scholarly journals Analogs of the carotane antibiotic fulvoferruginin from submerged cultures of a Thai Marasmius sp.

2021 ◽  
Vol 17 ◽  
pp. 1385-1391
Author(s):  
Birthe Sandargo ◽  
Leon Kaysan ◽  
Rémy B Teponno ◽  
Christian Richter ◽  
Benjarong Thongbai ◽  
...  
Keyword(s):  
2D Nmr ◽  
Cd Spectroscopy ◽  
Cytotoxic Agent ◽  
Submerged Cultures ◽  
Northern Thailand ◽  
Derivatives Of

A recent find of a Marasmius species in Northern Thailand led to the isolation of five unprecedented derivatives of the carotane antibiotic fulvoferruginin (1), fulvoferruginins B–F (2–6). The structures of these sesquiterpenoids were elucidated using HRESIMS, 1D and 2D NMR, as well as CD spectroscopy. Assessing the bioactivity, fulvoferruginin emerged as a potent cytotoxic agent of potential pharmaceutical interest.

scholarly journals New Diterpenes with a Fused 6-5-6-6 Ring System Isolated from the Marine Sponge-Derived Fungus Trichoderma harzianum

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 480 ◽  
Author(s):  
Takeshi Yamada ◽  
Ayano Fujii ◽  
Takashi Kikuchi
Keyword(s):  
Mass Spectrometry ◽  
Marine Sponge ◽  
Trichoderma Harzianum ◽  
Fast Atom Bombardment ◽  
2D Nmr ◽  
Cd Spectroscopy ◽  
Ring System ◽  
Chemical Structures ◽  
Modified Mosher’S Method ◽  
Halichondria Okadai

New diterpenes, namely, trichodermanins F–H, with a fused 6-5-6-6 ring system were isolated from the fungus Trichoderma harzianum OUPS-111D-4 separated from a marine sponge Halichondria okadai. These chemical structures were elucidated by 1D and 2D NMR as well as high-resolution fast atom bombardment mass spectrometry (HRFABMS) spectral analyses. We established their absolute stereostructures by application of the modified Mosher’s method or circular dichroism (CD) spectroscopy. In addition, their cytotoxicities were assessed using several cancer cell lines, with 1 and 2 exhibiting modest activities.

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.

scholarly journals Anti-Vancomycin-resistant Enterococcus faecium and E. faecalis Activities of (-)-Gossypol and Derivatives from Thespesia garckeana

2015 ◽  
Vol 10 (4) ◽  
pp. 1934578X1501000
Author(s):  
Veronica M. Masila ◽  
Jacob O. Midiwo ◽  
Jin Zhang ◽  
Bonface M. Gisacho ◽  
Renee Munayi ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Candida Glabrata ◽  
2D Nmr ◽  
Stem Bark ◽  
Root Extract ◽  
Vancomycin Resistant Enterococcus ◽  
Reference Standard ◽  
Vancomycin Resistant ◽  
Derivatives Of ◽  
Modest Activity

The root extract of Thespesia garckeana yielded three known oxidatively coupled sesquiterpenoids, namely (-)-gossypol (1) and two of its derivatives (-)-6-methoxygossypol (2) and (+)-6,6′-dimethoxygossypol (3), and the stem bark afforded ( E)-docosyl-3-(3,4-dihydroxyphenyl) acrylate (4), stigmasterol (5) and betulinic acid (6). The structures of the isolated compounds were determined on the basis of full spectral data (1D and 2D NMR and HRMS) and comparison with literature values. Compound 1 showed potent antibacterial activity against vancomycin-resistant Enterococcus faecium (VRE) with IC50/MIC/MBC values of 1.71/4.82/19.31 μM, respectively, whereas the reference standard vancomycin was found to be inactive. The mono- and di-methoxylated derivatives of this compound, (-)-6-methoxygossypol (2) and (+)-6,6′-dimethoxygossypol (3), were less active with respective IC50/MIC/MBC values of 2.73/4.70/9.40 μM and 6.14/18.32/18.32 μM against this microbe. Compound 2 was more potent than 1 against the low level VRE strain with IC50/MIC/MBC values of 4.34/9.40/9.40 μM ( vs 5.23/19.31/19.31μM for 1). This compound also showed interesting activities against Candida glabrata with an IC50 value of 2.97 μM, but was less active against methicillin-resistant S. aureus (MRSA) exhibiting an IC50 value of 17.33 μM. Compound 1 demonstrated modest activity against the other microbes tested including C. glabrata, S. aureus and MRSA with IC50 values of 0.73, 9.15 and 8.99 μM, respectively.

