scholarly journals Isolation and Characterization of Two New Antimicrobial Acids from Quercus incana (Bluejack Oak)

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Rizwana Sarwar ◽  
Umar Farooq ◽  
Sadia Naz ◽  
Nadia Riaz ◽  
Syed Majid Bukhari ◽  
...  
Keyword(s):  
Ethyl Acetate Fraction ◽  
Structural Formula ◽  
2D Nmr ◽  
Spectroscopic Technique ◽  
Pentanoic Acid ◽  
One Dimensional ◽  
Isolation And Characterization ◽  
Nmr Techniques ◽  
New Compounds

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.

scholarly journals Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

2021 ◽  
Vol 17 ◽  
pp. 2390-2398
Author(s):  
Emmanuel Tope Oluwabusola ◽  
Olusoji O Adebisi ◽  
Fernando Reyes ◽  
Kojo S Acquah ◽  
Mercedes De La Cruz ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Antimicrobial Properties ◽  
2D Nmr ◽  
Culture Broth ◽  
Moderate Activity ◽  
North Central ◽  
Isolation And Characterization ◽  
Antimicrobial Evaluation ◽  
New Compounds

Five new phenolic siderophores 1–5 were isolated from the organic extract of a culture broth in a modified SGG medium of Pseudomonas sp. UIAU-6B, obtained from sediments collected from the Oyun river in North Central Nigeria. The structure of the new compounds, pseudomonin A–C (1–3) and pseudomobactin A and B (4 and 5) isolated alongside two known compounds, pseudomonine (6) and salicylic acid (7), were elucidated based on high-resolution mass spectrometry, 1D and 2D NMR analyses. The absolute configuration of the threonine residue in compounds 1–5 was determined by Marfey analysis. The antimicrobial evaluation of compound 4 exhibited the most potent activity against vancomycin-sensitive Enterococcus faecium VS144754, followed by 3 and 5, with MIC values ranging from 8 to 32 µg/mL. Compounds 2 and 3 exhibited moderate activity against Mycobacterium tuberculosis H37Rv, with MIC values of 7.8 and 15.6 µg/mL, respectively. Plausible biosynthetic hypotheses toward the new compounds 1–5 were proposed.

scholarly journals Pentacyclic Triterpenoids from Maytenus cuzcoina

2017 ◽  
Vol 12 (5) ◽  
pp. 1934578X1701200
Author(s):  
Carolina P. Reyes ◽  
Ignacio A. Jiménez ◽  
Isabel L. Bazzocchi
Keyword(s):  
2D Nmr ◽  
Bark Extract ◽  
Phytochemical Analysis ◽  
Spectroscopic Methods ◽  
Root Bark ◽  
Pentacyclic Triterpenoids ◽  
Isolation And Characterization ◽  
Nmr Techniques ◽  
First Time

Phytochemical analysis of the root bark extract of Maytenus cuzcoina (Celastraceae) led to the isolation and characterization of sixteen triterpenoids with a 6/6/6/6/6 pentacyclic system, including the new 22α-hydroxy-29-methoxy-3β-tetradecanoate-olean-12-ene, and 3β,24β-epoxy-29-methoxy-2α,3α,6α-trihydroxy- D:A-friedelane that is reported for the first time as a natural product. This is the first instance of the isolation of a tetradecanoate triterpene ester from a Celastraceae species. The structures were elucidated on the basis of spectrometric and spectroscopic methods, including 1D and 2D NMR techniques.

scholarly journals Isolation of the Tetrapeptide Apicidins G, H and I from the Fungus Fusarium semitectum

2014 ◽  
Vol 9 (2) ◽  
pp. 1934578X1400900
Author(s):  
Suciati ◽  
Mary J. Garson
Keyword(s):  
2D Nmr ◽  
Isolation And Characterization ◽  
Fusarium Semitectum ◽  
New Compounds

This study reports the isolation and characterization of three new tetrapeptides, apicidins G (1), H (2) and I (3), along with the known apicidin (4), apicidin A (5), apicidin C (6), diketopiperazine 7, equisetin (8) and 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (9). The structures of the new compounds were deduced by 2D NMR spectroscopic and MS data.

