scholarly journals CHARACTERIZATION OF CYTOCHALASINS AND STEROIDS FROM THE FRUITING BODIES OF Daldinia concentrica (BOLTON FR. CES. & DE NOT) IN VIETNAM

2018 ◽  
Vol 56 (4A) ◽  
pp. 83
Author(s):  
Thang Dinh Tran

ABSTRACT-HCTN_14[11]-cytochalasa-6(12), 13-diene- 1, 21-dione-7, 18, 19- trihydroxy-16,18-dimethyl-10-phenyl-(7S*, 13E, 16S*, 18S*, 19R*) (1), [11]-cytochalasa-6(12),13-dien-1,21-dion-7,18-dihydroxy-16,18-dimethyl-10-phenyl -(7S*, 13E, 16S*, 18R*) (2), ergosterol (3) and ergosterol peroxit (4) were isolated from the methanolic extract of the fruit body of Daldinia concentrica. The structures of these compounds were elucidated using a combination of UV, IR, 1D and 2D NMR techniques (1H-, 13C-NMR, COSY, HSQC and HMBC) and MS analyses.

2001 ◽  
Vol 56 (7-8) ◽  
pp. 521-525 ◽  
Author(s):  
Denata Kasaj ◽  
Liselotte Krenn ◽  
Sonja Prinz ◽  
Antje Hüfner ◽  
Shi Shan Yuc ◽  
...  

The detailed investigation of a methanolic extract of aerial parts of Achillea pannonica SCHEELE. within a chemotaxonomic study led to the isolation of 6 flavonoid glycosides. Besides rutin, apigenin-7-O-glucopyranoside, luteolin-7-O-glucopyranoside, apigenin-7-O-rutinoside and acacetin-7-O-rutinoside, an unusual flavondiglucoside was isolated. Its structure was established by UV, 1HNMR and 13C NMR spectroscopic methods including 2D-NMR techniques and ESI-MS as luteolin-7,4′-O-β-diglucoside. This substance is reported for the first time in the genus Achillea. Chemotaxonomic aspects are discussed briefly


2009 ◽  
Vol 64 (11-12) ◽  
pp. 790-792 ◽  
Author(s):  
Jin-Wen Shen ◽  
Bing-Ji Ma ◽  
Wen Li ◽  
Hai-You Yu ◽  
Ting-Ting Wu ◽  
...  

The methanolic extract of the fruiting bodies of the mushroom Armillariella tabescens was found to show antifungal activity against Gibberella zeae. The active compound was isolated from the fruiting bodies of A. tabescens by bioassay-guided fractionation of the extract and identifi ed as armillarisin B. Armillarisin B eventually corresponds to 2-hydroxy-2- phenylpropanediamide and its structure was confi rmed on the basis of spectroscopic studies including 2D NMR experiments.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2995
Author(s):  
Artur Jamrozik ◽  
Mateusz Barczewski ◽  
Grzegorz Framski ◽  
Daniel Baranowski ◽  
Paulina Jakubowska ◽  
...  

A series of cresol-based benzoxazines were synthesized for potential application as a polymer matrix in abrasive composites. The chemical structures of the obtained benzoxazine resins were investigated in detail using Fourier transform infrared spectroscopy (FTIR) and hydrogen-1 as well as carbon-13 nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR) with an additional analysis using two-dimensional NMR techniques (2D NMR 1H-1H COSY, 1H-13C gHSQC and gHMBC). Structural analysis confirmed the presence of vibrations of -O-C-N- at ~950 cm−1 wavenumber, characteristic for an oxazine ring. The thermal properties of benzoxazine monomers were examined using differential scanning calorimetry (DSC) analysis. The polymerization enthalpy varied from 143.2 J/g to 287.8 J/g. Thermal stability of cresol-based benzoxazines was determined using thermogravimetry (TGA) analysis with additional analysis of the amount of volatile organic compounds (VOC) emitted from the synthesized benzoxazines during their crosslinking by static headspace coupled with gas chromatography technique (HS-GC). The amount of residual mass significantly differed between all synthesized polybenzoxazines in the range from 8.4% to 21.2%. The total VOC emission for benzoxazines decreased by 46–77% in reference to a conventional phenolic binder. The efficiency of abrasive composites with the benzoxazine matrix was evaluated based on abrasion tests. Performed analyses confirmed successful synthesis and proper chemical structure of cresol-based benzoxazines. All the experiments indicated that benzoxazines based on different cresol isomers significantly differ from each other. Good thermal performance and stability of the abrasive composites with the polybenzoxazine matrix and significantly lower VOC emission allow us to state that benzoxazines can be a promising and valuable alternative to the phenolics and a new path for the development of modern, eco-friendly abrasives.


