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1.
Vivekananda Mandal Saikat Dewanjee Subhash C. Mandal 《Phytochemical analysis : PCA》2009,20(6):491-497
Objective – To develop a fast and ecofriendly microwave assisted extraction (MAE) technique for the effective and exhaustive extraction of gymnemagenin as an indicative biomarker for the quality control of Gymnema sylvestre. Methodology – Several extraction parameters such as microwave power, extraction time, solvent composition, pre‐leaching time, loading ratio and extraction cycle were studied for the determination of the optimum extraction condition. Scanning electron micrographs were obtained to elucidate the mechanism of extraction Results – The final optimum extraction conditions as obtained from the study were: 40% microwave power, 6 min irradiation time, 85% v/v methanol as the extraction solvent, 15 min pre‐leaching time and 25 : 1 (mL/g) as the solvent‐to‐material loading ratio. The proposed extraction technique produced a maximum yield of 4.3% w/w gymnemagenin in 6 min which was 1.3, 2.5 and 1.95 times more efficient than 6 h of heat reflux, 24 h of maceration and stirring extraction, respectively. A synergistic heat and mass transfer theory was also proposed to support the extraction mechanism Conclusion – Comparison with conventional extraction methods revealed that MAE could save considerable amounts of time and energy, whilst the reduction of volume of organic solvent consumed provides an ecofriendly feature. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
2.
Giuseppe Strazzullo Agata Gambacorta Filomena Monica Vella Barbara Immirzi Ida Romano Valeria Calandrelli Barbara Nicolaus Licia Lama 《World journal of microbiology & biotechnology》2008,24(8):1513-1519
In this study we suggest a simplified and effective method to directly recover polyhydroxyalkanoates (PHAs) from humid biomass
of Halomonas campaniensis with no pre-treatment steps. Sodium dodecyl sulphate (SDS) was directly added to dispersed biomass of cultured micro-organism
(w/w ratio: 1) in distilled water followed by shaking, heat treatment, and washing steps. The purity of the recovered PHAs
synthesized by H. campaniensis was over 95%, regardless of the cell concentrations and the best yield was 12% (w/w) of the cell wet weight when the micro-organism
was cultivated in a glucose-based medium or a glucose/propionate-based medium. MS spectroscopy and 1H, 13C-NMR analysis were used to chemically characterize the PHAs; their thermal characteristics were obtained using a differential
scanning calorimeter and the average viscosity molecular weight was assessed through specific viscosity measurements. Due
to its ease and velocity, our simplified method is suitable for the detection and recovery of PHAs from humid biomasses with
high yield and purity. The method, which is quick and at low environmental impact, is very valuable for the simultaneous testing
of cultures grown with different inducers for PHAs having particular chemical/physical characteristics. 相似文献
3.
Won-Kyo Kim Hee-Jeong Chae Jin-Hyun Kim 《Biotechnology and Bioprocess Engineering》2010,15(3):481-487
An efficient method using microwave energy was developed to extract homoharringtonine (HHT), an alkaloid component effective
in the treatment of leukemia, from Cephalotaxus koreana. The effects of major process parameters on extraction efficiency were also investigated. Using a fixed biomass-to-methanol
ratio of 1:8 (w/v), an extraction temperature of 30°C, an extraction time of 20 min, and a stirrer velocity of 250 rpm, a
25% higher yield of HHT was achieved using microwave-assisted extraction (MAE) than using conventional solvent extraction.
It was possible to recover more than 95% of the HHT by extracting twice using MAE. In addition, the HHT yield increased as
the extraction temperature increased, but the content of plant-derived tar and waxy compounds increased as well. Removal of
these impurities and of the pigments from extracts was most effectively accomplished at a mixing ratio of biomass-to-sylopute
of 1:1.5 (w/w). The effects of using different organic solvents (acetone, chloroform, ethanol, or methanol) for MAE were also
assessed; the highest extraction efficiency was obtained using methanol. When the agitation speed was altered, most of the
HHT (> 99%) was recovered at 250 rpm. A mixing ratio of biomass-to-methanol of 1:6 (w/v) at an extraction temperature of 40°C
and an extraction time of 10 min proved to be the most effective for reducing processing time and organic solvent usage while
enabling nearly all of the HHT (> 99%) to be recovered. 相似文献
4.