Structural elucidation of two new compounds from Artemisia ordosica and their antioxidative activity

2019 ◽  
Vol 74 (10) ◽  
pp. 699-702
Author(s):  
Guo-Hua Wu ◽  
Qing-Hu Wang ◽  
Xiang He ◽  
Wen-Qiang Bao ◽  
Bi-Li-Ge-Tu Pa
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging ◽  
2D Nmr ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Artemisia Ordosica ◽  
One Dimensional ◽  
Scavenging Capacity ◽  
Nmr Techniques ◽  
New Compounds

AbstractTwo new compounds, namely, arteordosin A (1) and arteordosin B (2), were isolated from the CHCl3 extract of Artemisia ordosica. This is the first report on the structure elucidation of arteordosin A (1) and arteordosin B (2) based on spectroscopic methods including electrospray ionization mass spectrometry, one-dimensional (1D) nuclear magnetic resonance spectroscopy (NMR) and 2D NMR techniques. Antioxidant activities of the compounds were measured for their radical scavenging capacity using 2,2-diphenyl-1-picrylhydrazyl. Compound 1 (IC50 of 1.01 mg mL−1) showed antioxidant activity similar to the standard reference ascorbic acid (IC50 of 0.98 mg mL−1) and is more active than compound 2 (IC50 of 1.87 mg mL−1). In conclusion, arteordosin A (1) and arteordosin B (2) may be used as potential antihyperlipidemic agent in routine clinical practice.

Rarely Occurring Natural Products Isolated from Vincetoxicum stocksii

2019 ◽  
Vol 41 (4) ◽  
pp. 695-695
Author(s):  
Saima Khan Saima Khan ◽  
Muhammad Imran Tousif Muhammad Imran Tousif ◽  
Naheed Raiz Naheed Raiz ◽  
Mamona Nazir Mamona Nazir ◽  
Mahreen Mukhtar Mahreen Mukhtar ◽  
...  
Keyword(s):  
Natural Products ◽  
Methanol Extract ◽  
High Resolution Mass Spectrometry ◽  
Ethyl Acetate Fraction ◽  
2D Nmr ◽  
Ethyl Carbamate ◽  
Carbamic Acid ◽  
Nmr Analysis ◽  
Nmr Techniques ◽  
Resolution Mass

Silica gel column chromatography of the ethyl acetate fraction of methanol extract of Vincetoxicum stocksii resulted in the separation of three new rarely occurring natural products; [4-(4-(methoxycarbonyl)benzyl)phenyl] carbamic acid (1), bis[di-p-phenylmethane]ethyl carbamate (2), methyl 2-hydroxy-3-(2-hydroxy-5-(3-methylbut-2-enyl)phenyl)-2-(4-hydroxyphenyl) propanoate, stocksiloate(3), along with five known compounds; 1-(4-hydroxy-3-methoxyphenyl)-1,2,3,-propanetriol (4), feruloyl-6-O-β-D-glucopyranoside (5), 4-hydroxy-3,5-dimethoxybenzoic acid (6), apocynin (7) and vincetomine (8). The structures of compounds 1 and 2 were established with help of 1D, 2D-NMR techniques and high resolution mass spectrometry, whereas, compound 3 could only be characterized tentatively by 1D, 2D-NMR techniques. Compounds 1 is new compound while 2 is synthetically known but never been reported from natural source. The known compounds were identified due to 1D NMR analysis and in comparison with the literature values. Compounds 1-3 were found inactive in an anti-urease assay.

scholarly journals Isolation and Characterization of Crotosparsamide, a New Cyclic Nonapeptide from Croton sparsiflorus

2010 ◽  
Vol 5 (12) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Rashad Mehmood ◽  
Abdul Malik
Keyword(s):  
Spectroscopic Data ◽  
2D Nmr ◽  
Spectral Studies ◽  
Isolation And Characterization ◽  
First Time

Crotosparsamide (1), a new cyclic nonapeptide, has been isolated from the n-butanol soluble sub-fraction of Croton sparsiflorus along with p-hydroxy methylcinnamate and kaempferol, which are reported for the first time from this species. Their structures were determined by chemical and spectral studies including ESIMS, and 1D and 2D NMR spectroscopic data.

scholarly journals Unusual Polyhydroxylated Steroids from the Starfish Anthenoides laevigatus, Collected off the Coastal Waters of Vietnam

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1440
Author(s):  
Alla A. Kicha ◽  
Dinh T. Ha ◽  
Timofey V. Malyarenko ◽  
Anatoly I. Kalinovsky ◽  
Roman S. Popov ◽  
...  
Keyword(s):  
Coastal Waters ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Cytotoxic Effects ◽  
One Dimensional ◽  
The Common ◽  
Polyhydroxylated Steroids ◽  
New Compounds ◽  
Ht 29 ◽  
Inhibit Cell Proliferation

