84 research outputs found

    Synthesis and biological evaluation of a novel series of 2-(2'-isopropyl-5'-methylphenoxy)acetyl amino acids and dipeptides

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    A series of new 2-(2'-isopropyl-5'-methylphenoxy)acetyl amino acids and peptides have been synthesized by coupling the 2-(2'-isopropyl-5'-methylphenoxy)acetic acid with amino acid methyl esters/dipeptides using DCC as coupling agent and TEA as base. The structures were elucidated by elemental analyses as well as FTIR, 1H NMR, 13C NMR and MS spectral data. The newly synthesized compounds were also evaluated for antibacterial and antifungal activities. Compounds (2, 6 and 15) were found to exhibit potent antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus and compounds (13, 14 and 16) were found to be potent antifungal agents against pathogenic Candida albicans.KEY WORDS: Phenoxy acetic acid, Amino acids, Dipeptides, Antibacterial activity, Antifungal activity.Bull. Chem. Soc. Ethiop. 2006, 20(2), 235-245

    Prva potpuna sinteza i biološko vrednovanje himenamida E

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    A new potent bioactive, proline-rich cyclic heptapeptide hymenamide E (13) was synthesized using the solution phase technique by cyclization of the linear peptide Boc-Phe-Pro-Thr-Thr-Pro-Tyr-Phe-OMe (12) after proper deprotection at carboxyl and amino terminals. Linear peptide segment was prepared by coupling the tripeptide unit Boc-Phe-Pro-Thr-OH (10a) with the tetrapeptide unit Thr-Pro-Tyr-Phe-OMe (11a) using dicyclohexylcarbodiimide as the coupling agent and N-methylmorpholine as the base. Structures of all new compounds were characterized by IR, 1H NMR spectral data as well as elemental analyses. In addition, the structure of compound 13 was verified by 13C NMR, fast atom bombardment mass spectroscopy and differential scanning calorimetry. The newly synthesized cyclopeptide was screened for its antibacterial, antifungal and anthelmintic activities against eight pathogenic microbes and two earthworm species. Compound 13 showed potent antifungal activity against Candida albicans and Ganoderma species comparable to that of griseofulvin as a reference drug and potent anthelmintic activity against earthworms Megascoplex konkanensis and Eudrilus species in comparison to piperazine citrate.Novi biološki aktivni ciklički heptapeptid himenamid E (13) sintetiziran je ciklizacijom linearnog peptida Boc-Phe-Pro-Thr-Thr-Pro-Tyr-Phe-OMe (12) nakon uklanjanja zaštitnih skupina sa C-terminalnih i N-terminalnih aminokiselina. Linearni peptidni segment pripravljen je spajanjem tripeptidne jedinice Boc-Phe-Pro-Thr-OH (10a) s tetrapeptidnom jedinicom Thr-Pro-Tyr-Phe-OMe (11a) u prisutnosti dicikloheksilkarbodiimida i N-metilmorfolina kao baze. Strukture novih spojeva potvrđene su IR i 1H NMR spektroskopijom i elementarnom analizom, a struktura spoja 13 i 13C NMR, spektroskopijom masa i diferencijalnom pretražnom kalorimetrijom. Novosintetizirani ciklopeptid testiran je na antibakterijsko, antifungalno i anthelmintičko djelovanje na osam patogenih mikroorganizama i dva parazita. Spoj 13 snažno djeluje antifungalno na gljivice Candida albicans i vrste Ganoderma i anthelmintički na nametnike Megascoplex konkanensis i vrste Eudrilus. Kao poredbene ljekovite tvari uporabljeni su grizeofulvin i piperazin citrat

