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121.
Jian Yang Robert A. Spicer Teresa E. V. Spicer Nan Crystal Arens Frédéric M. B. Jacques Tao Su Elizabeth M. Kennedy Alexei B. Herman David C. Steart Gaurav Srivastava Rakesh C. Mehrotra Paul J. Valdes Naresh C. Mehrotra Zhe‐Kun Zhou Jiang‐Shan Lai 《Global Ecology and Biogeography》2015,24(10):1113-1125
122.
123.
Paul G. Schaberg Rakesh Minocha Stephanie Long Joshua M. Halman Gary J. Hawley Christopher Eagar 《Trees - Structure and Function》2011,25(6):1053-1061
Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable
of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology
of red spruce during the cold season, we measured concentrations of foliar polyamines and free amino acids (putative stress-protection
compounds), chlorophyll (a key photosystem component), and sapwood area (a proxy for foliar biomass), for trees in Ca-addition
(CaSiO3 added) and Ca-depleted (reference) watersheds at the Hubbard Brook Experimental Forest (NH, USA). Ca-addition increased concentrations
of the amino acids alanine and γ-aminobutyric acid (GABA) and the polyamines putrescine (Put) and spermidine (Spd) in November,
and Put in February relative to foliage from the reference watershed. Consistent with increased stress protection, foliage
from the Ca-addition watershed had higher total chlorophyll and chlorophyll a concentrations in February than foliage from the reference watershed. In contrast, foliage from the reference watershed had
significantly lower glutamic acid (Glu) and higher alanine (Ala) concentrations in February than foliage from the Ca-addition
watershed. Imbalances in Ala:Glu have been attributed to cold sensitivity or damage in other species. In addition to concentration-based
differences in foliar compounds, trees from the Ca-addition watershed had higher estimated levels of foliar biomass than trees
from the reference watershed. Our findings suggest that Ca-addition increased the stress tolerance and productive capacity
of red spruce foliage during the cold season, and resulted in greater crown mass compared to trees growing on untreated soils. 相似文献
124.
Inge Everaert Antien Mooyaart Audrey Baguet Ana Zutinic Hans Baelde Eric Achten Youri Taes Emile De Heer Wim Derave 《Amino acids》2011,40(4):1221-1229
Carnosine is found in high concentrations in skeletal muscles, where it is involved in several physiological functions. The
muscle carnosine content measured within a population can vary by a factor 4. The aim of this study was to further characterize
suggested determinants of the muscle carnosine content (diet, gender and age) and to identify new determinants (plasma carnosinase
activity and testosterone). We investigated a group of 149 healthy subjects, which consisted of 94 men (12 vegetarians) and
55 women. Muscle carnosine was quantified in M. soleus, gastrocnemius and tibialis anterior using magnetic resonance proton
spectroscopy and blood samples were collected to determine CNDP1 genotype, plasma carnosinase activity and testosterone concentrations. Compared to women, men have 36, 28 and 82% higher
carnosine concentrations in M. soleus, gastrocnemius and tibialis anterior muscle, respectively, whereas circulating testosterone
concentrations were unrelated to muscle carnosine levels in healthy men. The carnosine content of the M. soleus is negatively
related to the subjects’ age. Vegetarians have a lower carnosine content of 26% in gastrocnemius compared to omnivores. In
contrast, there is no difference in muscle carnosine content between omnivores with a high or low ingestion of β-alanine.
Muscle carnosine levels are not related to the polymorphism of the CNDP1 gene or to the enzymatic activity of the plasma carnosinase. In conclusion, neither CNDP1 genotype nor the normal variation in circulating testosterone levels affects the muscular carnosine content, whereas vegetarianism,
female gender and increasing age are the factors associated with reduced muscle carnosine stores. 相似文献
125.
Kumar M Rawat P Khan MF Rawat AK Srivastava AK Maurya R 《Bioorganic & medicinal chemistry letters》2011,21(8):2232-2237
16-Dehydropregnenolone undergoes a smooth annulation with propan-1-amine and aromatic aldehydes. Several amine derivatives of 16- dehydropregnenolone were synthesized and evaluated as inhibitors of DPP-IV. The structures of compounds were confirmed by 1H, 13C, NMR and mass spectral analysis. Among 17 compounds evaluated only five compounds 1, 9, 13, 15 and 16 demonstrated significant inhibition of DPP. This study suggest that introduction of appropriate substituents in the 16-dehydropregnenolone plays an important role in DPP-IV inhibitory activity. 相似文献
126.