Four new polyhydroxylated steroids 1–4 were isolated along with two previously known related steroids 5 and 6 from the methanolic extract of the starfish Anthenoides laevigatus collected off the coastal waters of Vietnam. Structures of new compounds were substantially elucidated by one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy and HRESIMS techniques. Heptaol 1 and hexaol 2 contain the common 5α-cholestane skeleton, while hexaol 3 and heptaol 4 have the rare among starfish steroid compounds 5β-cholestane skeleton. Compounds 1, 5, and 6 do not show cytotoxic effects against normal JB6 Cl41 and cancer HT-29 and MDA-MB-231 cells, however they inhibit cell proliferation and colony formation of cancer HT-29 and MDA-MB-231 cells.

scholarly journals Biflavonoids from the Unripe Fruits of Clusia Paralicola and their Antioxidant Activity

2012 ◽  
Vol 7 (12) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Rafaela Ferreira Oliveira ◽  
Celso Amorim Camara ◽  
Maria de Fátima Agra ◽  
Tania Maria Sarmento Silva
Keyword(s):  
Antioxidant Activity ◽  
Linoleic Acid ◽  
Spectral Data ◽  
2D Nmr ◽  
Cd Spectra ◽  
Total Extract ◽  
Isolation And Characterization ◽  
Β Carotene ◽  
Unripe Fruits

Investigation of the green fruits of Clusia paralicola (Clusiaceae) led to the isolation and characterization of two 3,8″-biflavonoids, 2R, 3S, 2″R, 3″R-GB1-7″- O-β-glucoside (1) and 2R, 3S, 2″R, 3,8″-binaringenin-7″-O-β-glucoside (2), together with four known compounds: β-sitosterol, stigmasterol, β-amyrin, and epicatechin. The structures were established from the IR, LC-ESI-MS and NMR spectral data, including 2D-NMR experiments. The absolute configurations of 1 and 2 were determined by CD spectra. The total extract and the biflavonoids demonstrated significant antioxidant activity in DPPH, ABTS, and β-carotene/linoleic acid tests.

scholarly journals Synthesis and Characterization of Low-Cost Cresol-Based Benzoxazine Resins as Potential Binders in Abrasive Composites

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2995
Author(s):  
Artur Jamrozik ◽  
Mateusz Barczewski ◽  
Grzegorz Framski ◽  
Daniel Baranowski ◽  
Paulina Jakubowska ◽  
...  
Keyword(s):  
Low Cost ◽  
2D Nmr ◽  
Additional Analysis ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Voc Emission ◽  
Chemical Structures ◽  
Oxazine Ring ◽  
Nmr Techniques

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.

scholarly journals Secondary metabolites of Phlebopus species from Northern Thailand

2020 ◽  
Vol 19 (12) ◽  
pp. 1525-1536
Author(s):  
Boontiya Chuankid ◽  
Hedda Schrey ◽  
Benjarong Thongbai ◽  
Olivier Raspé ◽  
Norbert Arnold ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
2D Nmr ◽  
Cytotoxic Activities ◽  
Tumor Cell Lines ◽  
Submerged Cultures ◽  
Esi Ms ◽  
Spectroscopic Analyses ◽  
New Compounds ◽  
Comprehensive Characterization

AbstractSubmerged cultures of the edible mushrooms Phlebopus portentosus and Phlebopus spongiosus were screened for their secondary metabolites by HPLC-UV/Vis and HR-LC-ESI-MS. Two new compounds, 9′-hydroxyphenyl pulvinone (1), containing an unusual pulvinone structure, and phlebopyron (2), together with the seven known pigments, atromentic acid (3), xerocomic acid (4), variegatic acid (5), methyl atromentate (6), methyl isoxerocomate (7), methyl variegatate (8), and variegatorubin (9) were isolated from the cultures. Their structures were assigned on the basis of extensive 1D/2D NMR spectroscopic analyses, as well as HR-ESI-MS, and HR-ESI-MS/MS measurements. Furthermore, the isolated compounds were evaluated for their antimicrobial and cytotoxic properties. 9′-hydroxyphenyl pulvinone (1), xerocomic acid (4), and methyl variegatate (8) exhibited weak to moderate cytotoxic activities against several tumor cell lines. The present paper provides a comprehensive characterization of pigments from the class of pulvinic acids that are present in the basidiomes of many edible bolete species.

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