scholarly journals Two New Terpenoids from Trichilia quadrijuga (Meliaceae)

2010 ◽  
Vol 5 (2) ◽  
pp. 1934578X1000500
Author(s):  
Virginia F. Rodrigues ◽  
Hadria M. Carmo ◽  
Raimundo Braz Filho ◽  
Leda Mathias ◽  
Ivo J. Curcino Vieira
Keyword(s):  
Data Analysis ◽  
Spectral Data ◽  
Mass Spectra ◽  
2D Nmr ◽  
Spectral Data Analysis ◽  
C Nmr

Two new terpenoids, ambrosanoli-10(14)-en-11,12-diol (1), a sesquiterpene named quadrijugol, and a pregnane steroid, 3β,4β-dihydroxypregnan-16-one (2), were isolated from the stem and leaves of Trichilia quadrijuga, along with eleven known compounds, spathulenol, kudtdiol, 2β,3β,4β-trihydroxypregnan-16-one, bourjotinolone B, piscidinol, niloticin, dihydroniloticin, β-sitosterol, 3-O-β-D-glucopyranosyl-sitosterol, itesmol and stigmasterol. Structures were elucidated by spectral data analysis, mainly afforded by 1H and 13C NMR (1D and 2D NMR HMQC, HMBC, NOESY and COSY) and mass spectra.

scholarly journals A New Isocoumarin from Cajanus cajan (Fabaceae)

2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Virginia F. Rodrigues ◽  
Rodrigo R. Oliveira ◽  
Maria Raquel G. Vega
Keyword(s):  
Spectral Data ◽  
Cajanus Cajan ◽  
Mass Spectra ◽  
2D Nmr ◽  
C Nmr

A new isocoumarin, 3-phenyl-8-hydroxy-6-methoxy-5-γ, γ-dimethylallyl-isocoumarin, named cajavilmina (1) and eight known compounds: α-amirenone (2), β-amirenone (3), lupenone (4), 5-hydroxy-7-methoxydihydroflavone (5), longistilin C (6), 3-hydroxy-5-methoxystilbene (7), β-sitosterol (8) and stigmasterol (9) were identified in a dichloromethane fraction from Cajanus cajan leaves. Structures were elucidated by analysis of spectral data, mainly those afforded by 1H, NOEDIFF and 13C NMR (1D and 2D NMR HMQC, HMBC and COSY) and mass spectra.

scholarly journals Mumunine - A New Carbazole Alkaloid from Murraya koenigii (Linn.) Spreng

2020 ◽  
Vol 12 (4) ◽  
pp. 665-672
Author(s):  
M. Chakraborty
Keyword(s):  
Data Analysis ◽  
Spectral Data ◽  
Structure Elucidation ◽  
2D Nmr ◽  
Rich Source ◽  
Murraya Koenigii ◽  
Spectral Data Analysis ◽  
Carbazole Alkaloids

The plant Murraya koenigii, commonly known as curry leaf tree is a rich source of carbazole alkaloids. A number of monomeric as well as dimeric carbazoles with C13, C18 and C23 skeleton have been isolated from the plant. In my present work, a new carbazole alkaloid, designated as mumunine, was isolated from the bark of Murraya koenigii (Linn) Spreng, along with a known carbazole alkaloid, viz. mahanimbine. The structure of the new alkaloid 1 was elucidated on the basis of 1D and 2D NMR spectral data analysis. In this paper, the isolation and structure elucidation of the new compound will be discussed in detail.

scholarly journals C-15 ACETOGENINS FROM THE MARINE ALGA Chondria

2010 ◽  
Vol 8 (3) ◽  
pp. 443-447
Author(s):  
Antonius R.B. Ola ◽  
Bruce F. Bowden
Keyword(s):  
Data Analysis ◽  
Spectral Data ◽  
Marine Alga ◽  
2D Nmr ◽  
Red Alga ◽  
Spectral Data Analysis

(-) Z-Pinnatifidenyne, a novel C-15 acetogenin has been isolated along with the known compound (+)-3Z,6R,7R-obtusenyne and (+) (3Z)-laurenyne from the Australian red alga Chondria armata. The structures of the compounds were elucidated based on spectral data analysis including 2D NMR spectroscopic experiment.   Keywords: Chondria armata, C-15 acetogenin, 2D NMR

Synthesis of 2-amino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-thiazines

1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč
Keyword(s):  
Spectral Data ◽  
Chlorine Atom ◽  
Mass Spectra ◽  
High Reactivity ◽  
Secondary Amines ◽  
Dimroth Rearrangement ◽  
H Nmr ◽  
New Synthesis ◽  
C Nmr

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.

