Clionamide, a major metabolite of the sponge Clionacelata Grant

1979 ◽  
Vol 57 (17) ◽  
pp. 2325-2328 ◽  
Author(s):  
Raymond J. Andersen ◽  
Richard J. Stonard
Keyword(s):  
Spectral Analysis ◽  
Spectral Data ◽  
Major Metabolite ◽  
Chemical Degradation ◽  
Hydrogenation Product ◽  
Cliona Celata

Clionamide, the major metabolite of the burrowing sponge Cliona celata, has been isolated. The structure of clionamide (1) was shown to be (2S)-N-((1E)-5,6,7-trihydroxystyr-1-yl)-2-amino-3-(6-bromoindol-3-yl)propionamide by spectral analysis and by interconversion to its tetracetyl derivative 2. The structure of 2 was determined from spectral data and extensive chemical degradation and was confirmed by the synthesis of its ultimate hydrogenation product, N-(5,6,7-triacetoxypheneth-1-yl)-2-acetamido-3-(indol-3-yl)propionamide (11).

Base-catalyzed Degradations of Carbohydrates. III. Formation of a Novel Perester from 1-O-Acetyl-3-deoxy-2,4,6-tri-O-methyl-α-D-erytho-hex-2-enopyranose

1973 ◽  
Vol 51 (3) ◽  
pp. 388-393 ◽  
Author(s):  
G. O. Aspinall ◽  
R. R. King ◽  
Zofia Pawlak
Keyword(s):  
Acetic Anhydride ◽  
Spectral Data ◽  
Trifluoroacetic Acid ◽  
Oxidative Degradation ◽  
Chemical Degradation ◽  
Reductive Decomposition

1-O-Acetyl-3-deoxy-2,4,6-tri-O-methyl-α-D-erythro-hex-2-enopyranose (1) reacts with m-chloroperbenzoic acid to give a novel perester, which has been assigned the structure 1,2-O-(1′-m-chloroperbenzoyl-oxyethylidene)-2-methoxy-4,6-di-O-methyl-α-D-glucopyranose (2), on the basis of spectral data and chemical degradation. The perester 2 and the derived acetate 3 undergo oxidative degradation on treatment with trifluoroacetic acid to give 3,5-di-O-methyl- (4) and 2-O-acetyl-3,5-di-O-methyl-D-arabinonolactone (5), respectively. Reductive decomposition of the acetylated perester 3 yields 1,3-di-O-acetyl-4,6-di-O-methyl-α-D-arabino-hexopyranosulose (6), which, on treatment with acetic anhydride in pyridine, gives successively 1,2,3-tri-O-acetyl-4,6-di-O-methyl-α-D-erythro-hex-2-enopyranose (7), 2-O-acetyl-1-deoxy-4,6-di-O-methyl-α-D-erythro-hex-1-enopyranose-3-ulose (8), and 5-acetoxy-2-(methoxy-methyl)-4H-pyran-4-one (9).

scholarly journals Two new Aromatic Glycosides from a Soil Bacterium Burkholderia gladioli OR1

2016 ◽  
Vol 11 (5) ◽  
pp. 1934578X1601100
Author(s):  
Afsana Khan ◽  
Pratibha Bharti ◽  
Isha Saraf ◽  
Neha Mittal ◽  
Rupinder Tewari ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Aromatic Aldehyde ◽  
Culture Broth ◽  
Soil Bacterium ◽  
Chemical Degradation ◽  
Burkholderia Gladioli

Two new aromatic glycosides, named as gladioside I (1) and II (2) were isolated from the culture broth of a soil bacterium, Burkholderia gladioli OR1. Both 1 and 2 contained one unit each of rhamnose and 3- O-methyl xylose and differed from each other in the aglycone part. Compound 1 contained an aromatic aldehyde and compound 2 contained a styrylcarbamate unit as the aglycone part. The structures of 1 and 2 were elucidated by detailed spectral analysis and chemical degradation.

Bildung von Cyclonucleotiden bei Bestrahlung wäßriger Lösungen von Purinnucleotiden

1968 ◽  
Vol 23 (8) ◽  
pp. 1034-1043 ◽  
Author(s):  
Klaus Keck
Keyword(s):  
Nmr Spectroscopy ◽  
Aqueous Solutions ◽  
Spectral Data ◽  
Chemical Degradation

A 8,5′-cyclonucleotide was shown to be a product in the γ-radiolysis of oxygen-free aqueous solutions of adenosine-5′-monophosphate. Evidence for this was obtained by NMR-spectroscopy and chemical degradation to 8-formyladenine, 8-hydroxymethyladenine and 8-carboxyadenine. The chromatographic and spectral data of these compounds are given. Irradiation of other purinnucleotides leads to similar cyclonucleotides.