scholarly journals New ent–Kaurane type Diterpene Glycoside, Pulicaroside-B, from Pulicaria Undulata L

2008 ◽  
Vol 3 (2) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Nasir Rasool ◽  
Viqar Uddin Ahmad ◽  
Naseem Shahzada ◽  
Muhammad A. Rashida ◽  
Aman Ullah ◽  
...  
Keyword(s):  
Spectral Data ◽  
Plant Extract ◽  
Soluble Fraction ◽  
2D Nmr ◽  
Spectroscopic Techniques ◽  
Spectral Evidence ◽  
Whole Plant ◽  
Derivatives Of ◽  
Related Compounds

Investigation of the n-butanol-soluble fraction of the whole plant extract of Pulicaria undulata yielded a new ent–kaurane type diterpene glycoside, pulicaroside-B (1), together with three known compounds, paniculoside-IV (2), roseoside (3), and corchoionol C (4). Compounds 3 and 4 are derivatives of α-ionol. The structures of the new and known compounds were elucidated by 1D- and 2D-NMR spectroscopic techniques, along with other spectral evidence, and by comparison of the spectral data with those of closely related compounds.

Unusual cyclization in the 11-hydroxy-1βH,5βH,6βH,7αH-guaian-6,12-olide series

1981 ◽  
Vol 46 (4) ◽  
pp. 941-946 ◽  
Author(s):  
Zdeněk Samek ◽  
Tomáš Vaněk ◽  
Miroslav Holub
Keyword(s):  
Steric Structure ◽  
Cd Spectroscopy ◽  
H Nmr ◽  
Derivatives Of

Derivatives of the keto triester II, particularly the ether VI, were investigated by 1H-NMR and CD spectroscopy. Formation of the ether VI and comparison of its parameters with those of other described compounds prove that the originally suggested steric structure of acetylisomontanolide (VII) is correct.

Triazene derivatives of (1,x)-diazacycloalkanes — Part IX. Synthesis and characterization of a series of 1,4-di[2-aryl-1-diazenyl]-2,6-dimethylpiperazines

2010 ◽  
Vol 88 (4) ◽  
pp. 344-351 ◽  
Author(s):  
Naomi Hunter ◽  
Keith Vaughan
Keyword(s):  
Diazonium Salt ◽  
Mass Measurement ◽  
2D Nmr ◽  
Piperazine Ring ◽  
Ir And Nmr Spectroscopy ◽  
Methylene Groups ◽  
Type 3 ◽  
Derivatives Of

A series of 1,4-di-[2-aryl-1-diazenyl]-2,6-dimethylpiperazines (5a–5l), have been synthesized by the reaction of 2,6-dimethylpiperazine with 2 equiv. of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C6 of the piperazine ring in the bis-triazene 5 creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 5 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in most cases. The assignment of the proton and carbon signals in the 1,4-di-[2-aryl-1-diazenyl]-2,6-dimethylpiperazines has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of type 3.

scholarly journals Pt(iv) derivatives of cisplatin and oxaliplatin with phenylbutyrate axial ligands are potent cytotoxic agents that act by several mechanisms of action

2016 ◽  
Vol 7 (3) ◽  
pp. 2381-2391 ◽  
Author(s):  
Raji Raveendran ◽  
Jeremy Phillip Braude ◽  
Ezequiel Wexselblatt ◽  
Vojtech Novohradsky ◽  
Olga Stuchlikova ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Mechanisms Of Action ◽  
Cytotoxic Agents ◽  
Cytotoxic Agent ◽  
Axial Ligands ◽  
Cellular Pathways ◽  
Derivatives Of

The Pt(iv) derivative of cisplatin,ctc-[Pt(NH3)2(PhB)2Cl2], is a p53 independent very potent cytotoxic agent that kills cancer cells by triggering various cellular pathways.