Chemical components of the rhizomes of Drynaria fortunei (KUNZE) J. Sm. (polypodiaceae) in Vietnam

2011 ◽  
Vol 76 (9) ◽  
pp. 1133-1139 ◽  
Author(s):  
Pham Thi Nhat Trinh ◽  
Nguyen Cong Hao ◽  
Phan Thanh Thao ◽  
Le Tien Dung
Keyword(s):  
Data Analysis ◽  
Spectral Data ◽  
Phenolic Acid ◽  
Ethanol Extract ◽  
Chemical Components ◽  
Spectroscopic Methods ◽  
Phenylpropanoid Glycoside ◽  
Spectral Data Analysis ◽  
First Time

From the ethanol extract of Drynaria fortunei (KUNZE) J. Sm., a new phenylpropanoid glycoside, fortunamide (1), was isolated and characterized by spectroscopic methods. Together with a new glycoside, 9 known compounds, including three curcuminoids (2–4), two isoprenylated flavonoids (5, 6), two flavonoids (7, 8), one monoterpenoid (9) and one phenolic acid (10) were isolated and identified by spectral data analysis from the rhizomes of Drynaria fortunei (KUNZE) J. Sm. Eight of them were isolated from Drynaria fortunei (KUNZE) J. Sm. for the first time.

scholarly journals Quantitative Spectral Data Analysis Using Extreme Learning Machines Algorithm Incorporated with PCA

Algorithms ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 18
Author(s):  
Michael Li ◽  
Santoso Wibowo ◽  
Wei Li ◽  
Lily D. Li
Keyword(s):  
Data Analysis ◽  
Conceptual Framework ◽  
Spectral Data ◽  
Learning Algorithm ◽  
Structural Parameters ◽  
Inverse Function ◽  
Principal Component ◽  
Learning Task ◽  
Classification Problems ◽  
Spectral Data Analysis

Extreme learning machine (ELM) is a popular randomization-based learning algorithm that provides a fast solution for many regression and classification problems. In this article, we present a method based on ELM for solving the spectral data analysis problem, which essentially is a class of inverse problems. It requires determining the structural parameters of a physical sample from the given spectroscopic curves. We proposed that the unknown target inverse function is approximated by an ELM through adding a linear neuron to correct the localized effect aroused by Gaussian basis functions. Unlike the conventional methods involving intensive numerical computations, under the new conceptual framework, the task of performing spectral data analysis becomes a learning task from data. As spectral data are typical high-dimensional data, the dimensionality reduction technique of principal component analysis (PCA) is applied to reduce the dimension of the dataset to ensure convergence. The proposed conceptual framework is illustrated using a set of simulated Rutherford backscattering spectra. The results have shown the proposed method can achieve prediction inaccuracies of less than 1%, which outperform the predictions from the multi-layer perceptron and numerical-based techniques. The presented method could be implemented as application software for real-time spectral data analysis by integrating it into a spectroscopic data collection system.

Coumarins and a Naphthyl Labdanoate Diarabinoside from the Fruits of Peucedanum grande C. B. Clarke

2012 ◽  
Vol 67 (11-12) ◽  
pp. 580-586 ◽  
Author(s):  
Mohammad Aslam ◽  
Mohammed Ali ◽  
Rameshwar Dayal ◽  
Kalim Javed
Keyword(s):  
Data Analysis ◽  
Spectral Data ◽  
Chemical Reactions ◽  
Wistar Rats ◽  
Methanolic Extract ◽  
Nephroprotective Activity ◽  
Coumarin 1 ◽  
Spectral Data Analysis

Phytochemical investigations of the methanolic extract of the fruits of Peucedanum grande C. B. Clarke (Apiaceae) led to the identification of three coumarins and a naphthyl labdanoate diarabinoside characterized as 5-hydroxy-6-isopranyl coumarin (1), 5,6-furanocoumarin (2), 7-methoxy-5,6-furanocoumarin (3), and labdanyl-3α-ol-18-(3’’’-methoxy-2’’’- naphthyl-oate)-3α-L-arabinofuranosyl-(2’→1’’)-α-L-arabinofuranoside (4). The structures of these compounds were identified on the basis of spectral data analysis and chemical reactions. The methanolic extract and 4 showed nephroprotective activity against gentamicininduced nephrotoxicity in Wistar rats.

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