The synthesis of 8-aza-3-deazaguanosine [6-amino-1-(β-D-ribofuranosyl)-υ-triazolo[4,5-c]pyridin-4-one] via a novel 1,3-dipolar cycloaddition reaction

1980 ◽  
Vol 58 (23) ◽  
pp. 2550-2561 ◽  
Author(s):  
Robert A. Earl ◽  
Leroy B. Townsend
Keyword(s):  
Spectral Data ◽  
Good Yield ◽  
Liquid Ammonia ◽  
Functional Group ◽  
Proton Nmr ◽  
Cycloaddition Reaction ◽  
Chemical Degradation ◽  
Dipolar Cycloaddition ◽  
Nuclear Overhauser Enhancement ◽  
Nuclear Overhauser

8-Aza-3-deazaguanosine (2) bas been prepared via a route which used a 1,3-dipolar cycloaddition reaction to provide a key intermediate. The reaction of 2′,3′,5′-tri-O-benzoyl-β-D-ribofuranosyl azide (13) with methyl 4-hydroxy-2-butynoate (11) provided a good yield of crystalline methyl 5-hydroxymethyl-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-υ-triazole-4-carboxylate (14). A series of functional group transformations were then used to convert 14 into methyl 5-cyanomethyl-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-υ-triazolo-4-carboxylate (19). Treatment of 19 with liquid ammonia effected not only a smooth removal of the blocking groups, but also an aminolysis of the ester function which was then followed by a ring annulation to provide 8-aza-3-deazaguanosine (2). The structures of these nucleosides were established on the basis of proton nmr spectral data and nuclear Overhauser enhancement data. The nucleosides obtained in this study were also converted through a chemical degradation sequence into nucleosides which had been obtained during an earlier work from our laboratory. The present study also provides unequivocal proof of the structures of some triazole nucleosides obtained in the earlier study.

scholarly journals X-ray study of spatial structures in Tycho’s supernova remnant using unsupervised deep learning

2019 ◽  
Vol 488 (3) ◽  
pp. 4106-4116 ◽  
Author(s):  
Hiroyoshi Iwasaki ◽  
Yuto Ichinohe ◽  
Yasunobu Uchiyama
Keyword(s):  
Spectral Analysis ◽  
Deep Learning ◽  
Spectral Data ◽  
Supernova Remnant ◽  
Rapid Development ◽  
Feature Space ◽  
Gaussian Mixture ◽  
Spatial Structures ◽  
X Ray ◽  
Unsupervised Deep Learning

ABSTRACT Recent rapid development of deep learning algorithms, which can implicitly capture structures in high-dimensional data, opens a new chapter in astronomical data analysis. We report here a new implementation of deep learning techniques for X-ray analysis. We apply a variational autoencoder (VAE) using a deep neural network for spatio-spectral analysis of data obtained by Chandra X-ray Observatory from Tycho’s supernova remnant (SNR). We established an unsupervised learning method combining the VAE and a Gaussian mixture model (GMM), where the dimensions of the observed spectral data are reduced by the VAE, and clustering in feature space is performed by the GMM. We found that some characteristic spatial structures, such as the iron knot on the eastern rim, can be automatically recognized by this method, which uses only spectral properties. This result shows that unsupervised machine learning can be useful for extracting characteristic spatial structures from spectral information in observational data (without detailed spectral analysis), which would reduce human-intensive preprocessing costs for understanding fine structures in diffuse astronomical objects, e.g. SNRs or galaxy clusters. Such data-driven analysis can be used to select regions from which to extract spectra for detailed analysis and help us make the best use of the large amount of spectral data available currently and arriving in the coming decades.

scholarly journals Synthesis and Spectral Analysis of 3,4,5-trichloro-6-(dibenzo[d,f][1,3]diazepin-5-yl)-[1,2]-benzoquinones

2011 ◽  
Vol 8 (s1) ◽  
pp. S91-S96 ◽  
Author(s):  
Mohsen A. M. Gomaa
Keyword(s):  
Spectral Analysis ◽  
Ethyl Acetate ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Room Temperature

