Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

A new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative, varioloid A (1), was isolated from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291. Its structure was elucidated on the basis of extensive analysis of 1D and 2D NMR data and the absolute configuration was determined by time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) calculations. A similar compound, whose planar structure was previously described but the relative and absolute configurations and 13C NMR data were not reported, was also identified and was tentatively named as varioloid B (2). Both compounds 1 and 2 exhibited cytotoxicity against A549, HCT116, and HepG2 cell lines, with IC50 values ranging from 2.6 to 8.2 µg/mL.

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Correction: Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.14.215 ◽

2018 ◽

Vol 14 ◽

pp. 2394-2395 ◽

Cited By ~ 1

Author(s):

Peng Zhang ◽

Xiao-Ming Li ◽

Xin-Xin Mao ◽

Attila Mándi ◽

Tibor Kurtán ◽

...

Keyword(s):

Endophytic Fungus ◽

Indole Derivative ◽

Marine Alga ◽

Paecilomyces Variotii

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Benchmark density functional theory calculations of 13 C NMR chemical shifts of the natural antimalarial compounds with a new basis set 3z‐S

International Journal of Quantum Chemistry ◽

10.1002/qua.26639 ◽

2021 ◽

Author(s):

Valentin A. Semenov ◽

Leonid B. Krivdin

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Chemical Shifts ◽

Density Functional Theory Calculations ◽

Basis Set ◽

Functional Theory ◽

Nmr Chemical Shifts ◽

C Nmr ◽

Antimalarial Compounds

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Hexaethyl-2,4-dicarba-nido-hexaborane(8), Deprotonation and Complexation Studied by NMR Spectroscopy and Density Functional Theory (DFT) Calculations

Zeitschrift für Naturforschung B ◽

10.1515/znb-2004-0609 ◽

2004 ◽

Vol 59 (6) ◽

pp. 685-691 ◽

Cited By ~ 8

Author(s):

Bernd Wrackmeyer ◽

Hans-Jörg Schanz

Keyword(s):

Density Functional Theory ◽

Nmr Spectroscopy ◽

Density Functional ◽

Chemical Shifts ◽

Coupling Constants ◽

Analogous Reaction ◽

Sandwich Complex ◽

Dft Methods ◽

Functional Theory ◽

Nmr Data

Deprotonation of hexaethyl-2,4-dicarba-nido-borane(8) 2 leads first to the hexaethyl-2,4-dicarbanido- borate(1−) 3, and further deprotonation, using BuLi/KOtBu, gives the hexaethyl-2,4-dicarbanido- hexaborate(2−) 4. The reaction of 3 with FeCl2 affords the commo-ferracarborane [Fe(Et6-2,4- C2B4H)2] 5, and the analogous reaction of 4 leads to the anionic sandwich complex [Fe(Et6-2,4- C2B4)2]2− 6 which can be protonated to give 5. The complex 5 contains two hydrido ligands, each bridging the iron and two boron atoms. Reactions were monitored and the products were characterised by 11B NMR spectroscopy in solution. The geometries of the carboranes, the borates (all unsubstituted and permethyl-substituted) and the iron complexes (all unsubstituted) were optimised by DFT methods [B3LYP/6-311+G(d,p) or B3LYP/6-31+G(d)], and the relevant NMR data [chemical shifts δ11B, δ13C, δ57Fe, and coupling constants 1J(13C,1H), 1J(11B,1H), 1J(57Fe,1H), 1J(57Fe,11B)] were calculated at the same level of theory.

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Flavonoids from Curcuma longa Leaves and their NMR Assignments

Natural Product Communications ◽

10.1177/1934578x1501000117 ◽

2015 ◽

Vol 10 (1) ◽

pp. 1934578X1501000 ◽

Cited By ~ 1

Author(s):

Chia-Ling Jiang ◽

Sheng-Fa Tsai ◽

Shoei-Sheng Lee

Keyword(s):

Nmr Assignments ◽

Soluble Fraction ◽

Curcuma Longa ◽

2D Nmr ◽

Etoh Extract ◽

Spectroscopic Analyses ◽

Nmr Data ◽

The Common ◽

Reported Data ◽

C Nmr

Chemical investigation of the n-BuOH-soluble fraction of the EtOH extract of the aerial part of Curcuma longa led to the isolation of 11 flavonol glycosides and one dihydroflavonol glucoside (1) via chromatography over Sephadex LH-20 and Lobar RP-18 columns. Although they are known, the 1H and 13C NMR data recorded in CD3OD rather than the common DMSO- d6 are doubly checked via extensive 2D NMR spectroscopic analyses, leading to some revisions of the reported data, especially for the glycon part.

