scholarly journals Pregnane Derivatives from Potentilla evestita

2011 ◽  
Vol 6 (8) ◽  
pp. 1934578X1100600
Author(s):  
Rehan Khan ◽  
Farah Siddiq ◽  
Itrat Fatima ◽  
Shazia Yasmeen ◽  
Aman Karim ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Natural Product ◽  
Nmr Spectra ◽  
Soluble Fraction ◽  
First Time ◽  
C Nmr

A new pregnane derivative, 2,6β,7β-trihydroxy-4-methyl-19-norpregna-1,3,5(10)-trien-17-one, has been isolated from the ethyl acetate soluble fraction of Potentilla evestita along with a pregnane derivative, 11α,17α,21-trihydroxypregna-4,16(22)-diene-3,20-dione, that is reported for the first time as a natural product. Their structures were elucidated with the aid of 1H and 13C NMR spectra and by COSY, HMQC, HMBC and NOESY experiments.

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.

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.

Kinetics of the reaction of p-dinitrobenzene with basic hydrogen peroxide

1987 ◽  
Vol 65 (2) ◽  
pp. 251-255 ◽  
Author(s):  
Raymond A. Heller ◽  
Richard Weiler
Keyword(s):  
Hydrogen Peroxide ◽  
Strong Evidence ◽  
Nmr Spectra ◽  
Visible Region ◽  
Kinetic Studies ◽  
Aqueous Dioxane ◽  
First Time ◽  
Kinetics Of ◽  
Basic Hydrogen Peroxide ◽  
C Nmr

Kinetic studies of the reaction of p-dinitrobenzene with H2O2 and NaOH in 10%, 30%, and 50% aqueous dioxane have been carried out at 30.0 °C. The reaction involves the formation of a reasonably stable intermediate which absorbs strongly in the visible region, with the rate of formation being about 18 times faster than the rate of conversion to final product which is p-nitrophenol. Proton and 13C nmr spectra of the kinetic solution provide strong evidence that the intermediate is p-nitrophenyl hydroperoxide, apparently the first time that a true aryl peroxide species has been identified.

scholarly journals Antialactone: A New γ-Lactone from Antiaris Africana, and its Absolute Configuration Determined from TDDFT CD Calculations

2008 ◽  
Vol 3 (2) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Vouffo Bertin ◽  
Hidayat Hussain ◽  
Simeon F. Kouam ◽  
Etienne Dongo ◽  
Gennaro Pescitelli ◽  
...  
Keyword(s):  
Natural Product ◽  
Absolute Configuration ◽  
Betulinic Acid ◽  
Spectroscopic Data ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Stem Bark ◽  
Cd Spectra ◽  
2D Nmr Spectra ◽  
First Time

Four compounds were isolated from the stem bark of Antiaris africana. One of them, a γ-lactone named antialactone (1a), is reported for the first time as a natural product. The structures were determined by comprehensive analyses of their 1D and 2D NMR spectra and EI MS data. The absolute configuration of antialactone acetate (1b) was established by TDDFT CD calculations and comparison with measured CD spectra. The remaining three known compounds were identified, by comparing their spectroscopic data with those reported in the literature, as lichenxanthone, β-sitosterol, and betulinic acid.

Theoretical and experimental studies of IR and NMR spectra of gem-2,2-diamino-4,4,6,6-tetraphenoxy-1,3,5-cyclo-triaza-λ5-phosphorine

2010 ◽  
Vol 75 (11) ◽  
pp. 1125-1138
Author(s):  
Lenka Dastychová ◽  
Dalibor Dastych ◽  
Pavel Kubáček ◽  
Milan Alberti
Keyword(s):  
Density Functional ◽  
Nmr Spectra ◽  
Experimental Studies ◽  
Normal Modes ◽  
Chemical Calculation ◽  
Functional Theory ◽  
Calculation Results ◽  
Vibrational Bands ◽  
First Time ◽  
C Nmr

The vibrational spectra of gem-2,2-diamino-4,4,6,6-tetraphenoxy-1,3,5-cyclo-triaza-λ5-phosphorine were studied using density functional theory. Selected vibrational bands were assigned to normal modes on the basis of DFT calculation with the ADF program package. The 1H and 13C NMR spectra, the higher order 31P, 31P{1Ham.(sel.)} and 31P{1Harom.(sel.)} NMR spectra were measured and the values of 1J(C,H), 2J(C,H) and 2J(PI,PII) were found. Nearly the complete spin system (ABB′M4X4X4′) for the symmetry C2 was simulated with the gNMR simulation program and the values of 2J(PI,Ham.), 4J(PII,Ham.), 4J(PII,Harom.), 6J(PI,Harom.) and 6J(PII,H′arom.) were determined for the first time. The experimental NMR data were also compared with quantum chemical calculation results.