Reaction ofN1,N2-di-(4-methoxyphenyl)- orN1,N2-di-(4-hydroxyphenyl) -amidines (1a-d) with 3,4,5,6-tetrachloro-1,2-benzoquinone (2) in ethyl acetate at room temperature led to formation of new 3,4,5-trichloro-6-(2-hydroxy-6-methyldibenzo[d,f][1,3]diazepin-5-yl[1,2]-benzoquinones (3a-d) in addition toN-aryl-N'-(6,7,8,9-tetrachloro-4-hydroxydibenzo-[1,4]dioxin-2-yl)acetamidines (4a,b). The rational of formation of products3a-dand4a,bwas discussed and structures were confirmed on the basis of elemental analysis and spectral data.

scholarly journals Spectral Analysis of Azo Derivatives for their Colorimetric Response to some Special Metal Ions

2021 ◽  
Vol 11 (3) ◽  
pp. 3909-3916
Keyword(s):  
Spectral Analysis ◽  
Metal Ions ◽  
Aqueous Medium ◽  
Spectral Data ◽  
Azo Dyes ◽  
Color Change ◽  
Oh Groups ◽  
Sensing Properties ◽  
Colorimetric Response ◽  
Azo Derivatives

The present study describes an efficient chromogenic probing ability possessed by an azo linkage that could sense Ni, Fe, and Co in the semi-aqueous medium. The chromogenic sensing properties of the four azo dyes were studied towards Fe(III), Co(II), and Ni(II) ions, the IR and UV-VIS spectral data revealed that the nitrogen and oxygen atoms of –N=N-, C=O and –OH groups participated in bonding with the metal ions. Also, an obvious change in the color of the azo dyes A and B solution from yellow to dark brown in the case of Fe+2 metal ions and Co+2 and Ni+2 colorless solutions appeared yellowish, while the addition of other metal ions did not cause any color change. These results imply that the two azo dyes are viable, portable chromogenic chemosensors for the detection of Fe (III), Co (II), and Ni (II) ions in various biological and environmental fields.

scholarly journals Oceanalin B, a Hybrid α,ω-Bifunctionalized Sphingoid Tetrahydroisoquinoline β-Glycoside from the Marine Sponge Oceanapia sp.

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 635
Author(s):  
Tatyana N. Makarieva ◽  
Natalia V. Ivanchina ◽  
Pavel S. Dmitrenok ◽  
Alla G. Guzii ◽  
Valentin A. Stonik ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Antifungal Activity ◽  
Natural Product ◽  
Marine Sponge ◽  
Biological Activities ◽  
Chemical Degradation ◽  
Etoh Extract ◽  
Absolute Stereochemistry ◽  
In Vitro Antifungal Activity

Oceanalin B (1), an α,ω-bipolar natural product belonging to a rare family of sphingoid tetrahydoisoquinoline β-glycosides, was isolated from the EtOH extract of the lyophilized marine sponge Oceanapia sp. as the second member of the series after oceanalin A (2) from the same animal. The compounds are of particular interest due to their biogenetically unexpected structures as well as their biological activities. The structure and absolute stereochemistry of 1 as a α,ω-bifunctionalized sphingoid tetrahydroisoquinoline β-glycoside was elucidated using NMR, CD and MS spectral analysis and chemical degradation. Oceanalin B exhibited in vitro antifungal activity against Candidaglabrata with a MIC of 25 μg/mL.

scholarly journals Portable Smart Spectrometer Integrated with Blockchain and Big Data Technology

2019 ◽  
Vol 9 (16) ◽  
pp. 3279
Author(s):  
Yin ◽  
Yang ◽  
Hong ◽  
Cai ◽  
Yu
Keyword(s):  
Big Data ◽  
Spectral Analysis ◽  
Spectral Data ◽  
Analysis Data ◽  
The Internet ◽  
Blockchain Technology ◽  
Big Data Technologies ◽  
Analysis System ◽  
Analysis Models ◽  
Big Data Technology

A portable smart spectrometer (PSS-1.0) and related systems have been designed and implemented to provide rapid on-site spectral analysis and lower the operator knowledge threshold for the application of spectrometry. The PSS-1.0 employs spectral analysis models downloaded from the spectral analysis system for offline spectral analysis and displays the results in the field. Users are incentivized to upload spectral analysis data to the Internet for storage by big data technologies, so that the spectral data can be reused easily. By employing blockchain technology it can be ensured that the data has not been tampered with, which can be used in monitoring and data transaction scenarios. The design of this spectrometer and related systems can be used for regulatory uses that require spectroscopy. Experimental results are presented in this paper, which prove that the design of the PSS-1.0 is feasible. The purpose of this paper is to design a civilian and non-operator knowledge threshold spectrometer and provide some ideas for better processing and utilization of spectral data.

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