Rao VK Chhikara BS Shirazi AN Tiwari R Parang K Kumar A 《Bioorganic & medicinal chemistry letters》2011,21(12):3511-3514
An efficient and economical method was developed for the synthesis of 3-substituted indoles by one-pot three-component coupling reaction of a substituted or unsubstituted benzaldehyde, N-methylaniline, and indole or N-methylindole using Yb(OTf)3-SiO2 as a catalyst. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. The 4-methylphenyl (4o and 4p) and 4-methoxyphenyl (4q) indole derivatives inhibited the cell proliferation of SK-OV-3 and HT-29 cells by 70-77% at a concentration of 50 μM. The unsubstituted phenyl (4d) and 3-nitrophenyl (4l) derivatives showed the inhibition of c-Src kinase with IC50 values of 50.6 and 58.3 μM, respectively. 相似文献
127.
Low E Kim B Francavilla C Shiau TP Turtle ED O'Mahony DJ Alvarez N Houchin A Xu P Zuck M Celeri C Anderson MB Najafi RR Jain RK 《Bioorganic & medicinal chemistry letters》2011,21(12):3682-3685
Structure stability/activity relationships (SXR) of a new class of N,N-dichloroamine compounds were explored to improve antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans while maintaining aqueous solution stability. This study identified a new class of solution-stable and topical antimicrobial agents. These agents are sulfone-stabilized and possess either a quaternary ammonium or sulfonate appendages as a water solubilizing group. Several unique challenges were confronted in the synthesis of these novel compounds which are highlighted in the discussion. 相似文献
128.
Daljit Singh Arora Rakesh Kumar SharmaPriyanka Chandra 《International biodeterioration & biodegradation》2011,65(2):352-358
A variety of methods for feed development have been introduced during last few years. Bioprocessed agricultural residues may prove a better alternative to provide animal feed. For the purpose, some white rot fungi were allowed to degrade wheat straw up to 30 days under solid state conditions. Several parameters including loss in total organic matter, ligninolysis, in vitro digestibility of wheat straw and estimation of different antioxidant activities were studied. All the fungi were able to degrade lignin and enhance the in vitro digestibility. Among all the tested fungi, Phlebia brevispora degraded maximum lignin (30.6%) and enhanced the digestibility from 172 to 287 g/kg. Different antioxidant properties of fungal degraded wheat straw were higher as compared to the uninoculated control straw. Phlebia floridensis found to be more efficient organism in terms of higher antioxidant activity (70.8%) and total phenolic content (9.8 mg/ml). Thus, bioprocessing of the wheat straw with the help of these organisms seems to be a better approach for providing the animal feed in terms of enhanced digestibility, higher protein content, higher antioxidant activity and availability of biomass. 相似文献
129.
A putative epoxide hydrolase-encoding gene was identified from the genome sequence of Cupriavidus metallidurans CH34. The gene was cloned and overexpressed in Escherichia coli with His(6)-tag at its N-terminus. The epoxide hydrolase (CMEH) was purified to near homogeneity and was found to be a homodimer, with subunit molecular weight of 36 kDa. The CMEH had broad substrate specificity as it could hydrolyze 13 epoxides, out of 15 substrates tested. CMEH had high specific activity with 1,2-epoxyoctane, 1,2-epoxyhexane, styrene oxide (SO) and was also found to be active with meso-epoxides. The enzyme had optimum pH and temperature of 7.5 and 37°C respectively, with racemic SO. Biotransformation of 80 mM SO with recombinant whole E. coli cells expressing CMEH led to 56% ee(P) of (R)-diol with 77.23% conversion in 30 min. The enzyme could hydrolyze (R)-SO, ~2-fold faster than (S)-SO, though it accepted both (R)- and (S)-SO with similar affinity as K(m)(R) and K(m)(S) of CMEH were 2.05±0.42 and 2.11±0.16 mM, respectively. However, the k(cat)(R) and k(cat)(S) for the two enantiomers of SO were 4.80 and 3.34 s(-1), respectively. The wide substrate spectrum exhibited by CMEH combined with the fast conversion rate makes it a robust biocatalyst for industrial use. Regioselectivity studies with enantiopure (R)- and (S)-SO revealed that with slightly altered regioselectivity, CMEH has a high potential to synthesize an enantiopure (R)-PED, through an enantioconvergent hydrolytic process. 相似文献
130.