Minkova K Tchorbadjieva M Tchernov A Stojanova M Gigova L Busheva M 《Biotechnology letters》2007,29(4):647-651
A rapid, inexpensive and reliable procedure for separation and purification of C-phycocyanin (C-PC) and allophycocyanin (APC)
from Arthronema africanum based on a previously described rivanol-sulfate method for C-PC purification was developed. Exclusion of NaCl from the extraction
buffer resulted in complete separation of APC and C-PC, two-fold reduction of rivanol treatments, and a higher yield and purity
of C-PC. Pure C-PC (A620/A280 of 4.52) and APC (A652/A280 of 2.41) were obtained. The estimated molecular masses of the α and β subunits were 17 and 19 kDа for С-phycocyanin and 16
and 18 kDа for APC, respectively. The overall C-PC recovery of 55% (w/w) from its content (100 mg) in the crude extract was
10–20% higher than so far reported. The procedure appears promising for scaling up and broader applications. 相似文献
5.
Continuous cultures of two strains of Clostridium acetobutylicum were stable for over 70 d when grown on glucose/glycerol mixtures. Butanol was the major fermentation end-product, accounting for 43 to 62% (w/w) of total products. Low-grade glycerol [65% (w/v) purity] could replace commercial glycerol [87% (w/v) purity], leading to a similar fermentation pattern: a butanol yield of 0.34 (mol/mol), a butanol productivity of 0.42 g l–1 h–1 and a 84% (w/w) glycerol consumption were attained when cultures were grown at pH 6 and D = 0.05 h–1; butanol accounted for 94% (w/w) of total solvents. These values are among the highest reported in literature for C. acetobutylicum simple chemostats. 相似文献
6.
Rapid and selective extraction of phycocyanin from Spirulina platensis with ultrasonic cell disruption 总被引:1,自引:0,他引:1
Takao Furuki Shuichi Maeda Satoshi Imajo Tetsuya Hiroi Tsutomu Amaya Takahiko Hirokawa Kazuo Ito Hiroko Nozawa 《Journal of applied phycology》2003,15(4):319-324
A study was conducted on the efficiency of phycocyanin extraction from Spirulina platensis (Arthrospira platensis) cells disrupted by ultrasonic irradiation. Extraction followed first-order kinetics with respect to the length of time for irradiation. The first-order rate constant increased linearly with the output of ultrasonic irradiation. In order to extract phycocyanin there was an appropriate range of ultrasonic frequency, fu. In addition the most important finding is that the purity of phycocyanin in its crude extract depended on fu. For example, phycocyanin was extracted with higher purity at fu = 28 kHz than at fu = 20 kHz. It is suggested that rapid and selective extraction of phycocyanin from S. platensis may be possible if an optimized ultrasonic application is developed for a given suspension. 相似文献
7.
Microbial leaching of lateritic nickel ore 总被引:1,自引:1,他引:0
L. B. Sukla V. V. Panchanadikar R. N. Kar 《World journal of microbiology & biotechnology》1993,9(2):255-257
Lateritic nickel ore from the Sukinda Mines, Orissa, India, was leached using Thiobacillus ferrooxidans, Bacillus circulans, Bacillus licheniformis and Aspergillus niger at 5% (w/v) solid: liquid ratio for 5–20 days. Maximum leaching of Ni was achieved with B. circulans (85%) and Aspergillus niger (92%) after 20 days. Bacillus circulans showed significantly higher rate of leaching than the other organisms giving 80% Ni extraction after 15 days. The importance and usefulness of heterotrophic organisms in metal extraction are discussed. 相似文献
8.
Zhu Y Chen XB Wang KB Li YX Bai KZ Kuang TY Ji HB 《Applied microbiology and biotechnology》2007,74(1):244-248
C-phycocyanin (C-PC) was extracted from fresh Spirulina platensis by deploying a species of non-pathogenic nitrogen-fixing bacteria, namely, Klebsiella pneumoniae. The algal slurry was neither washed nor centrifuged; the bacterial culture was poured into the slurry, the vessel sealed,
and crude C-PC extracted after about 24 h. The extraction was clean and efficient, and the purity and concentration of C-PC
proved to be of adequate quality. 相似文献
9.
