation of the derivative PA-PG bearing pME10P. The production of phenazine-1-carboxylic acid and pyocyanin in mutant PA-PG-Z2K were same to those in parental strain PA-Z2K. Phenazine-1-carboxylic acid and pyocyanin produced by the mutant PA-PD-Z1G were lower than those in the original strain PA-Z1G. CONCLUSION: With these results, it is suggested that Pip exerts positively regulation in phenazine biosynthesis by specifically modulating expression of the phz2 operon, not by mediating expression of the phzl operon in P. aeruginosa PAO1.

[Fast determination of andrographolide and dehydroandrographolide in Xiaoyanlidan Tablets by microemulsion electrokinetic chromatography].

A microemulsion electrokinetic chromatography (MEEKC) method for the determination of andrographolide and dehydroandrographolide in Xiaoyanlidan Tablets was established. The MEEKC method involved the use of sodium dodecyl sulfate (SDS) as surfactant, ethyl acetate as organic solvent and 1-butanol as co-surfactant. The effects of several factors such as the acidity and concentration of borate buffer, SDS and 1-butanol contents were investigated. The optimized composition (by mass) of microemulsion system are 0.5% ethyl acetate--0.6% SDS--6.0% 1-butanol--92.9% 30 mmol/L sodium tetraborate buffer (pH 9.5). This system allowed a useful and reproducible separation of the analytes to be achieved in less than 6 min. The proposed method is a simple, fast and sensitive method for the determination of andrographolide and dehydroandrographolide in Xiaoyanlidan Tablets.

[Chiral separation of dipeptides by capillary electrophoresis].

Peptides are increasingly used as pharmaceutical agents. Many small peptides are the essential compounds in biological systems. Direct chiral separation of dipeptide derivatives using 9-(2-carbazole) ethyl chloroformate (CEOC) as the derivatizing agent by capillary electrophoresis (CE) with beta-cyclodextrin (beta-CD) and sodium deoxycholate (SDC) as chiral selectors has been developed. It has been well recognized that the combination of the binary selectors can enhance the selectivity and resolution instead of either beta-CD or SDC alone. The molar ratio of the binary chiral selectors, the buffer concentration and pH of Tris-H3PO4, organic modifier were studied and optimized. Complete chiral separations for 14 dipeptide derivatives using beta-CD and SDC as binary chiral selectors were obtained. The results indicated that each pair of D/L chiral resolution was more than 3.63, and the highest resolution for Gly-Ala was 43.14.

Rapid separation and determination of resibufogenin and cinobufagin in toad venom and Liushen tablet by beta-cyclodextrin modified micellar electrokinetic chromatography.

A rapid cyclodextrin modified micellar electrokinetic chromatography (CD-MEKC) method was proposed for the determination of resibufogenin and cinobufagin in the Chinese herbal extracts from toad venom and its medicinal preparation (Liushen tablet). The two components have the close structural similarity and similar hydrophobicity, which result in poor resolution in normal MEKC. The addition of neutral beta-CD to the MEKC system was found to improve the separation of the studied compounds. The effects of several CD-MEKC parameters on the resolutions were evaluated systematically. Based on the investigation, a background electrolyte solution consisting of 10 mM borate buffer adjusted to pH 8.5, 40 mM sodium dodecyl sulfate (SDS), 12 mM beta-CD and 10% (v/v) of methanol was found to be optimal conditions for the fast separation. The contents of resibufogenin and cinobufagin were successfully determined within 5 min, with satisfactory repeatability and recovery.

Development of a sensitive fluorescent derivatization reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) and its application for determination of amino acids from seeds and bryophyte plants using high-performance liquid chromatography with fluorescence detection and identification with electrospray ionization mass spectrometry.

A pre-column derivatization method for the sensitive determination of amino acids and peptides using the tagging reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives was carried out by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS/MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent was replaced by 1,2-benzo-3,4-dihydrocarbazole functional group, which resulted in a sensitive fluorescence derivatizing reagent BCEOC. BCEOC can easily and quickly label peptides and amino acids. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography. The derivatives showed an intense protonated molecular ion corresponding m/z (M+H)(+) under electrospray ionization (ESI) positive-ion mode with an exception being Tyr detected at negative mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 246.2 corresponding to the cleavage of CO bond of BCEOC molecule. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3-4-fold molar reagent excess. Derivatives exhibit strong fluorescence and extracted derivatization solution with n-hexane/ethyl acetate (10:1, v/v) allows for the direct injection with no significant interference from the major fluorescent reagent degradation by-products, such as 1,2-benzo-3,4-dihydrocarbazole-9-ethanol (BDC-OH) (a major by-product), mono-1,2-benzo-3,4-dihydrocarbazole-9-ethyl carbonate (BCEOC-OH) and bis-(1,2-benzo-3,4-dihydrocarbazole-9-ethyl) carbonate (BCEOC)(2). In addition, the detection responses for BCEOC derivatives are compared to those obtained with previously synthesized 2-(9-carbazole)-ethyl chloroformate (CEOC) in our laboratory. The ratios AC(BCEOC)/AC(CEOC)=2.05-6.51 for fluorescence responses are observed (here, AC is relative fluorescence response). Separation of the derivatized peptides and amino acids had been optimized on Hypersil BDS C(18) column. Detection limits were calculated from 1.0pmol injection at a signal-to-noise ratio of 3, and were 6.3 (Lys)-177.6 (His) fmol. The mean interday accuracy ranged from 92 to 106% for fluorescence detection with mean %CV<7.5. The mean interday precision for all standards was <10% of the expected concentration. Excellent linear responses were observed with coefficients of >0.9999. Good compositional data could be obtained from the analysis of derivatized protein hydrolysates containing as little as 50.5ng of sample. Therefore, the facile BCEOC derivatization coupled with mass spectrometry allowed the development of a highly sensitive and specific method for the quantitative analysis of trace levels of amino acids and peptides from biological and natural environmental samples.