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61.
62.
Crocker PJ Mahadevan A Wiley JL Martin BR Razdan RK 《Bioorganic & medicinal chemistry letters》2007,17(6):1504-1507
A facile synthesis of 1-fluoro-1-deoxy-Delta(8)-THC analogs with side chains seven carbons in length, in the alkane/ene/yne- series (6, 5, and 4), was achieved from 1-fluoro-3,5-dimethoxybenzene (1). In vitro studies show that substitution by a fluorine has a significant detrimental effect on CB1 binding which is supported by in vivo testing. The implications of these results on the SAR of classical cannabinoids are discussed. 相似文献
63.
Electrochemistry of microperoxidase-11 (MPx-11) anchored on the mixed self-assembled monolayer (SAM) of 2-(2-mercaptoethylpyrazine) (PET) and 4,4'-dithiodibutyric acid (DTB) on gold (Au) electrode and the biosensing of uric acid (UA) is described. MPx-11 has been covalently anchored on the mixed SAM of PET and DTB on Au electrode. MPx-11 on the mixed self-assembly exhibits reversible redox response characteristic of a surface confined species. The heterocyclic ring of PET promotes the electron transfer between the electrode and the redox protein. The apparent standard rate constant kapps obtained for the redox reaction of MPx-11 on the mixed monolayer is approximately 2.15 times higher than that on the single monolayer of DTB modified electrode. MPx-11 efficiently mediates the electrocatalytic reduction of H2O2. MPx-11 electrode is highly sensitive to H2O2 and it shows linear response for a wide concentration range. The electrocatalytic activity of the MPx-11 electrode is combined with the enzymatic activity of uricase (UOx) to fabricate uric acid biosensor. The bienzyme assembly is highly sensitive towards UA and it could detect UA as low as 2 microM at the potential of -0.1 V. The biosensor shows linear response with a sensitivity of 3.4+/-0.08 nA cm(-2) microM(-1). Ascorbate (AA) and paracetamol (PA) do not significantly interfere in the amperometric sensing of UA. 相似文献
64.
Two main gene orders exist in birds: the ancestral gene order and the remnant control region (CR) 2 gene order. These gene orders differ by the presence of 1 or 2 copies of the CR, respectively. Among songbirds, Oscines were thought to follow the ancestral gene order, with the exception of the lyrebird and Phylloscopus warblers. Here, we determined the complete mitochondrial genome sequence of 3 non-Phylloscopus warblers species and found that the blackcap (Sylvia atricapilla) and the reed warbler (Acrocephalus scirpaceus) have 2 almost identical copies of the CR, whereas the eastern orphean warbler (Sylvia crassirostris) follows the remnant CR 2 gene order. Our results contradict previous studies suggesting that Acrocephalus and most sylvioid warblers exhibit the ancestral gene order. We were able to trace this contradiction to a misidentification of gene order from polymerase chain reaction length determination. We thus suggest that passerine gene order evolution needs to be revised. 相似文献
65.
Thomas P J Solomon Sakita N Sistrun Raj K Krishnan Luis F Del Aguila Christine M Marchetti Susan M O'Carroll Valerie B O'Leary John P Kirwan 《Journal of applied physiology》2008,104(5):1313-1319
Older, obese, and sedentary individuals are at high risk of developing diabetes and cardiovascular disease. Exercise training improves metabolic anomalies associated with such diseases, but the effects of caloric restriction in addition to exercise in such a high-risk group are not known. Changes in body composition and metabolism during a lifestyle intervention were investigated in 23 older, obese men and women (aged 66 +/- 1 yr, body mass index 33.2 +/- 1.4 kg/m(2)) with impaired glucose tolerance. All volunteers undertook 12 wk of aerobic exercise training [5 days/wk for 60 min at 75% maximal oxygen consumption (Vo(2max))] with either normal caloric intake (eucaloric group, 1,901 +/- 277 kcal/day, n = 12) or a reduced-calorie diet (hypocaloric group, 1,307 +/- 70 kcal/day, n = 11), as dictated by nutritional counseling. Body composition (decreased fat mass; maintained fat-free mass), aerobic fitness (Vo(2max)), leptinemia, insulin sensitivity, and intramyocellular lipid accumulation (IMCL) in skeletal muscle improved in both groups (P < 0.05). Improvements in body composition, leptin, and basal fat oxidation were greater in the hypocaloric group. Following the intervention, there was a correlation between the increase in basal fat oxidation and the decrease in IMCL (r = -0.53, P = 0.04). In addition, basal fat oxidation was associated with circulating leptin after (r = 0.65, P = 0.0007) but not before the intervention (r = 0.05, P = 0.84). In conclusion, these data show that exercise training improves resting substrate oxidation and creates a metabolic milieu that appears to promote lipid utilization in skeletal muscle, thus facilitating a reversal of insulin resistance. We also demonstrate that leptin sensitivity is improved but that such a trend may rely on reducing caloric intake in addition to exercise training. 相似文献
66.