Alexander Staab Steffen Scheithauer Hiltrud Fieger-Büschges Ernst Mutschler Henning Blume 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2001,751(2)
An isocratic reversed-phase high-performance liquid chromatographic method for the simultaneous determination of denaverine and its N-monodemethyl metabolite (MD 6) in human plasma is described. The assay involves the extraction with an n-heptane–2-propanol mixture (9:1, v/v) followed by back extraction into 12.5% (w/w) phosphoric acid. The analytes of interest and the internal standard were separated on a Superspher RP8 column using a mobile phase of acetonitrile–0.12 M NH4H2PO4–tetrahydrofuran (24:17.2:1, v/v), adjusted to pH 3 with 85% (w/w) phosphoric acid. Ultraviolet detection was used at an operational wavelength of 220 nm. The retention times of MD 6, denaverine and the internal standard were 5.1, 6.3 and 10.2 min, respectively. The assay was validated according to international requirements and was found to be specific, accurate and precise with a linear range of 2.5–150 ng/ml for denaverine and MD 6. Extraction recoveries for denaverine and MD 6 ranged from 44 to 49% and from 42 to 47%, respectively. The stability of denaverine and MD 6 in plasma was demonstrated after 24 h storage at room temperature, after three freeze–thaw cycles and after 7 months frozen storage below −20°C. The stability of processed samples in the autosampler at room temperature was confirmed after 24 h storage. The analytical method has been applied to analyses of plasma samples from a pharmacokinetic study in man. 相似文献
10.
Fang L Liu Y Zhuang H Liu W Wang X Huang L 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(28):3023-3027
A microwave-assisted extraction (MAE) method is presented for the extraction of xanthones, α-mangostin and γ-mangostin from Garcinia mangostana. The MAE conditions including extraction temperature, liquid/solid ratio, extraction time and concentration of ethanol were optimized with an orthogonal test, and 5 g sample was extracted with the optimized conditions. The crude extraction of MAE was successfully isolated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (0.8:0.8:1:0.6, v/v) in one-step separation. The separation yielded 75 mg of α-mangostin at 98.5% purity, and 16 mg of γ-mangostin at 98.1% purity from 360 mg crude extract of G. mangostana in less than 7h. The purity of the two xanthones was determined by HPLC. Their structures were further identified by ESI-MS, (1)H NMR and (13)C NMR. 相似文献
11.
Eliane M.Z. Michielin Ana A. Salvador Carlos A.S. Riehl Artur Smnia Jr. Elza F.A. Smnia Sandra R.S. Ferreira 《Bioresource technology》2009,100(24):6615-6623
The present study describes the chemical composition and the antibacterial activity of extracts from Cordia verbenacea DC (Borraginaceae), a traditional medicinal plant that grows widely along the southeastern coast of Brazil. The extracts were obtained using different extraction techniques: high-pressure operations and low-pressure methods. The high-pressure technique was applied to obtain C. verbenacea extracts using pure CO2 and CO2 with co-solvent at pressures up to 30 MPa and temperatures of 30, 40 and 50 °C. Organic solvents such as n-hexane, ethyl acetate, ethanol, acetone and dichloromethane were used to obtain extracts by low-pressure processes. The antibacterial activity of the extracts was also subjected to screening against four strains of bacteria using the agar dilution method. The extraction yields were up to 5.0% w/w and up to 8.6% w/w for supercritical fluid extraction with pure CO2 and with ethyl acetate as co-solvent, respectively, while the low-pressure extraction indicates yields up to 24.0% w/w in the soxhlet extraction using water and aqueous mixture with 50% ethanol as solvents. The inhibitory activity of the extracts in Gram-positive bacteria was significantly higher than in Gram-negative. The quantification and the identification of the extracts recovered were accomplished using GC/MS analysis. The most important components identified in the extract were artemetin, β-sitosterol, α-humulene and β-caryophyllene, among others. 相似文献
12.
DNA extraction is difficult in many plants because of metabolites that interfere with DNA isolation procedures and subsequent
applications such as DNA restriction, amplification, and cloning. We developed the first reliable and efficient method for
isolatingVictoria amazonica genomic DNA that is free from polysaccharides and polyphenols. This protocol uses 1.5 M NaCl, 2% polyvinylpyrrolidone (PVP)
(Mr 1000), 5% mercaptoethanol, 0.12% sodium sulfite, and an incubation at 65°C for 4 h. The purity of isolated genomic DNA
was confirmed by means of high-performance liquid chromatography (HPLC) profile and spectrophotometric analyses (A260/230 ratio of 1.836, A260/280 of 1.842). DNA was obtained in the amount of 387 μg per gram of leaf material, and it proved amenable to restriction digestion. 相似文献
13.