scholarly journals A New Megastigmane Glycoside, Phoenixoside A, from Phoenix Dactylifera

2012 ◽  
Vol 7 (1) ◽  
pp. 1934578X1200700
Author(s):  
Sumbul Azmat ◽  
Aqib Zahoor ◽  
Rehana Ifzal ◽  
Viqar Uddin Ahmad ◽  
Faryal Vali Mohammed
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Soluble Fraction ◽  
2D Nmr ◽  
Phoenix Dactylifera ◽  
Cd Spectroscopy ◽  
2D Nmr Spectroscopy ◽  
Resolution Mass

A new megastigmane glycoside, phoenixoside A (1), has been isolated from the n-butanol - soluble fraction of seeds of Phoenix dactylifera. The structure was characterized as (6S,7Z,9R)-hydroxy-3-oxo-ionol-9- O-β-D-glucopyranosyl-(1″→6′)-β-D–glucopyranoside on the basis of 1D and 2D NMR spectroscopy, high-resolution mass spectrometry, and CD spectroscopy.

scholarly journals Hemi-Synthesis of Chiral Imine, Benzimidazole and Benzodiazepines from Essential Oil of Ammodaucus leucotrichus subsp. leucotrichus

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 975 ◽  
Author(s):  
Farid Chebrouk ◽  
Khodir Madani ◽  
Brahim Cherfaoui ◽  
Leila Boukenna ◽  
Mónica Válega ◽  
...  
Keyword(s):  
Essential Oil ◽  
Hplc Analysis ◽  
Reaction Medium ◽  
2D Nmr ◽  
Chiral Hplc ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reaction Proceeds ◽  
Derivatives Of

The hemi-synthesis of chiral imine, benzimidazole and benzodiazepine structures is reported by the condensation of (S)-(−)-perillaldehyde, the major phytochemical of Ammodaucus leucotrichus subsp. leucotrichus essential oil, with different amine derivatives of 2,3-diaminomaleonitrile, o-phenylenediamine and 3-[(2-aminoaryl)amino]dimedone. The reaction proceeds in situ at ambient temperature without prior isolation of the natural (S)-(−)-perillaldehyde. Final products precipitate in the ethanolic reaction medium. 2D NMR and single-crystal X-ray diffraction studies were used to unequivocally characterize the structures in solution and in the solid state, respectively. Chiral HPLC analysis confirms the formation of unique enantiomers and diastereomeric mixtures.

scholarly journals Syntheses and In Vitro Biological Activity of Some Derivatives of C-9154 Antibiotic

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Isaac Asusheyi Bello ◽  
George Iloegbulam Ndukwe ◽  
Joseph Olorunju Amupitan ◽  
Rachael Gbekele Ayo ◽  
Francis Oluwole Shode
Keyword(s):  
Biological Activity ◽  
Minimum Inhibitory Concentration ◽  
Functional Group ◽  
Inhibitory Concentration ◽  
2D Nmr ◽  
Esterification Reaction ◽  
New Antibiotics ◽  
Derivatives Of ◽  
Better Than

In our continued attempts at designing new antibiotics based on the structure of the C-9154 antibiotic, to simultaneously improve activity and lower toxicity, an analogue to the C-9154 antibiotic and six derivatives of this analogue were synthesized. The approach was to significantly reduce the polarity of the synthesized analogue in the derivatives to achieve increased permeability across cell membranes by conversion of the highly polar carboxylic group to an ester functional group. The compounds were synthesized using a two-step reaction which involved an additional reaction between benzyl amine and maleic anhydride and then conversion of the terminal carboxylic acid functional group to an ester functional group using a thionyl chloride mediated esterification reaction. The compounds were fully characterized using Infrared, GC-MS, and 1D and 2D NMR experiments. The in vitro biological activity of the compounds showed that the derivatives were more active than the analogues as was anticipated with minimum inhibitory concentration in the range 0.625–5 μg/mL. The analogue had minimum inhibitory concentration in the range 2.5–10 μg/mL. These values are significantly better than that obtained for the original C-9154 antibiotic which had activity in the range 10–>100 μg/mL.

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