Kohli E Gaspari M Raj HG Parmar VS Sharma SK van der Greef J Kumari R Gupta G Seema Khurana P Tyagi YK Watterson AC Olsen CE 《Biochimica et biophysica acta》2004,1698(1):55-66
The purification and characterization of the buffalo liver microsomal transacetylase (TAase) catalyzing the transfer of acetyl groups from a model acetoxy drug: 7,8-diacetoxy-4-methylcoumarin (DAMC) to GST3-3 has been described here. The enzyme was routinely assayed using DAMC and cytosolic GST as the substrates and was partially purified from microsomes of the buffalo liver. The enzyme was found to have approximate molecular of weight 65 kDa. The action of TAase and DAMC on liver cytosolic GST resulted in the formation of monoacetoxymonohydroxy-4-methylcoumarin (MAMHC) and 7,8-dihydroxy-4-methylcoumarin (DHMC), although the former was the major metabolite. The buffalo liver microsomal TAase exhibited hyperbolic kinetics and yielded K(m) (1667 microM) and V(max) (192 units) when the concentration of DAMC was varied keeping the concentration of GST constant. After having characterized the nature of the substrates and a product of the TAase-catalyzed reaction, we set out to identify the acetylated protein which is another product of the reaction. GST3-3 was used as a model protein substrate for the action of TAase using DAMC as the acetyl donor. The subunit of control and modified GST3-3 were separated by SDS-polyacrylamide gel electrophoresis (PAGE) and digested with trypsin. The tryptic peptides were extracted from the gel pieces and analyzed by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOFMS). The data search for calibrated and labeled mass peaks of peptides was performed on the Matrix Science Server using the search engine Mascot. The peptide maps so obtained covered 97% of the GST3-3 sequence. On comparison of MALDI peptide maps of modified and control GST, seven new peaks were recognized corresponding to the potentially acetylated peptides in peptide map. The mass value of each of them was 42 Da higher than the theoretical mass of a non-modified GST3-3 tryptic peptide, strongly suggesting acetylation. By examining the fragmentation patterns and by comparing experimental and predicted values for MS/MS daughter ions, the identity of the seven acetylated GST tryptic peptides could be confirmed by the application of LC/MS/MS. In the modified GST, N-terminal proline and six lysines (Lys(51), Lys(82), Lys(123), Lsy(181), Lys(191) and Lys(210)) were found to be acetylated. The structure of acetylated GST revealed that the lysines that underwent acetylation were peripheral in positions. 相似文献
67.
Aziz Sheikh Laila Halani Raj Bhopal Gopalakrishnan Netuveli Martyn R. Partridge Josip Car Chris Griffiths Mark Levy 《PLoS medicine》2009,6(10)
Background
There is international interest in enhancing recruitment of minority ethnic people into research, particularly in disease areas with substantial ethnic inequalities. A recent systematic review and meta-analysis found that UK South Asians are at three times increased risk of hospitalisation for asthma when compared to white Europeans. US asthma trials are far more likely to report enrolling minority ethnic people into studies than those conducted in Europe. We investigated approaches to bolster recruitment of South Asians into UK asthma studies through qualitative research with US and UK researchers, and UK community leaders.Methods and Findings
Interviews were conducted with 36 researchers (19 UK and 17 US) from diverse disciplinary backgrounds and ten community leaders from a range of ethnic, religious, and linguistic backgrounds, followed by self-completion questionnaires. Interviews were digitally recorded, translated where necessary, and transcribed. The Framework approach was used for analysis. Barriers to ethnic minority participation revolved around five key themes: (i) researchers'' own attitudes, which ranged from empathy to antipathy to (in a minority of cases) misgivings about the scientific importance of the question under study; (ii) stereotypes and prejudices about the difficulties in engaging with minority ethnic populations; (iii) the logistical challenges posed by language, cultural differences, and research costs set against the need to demonstrate value for money; (iv) the unique contexts of the two countries; and (v) poorly developed understanding amongst some minority ethnic leaders of what research entails and aims to achieve. US researchers were considerably more positive than their UK counterparts about the importance and logistics of including ethnic minorities, which appeared to a large extent to reflect the longer-term impact of the National Institutes of Health''s requirement to include minority ethnic people.Conclusions
Most researchers and community leaders view the broadening of participation in research as important and are reasonably optimistic about the feasibility of recruiting South Asians into asthma studies provided that the barriers can be overcome. Suggested strategies for improving recruitment in the UK included a considerably improved support structure to provide academics with essential contextual information (e.g., languages of particular importance and contact with local gatekeepers), and the need to ensure that care is taken to engage with the minority ethnic communities in ways that are both culturally appropriate and sustainable; ensuring reciprocal benefits was seen as one key way of avoiding gatekeeper fatigue. Although voluntary measures to encourage researchers may have some impact, greater impact might be achieved if UK funding bodies followed the lead of the US National Institutes of Health requiring recruitment of ethnic minorities. Such a move is, however, likely in the short- to medium-term, to prove unpopular with many UK academics because of the added “hassle” factor in engaging with more diverse populations than many have hitherto been accustomed to. Please see later in the article for the Editors'' Summary 相似文献68.