An improved protocol for the isolation of DNA from dry material of someHesperis specimens is described. The isolated DNA is suitable for random amplification of polymorphic DNA (RAPD) analysis. Different
DNA extraction protocols were examined to determine which might yield DNA from dry leaf tissue ofHesperis specimens. The methods examined include the protocols with hexadecyltrimethylammonium bromide (CTAB) described by Doyle and
Doyle (1987); sodium dodecyl sulfate (SDS) by Dellaporta et al. (1983); and CTAB and SDS, the modified minipreparation, by
Dellaporta et al (1983). None of these procedures yielded DNA of suitable purity for RAPD assay. We established an improved
procedure involving CTAB and enzymatic digestion of proteins and RNA. The recovery of DNA with an average yield of 25 mg/g
of leaf material was possible with this procedure. RAPD bands, which could be used to distinguish amongHesperis specimens, were generated. 相似文献
14.
Introduction – Dehydrocavidine is a major component of Corydalis saxicola Bunting with sedative, analgesic, anticonvulsive and antibacterial activities. Conventional methods have disadvantages in extracting, separating and purifying dehydrocavidine from C. saxicola. Hence, an efficient method should be established. Objective – To develop a suitable preparative method in order to isolate dehydrocavidine from a complex C. saxicola extract by preparative HSCCC. Methodology – The methanol extract of C. saxicola was prepared by optimised microwave‐assisted extraction (MAE). The analytical HSCCC was used for the exploration of suitable solvent systems and the preparative HSCCC was used for larger scale separation and purification. Dehydrocavidine was analysed by high‐performance liquid chromatography (HPLC) and further identified by ESI‐MS and 1H NMR. Results – The optimised MAE experimental conditions were as follows: extraction temperature, 60°C; ratio of liquid to solid, 20; extraction time, 15 min; and microwave power, 700 W. In less than 4 h, 42.1 mg of dehydrocavidine (98.9% purity) was obtained from 900 mg crude extract in a one‐step separation, using a two‐phase solvent system composed of chloroform–methanol–0.3 m hydrochloric acid (4 : 0.5 : 2, v/v/v). Conclusion – Microwave‐assisted extraction coupled with high‐speed counter‐current chromatography is a powerful tool for extraction, separation and purification of dehydrocavidine from C. saxicola. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
Summary Anthers and ovaries of six grapevine cultivars (three Vitis vinifera L., two V × Labruscana L. H. Bailey, and one complex hybrid) were extracted from flower buds over 2 yr and cultured on three media reported to promote
somatic embryogenesis in Vitis tissues. The highest percent embryogenesis from the hybrid ‘Chancellor’ and V. vinifera ‘Chardonnay’, ‘Merlot’, and ‘Pinot Noir’ occurred on medium C [Nitsch and Nitsch, 1969, basal medium with 3.0% (w/v) sucrose,
0.01% (w/v) inositol. 0.3% (w/v) Phytagel, 2.5 μM 2.4-dichlorophenoxyacetic acid, 2.5μM β-naphthoxyacetic acid, 5.0μM N-(2-chloro-4-pyridyl)-N′-phenylurea, and 0.05% (w/v) glutamine]. Regardless of the media, the labrusca cultivars ‘Concord’ and ‘Niagara’ produced
soft non-embryogenic callus that was sometimes mixed with well-developed somatic embryos. Nine vinifera genotypes were further
tested for several different years on medium C. Embryogenic cultures suitable for transformation were obtained from all genotypes
in more than 1 yr. The average percent embryogenesis from ovaries was 7-fold higher than from anthers. There was significant
annual variation in percent embryogenesis, demonstrating the need for media comparisons to be replicated for more than one
season. Suspension cultures suitable for use in genetic transformation were initiated from ‘Chardonnay’, ‘Merlot,’ and ‘Pinot
Noir’ pro-embryogenic masses. ‘Chardonnay’ suspension cultures plated and grown under conditions developed for recovery of
plants after biolistic transformation yielded approximately 500 non-transformed embryos per plate after 4 mo. of culture,
with 68.6% of the embryos converting to plants. This is the first reported protocol for embryogenesis from ‘Concord,’ ‘Cabernet
Franc,’ and ‘Pinot Noir’ grapevines. 相似文献
16.
