Enicostemins A and B, New Secoiridoids from Enicostemma verticillatum

2011 ◽  
Vol 66 (7) ◽  
pp. 749-751
Author(s):  
Erum Jahan ◽  
Itrat Fatima ◽  
Abdul Malik
Keyword(s):  
Soluble Fraction ◽  
Spectroscopic Studies ◽  
First Time

The new secoiridoids Enicostemins A (1) and B (2) were isolated from the n-butanol-soluble fraction of Enicostemma verticillatum along with gentiocrucine (3) and rutin (4), which were isolated for the first time from the genus Verticillatum. Their structures were assigned based on spectroscopic studies.

Dihydroquinol And Quinol Derivatives From Ajuga Parviflora

2001 ◽  
Vol 56 (8) ◽  
pp. 842-846 ◽  
Author(s):  
Erum Akbar ◽  
Hafiz Rub Nawaz ◽  
Abdul Malik
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Soluble Fraction ◽  
Spectroscopic Studies ◽  
First Time

Dihydroquinol derivative 1, quinol glucopyranoside 2 and quinol derivative 3 have been isolated from the ethyl acetate soluble fraction of Ajuga parviflora and their structures have been elucidated through spectroscopic studies as methyl 2-[2,2-dimethyl-6-oxo-7-dihydro-1,3- benzodioxol-3(6H)-yl]aceate (1), 2-hydroxy-4β-methyl-4a-(β-D-glucopyranoside)-2,5-cyclohexadien- 1-one (2) and (4-oxo-2,5-cyclohexadien-1-yl)acetic acid (3). The known quinol 4 has also been isolated for the first time from this species

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

Enzyme Inhibiting Terpenoids from Amberboa ramosa

2004 ◽  
Vol 59 (5) ◽  
pp. 579-583 ◽  
Author(s):  
Sher B. Khan ◽  
Abdul Malik ◽  
Nighat Afza ◽  
Nusrat Jahan ◽  
Azhar U. Haq ◽  
...  
Keyword(s):  
2D Nmr ◽  
Spectroscopic Studies ◽  
Inhibitory Potential ◽  
First Time ◽  
Amberboa Ramosa

Abstract Two new cycloartane type triterpenes 1 and 2 have been isolated from Amberboa ramosa. Their structures were established as (22R)-cycloart-20, 25-dien-2α,3β ,22α-triol 1 and (22R)-cycloart-23- ene-3β ,22α, 25-triol 2 through spectroscopic studies including 2D-NMR. The known compounds 3,4-epoxyguaia-1(10), 11(13)-dien-6, 12-olide 3, and 5-hydroxy 7,8,2’,3’-tetramethoxyflavone 4 are also reported for the first time from this species. The compounds 1 and 2 displayed inhibitory potential against butyrylcholinesterase.

scholarly journals Thymofolinoates A and B, New Cinnamic Acid Derivatives from Euphorbia thymifolia

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701
Author(s):  
Riaz Hussain ◽  
Bakhat Ali ◽  
Muhammad Imran ◽  
Abdul Malik
Keyword(s):  
Cinnamic Acid ◽  
Nmr Spectra ◽  
Soluble Fraction ◽  
Cinnamic Acid Derivatives ◽  
First Time ◽  
C Nmr

Two new cinnamic acid derivatives, thymofolinoates A (1) and B (2) have been isolated from the chloroform soluble fraction of Euphorbia thymifolia and their structures assigned from 1H and 13C NMR spectra, DEPT and by 2D COSY, HMQC and HMBC experiments. In addition, p-hydroxy cinnamic acid (3), 5-hydroxy-6,7,8,4′-tetramethoxy flavone (4), and 5-hydroxy-3′,4′,6,7,8-pentamethoxy flavone (5) have also been isolated for the first time from this species.

scholarly journals Probing the Redshift Desert Using the Gemini Deep Deep Survey: Observing Galaxy Mass Assembly at z > 1

2005 ◽  
Vol 216 ◽  
pp. 390-397
Author(s):  
Karl Glazebrook ◽  
Keyword(s):  
Spectroscopic Studies ◽  
Star Forming ◽  
Hubble Sequence ◽  
First Results ◽  
Deep Survey ◽  
Redshift Survey ◽  
Mass Assembly ◽  
Galaxy Assembly ◽  
First Time ◽  
The Universe

The aim of the Gemini Deep Deep Survey is to push spectroscopic studies of complete galaxy samples (both red and blue objects) significantly beyond z = 1; this is the redshift where the current Hubble sequence of ellipticals and spirals is already extant. In the Universe at z = 2 the only currently spectroscopically confirmed galaxies are blue, star-forming and of fragmented morphology. Exploring this transition means filling the ‘redshift desert’ 1 < z < 2 where there is a dearth of spectroscopic measurements. To do this we need to secure redshifts of the oldest, reddest galaxies (candidate ellipticals) beyond z > 1 which has led us to carry out the longest exposure redshift survey ever done: 100 ksec spectroscopic MOS exposures with GMOS on Gemini North. We have developed an implementation of the CCD “nod & shuffle” technique to ensure precise sky-subtraction in these ultra-deep exposures. At the halfway mark the GDDS now has ∼ 36 galaxies in the redshift desert 1.2 < z < 2 extending up to z = 1.97 and I < 24.5 with secure redshifts based on weak rest-frame UV absorption features complete for both red, old objects and young, blue objects. The peak epoch of galaxy assembly is now being probed by direct spectroscopic investigation for the first time. on behalf of the GDDS team I present our first results on the properties of galaxies in the ‘redshift desert’.