    Prva potpuna sinteza i biološko vrednovanje himenamida E

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    A new potent bioactive, proline-rich cyclic heptapeptide hymenamide E (13) was synthesized using the solution phase technique by cyclization of the linear peptide Boc-Phe-Pro-Thr-Thr-Pro-Tyr-Phe-OMe (12) after proper deprotection at carboxyl and amino terminals. Linear peptide segment was prepared by coupling the tripeptide unit Boc-Phe-Pro-Thr-OH (10a) with the tetrapeptide unit Thr-Pro-Tyr-Phe-OMe (11a) using dicyclohexylcarbodiimide as the coupling agent and N-methylmorpholine as the base. Structures of all new compounds were characterized by IR, 1H NMR spectral data as well as elemental analyses. In addition, the structure of compound 13 was verified by 13C NMR, fast atom bombardment mass spectroscopy and differential scanning calorimetry. The newly synthesized cyclopeptide was screened for its antibacterial, antifungal and anthelmintic activities against eight pathogenic microbes and two earthworm species. Compound 13 showed potent antifungal activity against Candida albicans and Ganoderma species comparable to that of griseofulvin as a reference drug and potent anthelmintic activity against earthworms Megascoplex konkanensis and Eudrilus species in comparison to piperazine citrate.Novi biološki aktivni ciklički heptapeptid himenamid E (13) sintetiziran je ciklizacijom linearnog peptida Boc-Phe-Pro-Thr-Thr-Pro-Tyr-Phe-OMe (12) nakon uklanjanja zaštitnih skupina sa C-terminalnih i N-terminalnih aminokiselina. Linearni peptidni segment pripravljen je spajanjem tripeptidne jedinice Boc-Phe-Pro-Thr-OH (10a) s tetrapeptidnom jedinicom Thr-Pro-Tyr-Phe-OMe (11a) u prisutnosti dicikloheksilkarbodiimida i N-metilmorfolina kao baze. Strukture novih spojeva potvrđene su IR i 1H NMR spektroskopijom i elementarnom analizom, a struktura spoja 13 i 13C NMR, spektroskopijom masa i diferencijalnom pretražnom kalorimetrijom. Novosintetizirani ciklopeptid testiran je na antibakterijsko, antifungalno i anthelmintičko djelovanje na osam patogenih mikroorganizama i dva parazita. Spoj 13 snažno djeluje antifungalno na gljivice Candida albicans i vrste Ganoderma i anthelmintički na nametnike Megascoplex konkanensis i vrste Eudrilus. Kao poredbene ljekovite tvari uporabljeni su grizeofulvin i piperazin citrat

    Effect of super-optimal levels of fertilizers on soil enzymatic activities during growth stages of wheat crop on an Inceptisol

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    A field experiment was conducted during 2010-2011 and 2011-2012 to investigate the effect of optimal (100% NPK) to super-optimal doses (200% NPK) of mineral fertilizers on soil enzymes such as dehydrogenase (DHA), acid phosphatase (Ac-PA), alkaline phosphatase (Alk-PA), fluorescien diacetate hydrolysis (FDA), urease and nitrate reductase (NRA) at three physiological stages (CRI, anthesis and maturity) of wheat crop on an Inceptisol. Dehydrogenase activity was reduced by 28-37% when fertilizer application was at super-optimal dose (200% NPK), whereas, urease and NRA responded positively in the range of 43-44% and 213-231% respectively. Alk-PAwas 7.3-7.9% higher in treatments receiving 125% NPK as compared to control (100% NPK); whereas, Ac-PA declines in the plots receiving 175 and 200% of recommended dose of fertilizer (RDF) as compared to 150% NPK levels. Addition of 175% RDF increased the FDA to the tune of 46-53% as compared to 100% NPK. A significant (P?0.05) positive interaction between fertilizer treatments and physiological stages of wheat growth was observed on soil enzyme activities (except urease and NRA) being highest at the anthesis stage of wheat. Correlation matrix analysis showed that DHA was correlated with the studied enzyme activities except Ac-PA and FDA; whereas, strong correlation was observed between urease and NRA (r=0.981, P=0.01). This study provides theoretical and practical base for avoiding super optimal application of fertilisers which hinders the enzyme activities and vis-a-vis sustainable nutrient enrichment under rhizosphere