Isolation of high-quality DNA from rosaceous species is particularly difficult because of their high levels of polyphenols,
polysaccharides, and other compounds. The yields and quality of genomic DNA are considerably affected when the common protocol
for DNA isolation is applied to the chestnut rose (Rosa roxburghii Tratt). A simple, rapid, and efficient protocol for the extraction of DNA from the chestnut rose is described. The modified
hexadecyltrimethylammonium bromide (CTAB) procedure, which uses phenol-absent extraction to enhance the yield, involves a
washing step before extraction for the removal of organic molecules and excessive water; the use of high concentrations of
polyvinylpyrrolidone (2% [w/v]), CTAB (3% [w/v]), and β-mercaptoethanol (3% [v/v]) in the high-salt-concentration extraction
buffer to remove polyphenols and polysaccharides; and the combined use of potassium acetate and chloroform to remove proteins
and polysaccharides. Finally, DNA is precipitated with an equal volume of isopropanol and 0.1 vol of sodium acetate. This
protocol results in high yields of DNA. The average yield of DNA ranged from 980–1800 μg/g of fresh weight of leaves. Downstream
results indicate that DNA quality is sufficient for restriction fragment length polymorphism (RFLP) and polymerase chain reaction
(PCR) analyses. 相似文献
17.
A general in vitro cloning system was established for four Helleborus species: H. argutifolius, H. foetidus, H. niger and H. orientalis. The plant material was introduced in vitro from axillary buds. A Murashige and Skoog (MS)—based medium (Murashige and Skoog
1962) was used supplemented with 2% (w/v) sucrose, 2-isopentenyladenine (2-iP) and 6-benzylaminopurine (BA). Multiplication
rates depended on the genotype and varied from 1.3 for H. foetidus till 3.8 for H. niger. The first results showed that the rooting phase could be done ex vitro. Rooting was induced by a drench for one week in
a solution of indole-3-butyric acid (IBA -3 mg l−1) and 1-naphthaleneacetic acid (NAA-1 mg l−1) at 5°C. 相似文献
18.
A bioconversion process of producing GM1 (monosialotetrahexosylganglioside) on an industrial scale was developed with a novel
sialidase-producing strain Brevibacterium casei. The sialidase hydrolyzed polysialogangliosides to produce GM1 but did not act on GM1. When Brevibacterium casei was cultured in a synthetic medium containing crude pig brain gangliosides (10% w/v) at 30°C for 24 h in a 50 l fermenter,
most of the polysialogangliosides were converted to GM1. The content of GM1 was increased from 9% in crude gangliosides to
45% with 70% (w/w) yield. 相似文献
19.
S. H. Gan R. Ismail 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2001,759(2):287
An HPLC system using solid-phase extraction and HPLC with UV detection has been validated in order to determine tramadol and o-desmethyltramadol (M1) concentrations in human plasma. The method developed was selective and linear for concentrations ranging from 50 to 3500 ng/ml (tramadol) and 50 to 500 ng/ml (M1) with mean recoveries of 94.36±12.53% and 93.52±7.88%, respectively. Limit of quantitation (LOQ) was 50 ng/ml. For tramadol, the intra-day accuracy ranged from 95.48 to 114.64% and the inter-day accuracy, 97.21 to 103.24%. Good precision (0.51 and 18.32% for intra- and inter-day, respectively) was obtained at LOQ. The system has been applied to determine tramadol concentrations in human plasma samples for a pharmacokinetic study. 相似文献
20.
Currently, there are many reports in the literature regarding technological methods for paclitaxel purification. However,
there have been few reports on the purification of paclitaxel using a micellar system. This method is based on the transfer
of paclitaxel within the crude extract to an aqueous surfactant solution as a micelle, allowing the use of organic solvents
to be used for the removal of lipids and non-polar impurities. In this study, we optimized the important process parameters
of micellar extraction to obtain a high purity and yield of paclitaxel in a pre-purification step. The optimal surfactant
(N-cetylpyridinium chloride, CPC) concentration, initial crude paclitaxel concentration, organic solvents (methylt-butyl ether/hexane) ratio, extraction temperature, and extraction time were 7.5% (w/v), 16.4 mg/mL, 1.5/1 (v/v), 25°C, and
30 min, respectively. The crude extracts from the liquid-liquid extracts were efficiently pre-purified by micellar extraction,
increasing in purity from 6% to over 21%, with a yield of 92%. Overall, the use of micellar extraction in the pre-purification
process allowed for rapid and efficient separation of paclitaxel from interfering compounds, and dramatically increased the
yield and purity of the crucle paclitael for subsequent purification steps. 相似文献