2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Rizwana Sarwar ◽  
Umar Farooq ◽  
Sadia Naz ◽  
Nadia Riaz ◽  
Syed Majid Bukhari ◽  
...  

Two new compounds [1-2] were purified from ethyl acetate fraction of Quercus incana. The structure of these compounds is mainly established by using advanced spectroscopic technique such as UV, IR, one-dimensional (ID) and two-dimensional (2D) NMR techniques, and EI mass. The structural formula was deduced to be 4-hydroxydecanoic acid [1] and 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2]. Both isolated compounds were tested for their antimicrobial potential and showed promising antifungal activity against Aspergillus niger and Aspergillus flavus.


2010 ◽  
Vol 75 (10) ◽  
pp. 3214-3223 ◽  
Author(s):  
Ananya Majumdar ◽  
Yan Sun ◽  
Meha Shah ◽  
Caren L. Freel Meyers

2017 ◽  
Vol 55 (5) ◽  
pp. 535
Author(s):  
Nguyen Ngoc Tuan ◽  
Tran Thi Kim Anh ◽  
Ping-Chung Kuo ◽  
Tran Dinh Thang

A hopane triterpenoid (11b, 22-dihydroxyhopane) was isolated from the methanol extract of the mycelium of Isaria japonica in Vietnam. The structure of this compound was elucidated using a combination of 1D and 2D NMR techniques (1H-, 13C-NMR, COSY, HSQC and HMBC). In the study, we reported the comprehensive 1H- and 13C-NMR spectral data of 11b, 22-dihydroxyhopane for the first time.


2020 ◽  
Vol 31 (1) ◽  
pp. 5-8
Author(s):  
Gloria Ihuoma Ndukwe ◽  
Amarachi Oluah ◽  
Godswill Kuta Fekarurhobo

AbstractChromatographic separation of methanolic extract of Baphia nitida heartwood gave two crystalline solids characterized as 3,9-dimethoxy-6aR,11aR-dihydro-6H-benzofuro(3,2-C)[1]benzopyran (also known as homopterocarpin) with molecular formula C17H16O4 (1.57% yield) and 2,4-dimethoxybenzaldehyde C9H10O3 (2.27% yield). Each of the isolated compounds showed a single spot on developed thin layer chromatographic plate under ultra-violet light (254 nm) and spray reagent (10% sulfuric acid in methanol solution). Structural elucidation was achieved using Fourier transform infrared (FT-IR) spectroscopy, one and two-dimension nuclear magnetic resonance (NMR) techniques. Distortionless enhancement by polarization transfer-edited-heteronuclear single quantum coherence (DEPT-ed-HSQC) was also a useful tool that aided the characterization of the two secondary metabolites isolated from Baphia nitida heartwood.


Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 478-482 ◽  
Author(s):  
Sara A. Lisboa ◽  
Dmitry V. Evtuguin ◽  
Carlos Pascoal Neto

Abstract The amount of non-cellulosic glucans in Eucalyptus globulus wood (approx. 4.5%) was assessed by extraction of sawdust with a 0.5 M NaOH solution at 90–120°C and the structural features were elucidated in a glucan-enriched polysaccharide fraction isolated by hot water extraction (120°C, 2 h). Isolated soluble glucans were characterized by wet chemistry methods and a set of 1D and 2D NMR techniques. The major proportion of glucans consisted of amylose (20%) and amylopectin (80%), although a small proportion of β-(1→3)-glucan (<0.2% on wood weight) was also detected. Although glucans are easily removed in the initial phase of kraft pulping, notable amounts were found in unbleached pulp and it was supposed that in the final stage of kraft pulping a fraction of α-glucan is precipitated onto the fiber surface and contributes to the pulp yield.


1991 ◽  
Vol 29 (13) ◽  
pp. S38-S44 ◽  
Author(s):  
Daniel Nanz ◽  
Wolfgang Von Philipsborn ◽  
Urs E. Bucher ◽  
Luigi M. Venanzi

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