    Coarse race data conceals disparities in clinical risk score performance

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    Healthcare data in the United States often records only a patient's coarse race group: for example, both Indian and Chinese patients are typically coded as ``Asian.'' It is unknown, however, whether this coarse coding conceals meaningful disparities in the performance of clinical risk scores across granular race groups. Here we show that it does. Using data from 418K emergency department visits, we assess clinical risk score performance disparities across granular race groups for three outcomes, five risk scores, and four performance metrics. Across outcomes and metrics, we show that there are significant granular disparities in performance within coarse race categories. In fact, variation in performance metrics within coarse groups often exceeds the variation between coarse groups. We explore why these disparities arise, finding that outcome rates, feature distributions, and the relationships between features and outcomes all vary significantly across granular race categories. Our results suggest that healthcare providers, hospital systems, and machine learning researchers should strive to collect, release, and use granular race data in place of coarse race data, and that existing analyses may significantly underestimate racial disparities in performance.Comment: The first two authors contributed equally. Under revie

    Genome-wide study predicts promoter-G4 DNA motifs regulate selective functions in bacteria: radioresistance of D. radiodurans involves G4 DNA-mediated regulation

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    A remarkable number of guanine-rich sequences with potential to adopt non-canonical secondary structures called G-quadruplexes (or G4 DNA) are found within gene promoters. Despite growing interest, regulatory role of quadruplex DNA motifs in intrinsic cellular function remains poorly understood. Herein, we asked whether occurrence of potential G4 (PG4) DNA in promoters is associated with specific function(s) in bacteria. Using a normalized promoter-PG4-content (PG4P) index we analysed >60 000 promoters in 19 well-annotated species for (a) function class(es) and (b) gene(s) with enriched PG4P. Unexpectedly, PG4-associated functional classes were organism specific, suggesting that PG4 motifs may impart specific function to organisms. As a case study, we analysed radioresistance. Interestingly, unsupervised clustering using PG4P of 21 genes, crucial for radioresistance, grouped three radioresistant microorganisms including Deinococcus radiodurans. Based on these predictions we tested and found that in presence of nanomolar amounts of the intracellular quadruplex-binding ligand N-methyl mesoporphyrin (NMM), radioresistance of D. radiodurans was attenuated by ∼60%. In addition, important components of the RecF recombinational repair pathway recA, recF, recO, recR and recQ genes were found to harbour promoter-PG4 motifs and were also down-regulated in presence of NMM. Together these results provide first evidence that radioresistance may involve G4 DNA-mediated regulation and support the rationale that promoter-PG4s influence selective functions

    Investigation of some trace elements in Raipur Industrial area and its surrounding, Raipur District.

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    The paper deals with determination of eight trace metals namely. Copper, Iron, Mangnese, Zinc, Nickel,, Chromium  Lead and Mercury  in the ground water of different sites of Raipur Industrial area of Raipur district . All activities carried out on the ground surface have direct or indirect impact on the ground water whether associated with urban ,industrial or agricultural activities large scale concentrated source of pollutants, such as industrial discharges and sub surface injection of chemicals and hazardous are obvious source of ground water pollutants. This study was carryout in the month of during summer 2013. The samples were collected from seven different source of Raipur Industrial area of Raipur. The results obtained are compared with safe limits in ppm for heavy metals laid down by BIS, WHO, ICMR, APHA

    An important role of coal and its calorific value on the performance of thermal power station: A case study

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    An investigation was undertaken to study the Physical and Chemical properties of coal in Korba district. Due to the Presence of lot of Coal mines, number of coal based thermal power stations are established in Korba district. So study has been carried out for assessment of coal quality, whether it is suitable for thermal power stations, by collectying sample from Gevra Coal mines. This paper presents Grade of the coal available in Korba district. Three different Coal samples were collected from  different areas of Gevra Coal mines  and analyzed for Proximate, Ultimate and  Calorific value as per Standard methods. The useful heat values (UHV) of three coal samples are 2482K.Cal/Kg, 2917K.Cal/Kg, and 2786K.Cal/Kg. From overall analysis, and according to UHV of coal samples  we can conclude that  the grade of Gevra Coal is” F”and is very much  useful for Coal based thermal power stations
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