Gluconic acid (GA) is a multifunctional carbonic acid regarded as a bulk chemical in the food, feed, beverage, textile, pharmaceutical,
and construction industries. The favored production process is submerged fermentation by Aspergillus niger utilizing glucose as a major carbohydrate source, which accompanied product yield of 98%. However, use of GA and its derivatives
is currently restricted because of high prices: about US$ 1.20–8.50/kg. Advancements in biotechnology such as screening of
microorganisms, immobilization techniques, and modifications in fermentation process for continuous fermentation, including
genetic engineering programmes, could lead to cost-effective production of GA. Among alternative carbohydrate sources, sugarcane
molasses, grape must show highest GA yield of 95.8%, and banana must may assist reducing the overall cost of GA production.
These methodologies would open new markets and increase applications of GA.
Authors’ contributions OVS and RK are the sole contributors of this original review article. This review is based upon the published research in
the area of gluconic acid fermentation. 相似文献
69.
In view of rising prices of crude oil due to increasing fuel demands, the need for alternative sources of bioenergy is expected
to increase sharply in the coming years. Among potential alternative bioenergy resources, lignocellulosics have been identified
as the prime source of biofuels and other value-added products. Lignocelluloses as agricultural, industrial and forest residuals
account for the majority of the total biomass present in the world. To initiate the production of industrially important products
from cellulosic biomass, bioconversion of the cellulosic components into fermentable sugars is necessary. A variety of microorganisms
including bacteria and fungi may have the ability to degrade the cellulosic biomass to glucose monomers. Bacterial cellulases
exist as discrete multi-enzyme complexes, called cellulosomes that consist of multiple subunits. Cellulolytic enzyme systems
from the filamentous fungi, especially Trichoderma reesei, contain two exoglucanases or cellobiohydrolases (CBH1 and CBH2), at least four endoglucanases (EG1, EG2, EG3, EG5), and
one β-glucosidase. These enzymes act synergistically to catalyse the hydrolysis of cellulose. Different physical parameters
such as pH, temperature, adsorption, chemical factors like nitrogen, phosphorus, presence of phenolic compounds and other
inhibitors can critically influence the bioconversion of lignocellulose. The production of cellulases by microbial cells is
governed by genetic and biochemical controls including induction, catabolite repression, or end product inhibition. Several
efforts have been made to increase the production of cellulases through strain improvement by mutagenesis. Various physical
and chemical methods have been used to develop bacterial and fungal strains producing higher amounts of cellulase, all with
limited success. Cellulosic bioconversion is a complex process and requires the synergistic action of the three enzymatic
components consisting of endoglucanases, exoglucanases and β-glucosidases. The co-cultivation of microbes in fermentation
can increase the quantity of the desirable components of the cellulase complex. An understanding of the molecular mechanism
leading to biodegradation of lignocelluloses and the development of the bioprocessing potential of cellulolytic microorganisms
might effectively be accomplished with recombinant DNA technology. For instance, cloning and sequencing of the various cellulolytic
genes could economize the cellulase production process. Apart from that, metabolic engineering and genomics approaches have
great potential for enhancing our understanding of the molecular mechanism of bioconversion of lignocelluloses to value added
economically significant products in the future.
JIMB 2008: BioEnergy - Special issue. 相似文献
70.
Puspa Raj Poudel Ikuo Kataoka Ryosuke Mochioka 《Plant Cell, Tissue and Organ Culture》2008,92(2):147-153
The effect of red- and blue-light-emitting diodes on shoot and root growth of Hybrid Franc grape, a rootstock cultivar, along
with two other grape genotypes, Kadainou R-1 and Vitis ficifolia var. ganebu, were investigated in vitro. Plants cultured under red-light-emitting diodes produced the longest shoots with longer internodes
for all genotypes. The chlorophyll content measured as SPAD value and leaf number per explant were highest on plants cultured
under blue-light-emitting diodes in all the genotypes. Blue light was also responsible for a higher number of stomata in all
the genotypes; however, there was no significant difference in size of stomata in all genotypes under the different light
conditions tested. Different light-emitting diodes did not affect the rooting percentage of Hybrid Franc but red-light-emitting
diodes gave a higher rooting percentage along with higher root numbers for the two other grape genotypes. 相似文献