A THEORETICAL INVESTIGATION OF STRUCTURAL, SPECTROSCOPIC AND THERMODYNAMIC PROPERTIES OF CYCLODECANE

2007 ◽  
Vol 06 (02) ◽  
pp. 281-299 ◽  
Author(s):  
DALVA E. C. FERREIRA ◽  
WAGNER B. DE ALMEIDA ◽  
HÉLIO F. DOS SANTOS
Keyword(s):  
Quantum Chemical ◽  
Nmr Spectra ◽  
Energy Surface ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Torsion Potential ◽  
Good Accordance ◽  
First Time ◽  
Good Agreement ◽  
C Nmr

The torsion potential energy surface for cyclodecane has been examined using molecular mechanics and quantum chemical methods. The boat-chair-boat (BCB) conformer is predicted as the most stable structure at all levels of theory employed, in agreement with low temperature experiments. We found 13 low-energy conformers that cover a range of ~10 kcal mol-1. The relative abundance of the main isomers (named BCB, TBC, TBCC and TCCC) as a function of the temperature is discussed. In addition, energy calculations at high correlated levels of theory (MP4(SDTQ) and CCSD(T)) were for the first time performed for these conformations. In general, the predicted Gibbs population is in fairly good agreement with the experimental data. The simulated IR, VCD and 13 C NMR spectra were obtained showing good accordance with the observed data, providing important features for conformational analysis of cyclodecane.

scholarly journals Cytotoxic Sesquiterpene Lactones of Egyptian Tanacetum santolinoides

2007 ◽  
Vol 2 (8) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Diaa T. A. Youssef ◽  
Mahmoud A. Ramadan ◽  
Sabrin R. M. Ibrahim ◽  
Jihan M. Badr
Keyword(s):  
Cytotoxic Activity ◽  
Brine Shrimp ◽  
Nmr Spectra ◽  
Methanolic Extract ◽  
Soluble Fraction ◽  
Sesquiterpene Lactones ◽  
Natural Source ◽  
Mass Spectral ◽  
Aerial Parts ◽  
First Time

The chloroform soluble fraction of the methanolic extract of the aerial parts of Tanacetum santolinoides afforded six sesquiterpene lactones. Tanacetolide A (1) was isolated for the first time from a natural source, in addition to five known sesquiterpene lactones. The structures were established on the basis of extensive studies of their 1D and 2D (1H-1H COSY, HMQC, HMBC, HOHAHA and NOESY) NMR spectra and FAB mass spectral determinations. The compounds showed good cytotoxic activity when tested using the brine shrimp bioassay.

scholarly journals Sessilifol A and B, Urease Inhibitory Pimarane-type Diterpenes from Hymenocrater sessilifolius

2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Sadia Khan ◽  
Muhammad Shaiq Ali ◽  
Zeeshan Ahmed ◽  
Mehreen Lateef ◽  
Sammer Yousuf ◽  
...  
Keyword(s):  
Single Crystal ◽  
Vanillic Acid ◽  
Nmr Spectra ◽  
Soluble Fraction ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inhibitory Potential ◽  
Urease Inhibitory ◽  
C Nmr

New pimarane type diterpenes named sessilifol A (1) and B (2) have been isolated from the EtOH soluble fraction of Hymenocrater sessilifolius Benth., along with eight known constituents cirsimaritin (3), gardenin C (4), β-sitosterol (5), saringosterol (6), β-sitosterol glucoside (7), ursolic acid (8), sucrose (9) and vanillic acid (10). Their structures were elucidated on the basis of 1H- and 13C-NMR spectra and by 2D-NMR experiments. The structure of 1 was further confirmed by single crystal X-ray diffraction technique. The compound 2 showed potent inhibitory potential against the enzyme urease while 1, 3, 4 and 10 were moderately active.

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

Antifungal Compounds in the Ethyl Acetate Soluble Fraction of the Extractives of Taiwania (Taiwania cryptomerioides Hayata) Heartwood

Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Shang-Tzen Chang ◽  
Sheng-Yang Wang ◽  
Chi-Lin Wu ◽  
Yu-Chang Su ◽  
Yueh-Hsiung Kuo
Keyword(s):  
Antifungal Activity ◽  
Ethyl Acetate ◽  
Column Chromatography ◽  
Soluble Fraction ◽  
Coriolus Versicolor ◽  
Antifungal Compounds ◽  
H Nmr ◽  
Laetiporus Sulphureus ◽  
Taiwania Cryptomerioides ◽  
C Nmr

Summary This study was to isolate and identify the antifungal compounds in the ethyl acetate soluble fraction of the methanol extractives of Taiwania (Taiwania cryptomerioides Hayata) heartwood and to examine their antifungal activity. Five compounds were obtained by open column chromatography and HPLC and based upon the results from Mass, 1H-NMR, and 13C-NMR analyses. Their structures were identified, namely ferruginol, helioxanthin, savinin, taiwanin C, and hinokiol. According to the results of antifungal test, the order of antifungal index of these compounds for Coriolus versicolor (L. ex Fr.) Quel. was ferruginol > taiwanin C > savinin > hinokiol. For Laetiporus sulphureus (B. ex Fr.) Bond. it was taiwanin C > savinin > ferruginol > hinokiol.

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