Crystal Structure of a Novel Furo-Furan Lactone from Heliotropium eichwaldi

2012 ◽  
Vol 67 (3) ◽  
pp. 269-271
Author(s):  
Sadiqa Firdous ◽  
Nida Hassan Ansari ◽  
Seik Weng Ngb ◽  
Sammer Yousuf ◽  
Abdul Malik
Keyword(s):  
Crystal Structure ◽  
Ethyl Acetate ◽  
Soluble Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report ◽  
First Time

A novel furo-furan lactone 1 has been isolated as fine needles from the ethyl acetate-soluble fraction of Heliotropium eichwaldi. This is the first report of any furo-furan from the genus Heliotropium. β -Sitosterol 3-O-β -D-glucoside 2 has also been obtained for the first time from this source. The structure of 1 was elucidated by X-ray diffraction studies.

scholarly journals The Nature of Ultraluminous Infrared Galaxies

2001 ◽  
Vol 204 ◽  
pp. 179-191
Author(s):  
Eckhard Sturm
Keyword(s):  
Far Infrared ◽  
Spectroscopic Studies ◽  
Infrared Galaxies ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Infrared Spectroscopic ◽  
Ultraluminous Infrared Galaxies ◽  
First Time

The Infrared Space Observatory (ISO) has for the first time made possible mid- and far-infrared spectroscopic studies of nearby and moderate redshift, dusty ultraluminous infrared galaxies (ULIRGs). We discuss recent SWS, LWS, ISOPHOT-S and ISOCAM (CVF) results on ULIRGs, addressing the following topics: What powers ULIRGs? What is the AGN-starburst connection? How do ULIRGs evolve? What is the connection of the local ULIRG population to the recently discovered population of mid-IR to submillimeter sources?

Catalyst Free, Nitromethane Assisted Facile Ring Opening of Epoxide with Less Reactive Aromatic Amines

2020 ◽  
Author(s):  
Sumit Kumar ◽  
Meenakshi Bansal ◽  
Charu Upadhyay ◽  
Maria Grishina ◽  
Vladimir Potemkin ◽  
...  
Keyword(s):  
Aromatic Amines ◽  
Ring Opening ◽  
Spectroscopic Studies ◽  
Bioactive Scaffolds ◽  
Chemistry Research ◽  
Ring Opening Reactions ◽  
Ring Opening Of Epoxide ◽  
Sterically Hindered ◽  
First Time ◽  
Nucleophilic Ring Opening

<p>Nucleophilic ring opening reactions of epoxides with aromatic amines are in the forefront of the synthetic organic chemistry research to build new bioactive scaffolds. Here, a convenient, green and highly efficient regioselective ring opening of sterically hindered (2R,3S)-3-(<i>N</i>-Boc-amino)-1-oxirane-4-phenylbutane with various poorly reactive aromatic amines are accomplished under microwave irradiation in nitromethane. All the reactions effectively implemented for various aromatic amines involves reuse of nitromethane that supports its dual role as a solvent and catalyst. The corresponding new β-alcohol analogs of hydroxyethylamine (HEA) are isolated in 41-98% yields. The reactions proceed under mild conditions for a broad range of less reactive and sterically hindered aromatic amines. Proton NMR and UV-visible spectroscopic studies suggest that the nucleophilicity of amines is influenced by nitromethane, which is substantiated by the extensive computational studies. Overall, this methodology elucidates the first time use of nitromethane as a solvent for the ring opening reactions under microwave conditions involving equimolar ratio of epoxide and aromatic amine without any catalyst, facile ring opening of complex epoxide by less reactive aromatic amines, low reaction time, less energy consumption, recycling of the solvent and simple workup procedures.</p>

In vitro folding and characterization of the p53 DNA binding domain

2004 ◽  
Vol 385 (1) ◽  
pp. 95-102 ◽  
Author(s):  
C. Klein ◽  
F. Hesse ◽  
A. Dehner ◽  
R. A. Engh ◽  
M. Schwaiger ◽  
...  
Keyword(s):  
Dna Binding ◽  
Soluble Fraction ◽  
Spectroscopic Studies ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Efficient Procedure ◽  
Factorial Matrix ◽  
Transcription Factor P53

Abstract The transcription factor p53 acts as major tumor suppressor and is inactivated by mutation in more than 50% of all human tumors. We have established an efficient procedure for the in vitro folding and purification of the p53 DNA binding domain (p53DBD) using a modified factorial matrix approach that supplies large amounts of homogeneous (isotope-labeled) p53DBD for application in biochemical, crystallographic and NMR spectroscopic studies. We further show with biophysical methods that in vitro folded p53DBD is fully functional and that its conformation is identical to that obtained from the soluble fraction.

Oleanane Glycosides from Eclipta prostrata

1970 ◽  
Vol 4 (2) ◽  
Author(s):  
Mohammad S Rahman ◽  
Rasheduzzaman Chowdhury ◽  
Chodhury M Hasan ◽  
Mohammad A Rashid
Keyword(s):  
Key Words ◽  
13C Nmr ◽  
Full Text ◽  
High Field ◽  
Stem Bark ◽  
Spectroscopic Studies ◽  
Hexane Extract ◽  
Nmr Data ◽  
Eclipta Prostrata ◽  
First Time

Two oleanane-type glycosides eclalbasaponin II (1) and eclalbasaponin I (2) along with the ubiquitous steroid, stigmasterol were isolated from an n-hexane extract of the stem bark of Eclipta prostrata. The structures of the isolated compounds were confirmed by extensive spectroscopic studies, notably high field NMR and MS. The 13C NMR data of the parent saponins 1 and 2 are reported here for the first time. Key words: Eclipta prostrata, Compositae, Oleanane glycoside, Eclalbasaponin I, Eclalbasaponin II. Dhaka Univ. J. Pharm. Sci. Vol.4(2) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

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