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Hyperconjugation In Trialkylboranes Shown By Indirect Nuclear Spin-Spin Coupling Constants. Experimental Data And Density Functional Theory (Dft) Calculations

Zeitschrift für Naturforschung B ◽

10.1515/znb-2005-0304 ◽

2005 ◽

Vol 60 (3) ◽

pp. 259-264 ◽

Cited By ~ 29

Author(s):

Bernd Wrackmeyer ◽

Oleg L. Tok

Keyword(s):

Experimental Data ◽

Dft Calculations ◽

Density Functional ◽

Calculated Data ◽

Coupling Constants ◽

Spin Coupling ◽

Functional Theory ◽

Spin Coupling Constants ◽

Spin Spin Coupling ◽

C Nmr

Trimethylborane (1), triethylborane (2), 1,3-dimethyl-1-boracyclopentane (3), 1-methyl-1- boracyclohexane (4), 9-methyl- and 9-ethyl-9-borabicyclo[3.1.1]nonane [5(Me) and 5(Et)], and 1- boraadamantane (6) were studied by 11B and 13C NMR spectroscopy with respect to coupling constants 1J(13C,11B) and 1J(13C,13C). Results of DFT calculations at the B3LYP/6-311+g(d,p) level of theory show satisfactory agreement with the experimental data. Hyperconjugation arising from C-C σ bonds adjacent to the tricoordinate boron atom is indicated, in particular for 1-boraadamantane (6), by the optimised calculated structures, and by the experimental and calculated data 1J(13C,13C). The calculated magnitude of 1J(13C,1H) for carbon atoms adjacent to boron becomes significantly smaller if the optimised structures suggest hyperconjugative effects arising from these C-H bonds

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Dammarane and Ceanothane Triterpenes from Zizyphus glabrata

Zeitschrift für Naturforschung B ◽

10.1515/znb-2006-0118 ◽

2006 ◽

Vol 61 (1) ◽

pp. 87-92 ◽

Cited By ~ 8

Author(s):

Seru Ganapaty ◽

Pannakal S. Thomas ◽

Kancharalapalli V. Ramana ◽

Gloria Karagianis ◽

Peter G. Waterman

Keyword(s):

Bactericidal Activity ◽

Chemical Constituents ◽

2D Nmr ◽

First Report ◽

Nmr Data ◽

C Nmr ◽

Dammarane Glycoside

From the leaves of Zizyphus glabrata, a new dammarane-type triterpene, pseudojujubogenin -3-O- β -D-glucopyranoside, along with the known ceanothane triterpenes, granulosic acid, ceanothic acid and daucosterol were isolated. The structures of the compounds were fully characterized by detailed NMR investigations including 1H and 13C NMR, HSQC, COSY, HMBC and NOESY experiments. In addition, the dammarane glycoside was tested for its potential to inhibit various bacteria and was found to possess significant bactericidal activity. The 1H, 13C and full 2D-NMR data on granulosic acid has also been presented. This is the first report on the chemical constituents of the leaves of Z. glabrata.

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NMR spectroscopy of the phenyl derivative of germanium(IV) 5,10,15-tritolylcorrole

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424616500450 ◽

2016 ◽

Vol 20 (01n04) ◽

pp. 525-533

Author(s):

Giampaolo Ricciardi ◽

Daniel O. Cicero ◽

Sara Lentini ◽

Sara Nardis ◽

Roberto Paolesse ◽

...

Keyword(s):

Density Functional ◽

Chemical Shifts ◽

2D Nmr ◽

Functional Theory ◽

Phenyl Derivative ◽

Shielding Constants ◽

Shielding Tensor ◽

Experimental Values ◽

Molecular And Electronic Structure

A thoroughly structural characterization of (TTC)GePh (TTC [Formula: see text] 5,10,15-tritolylcorrole; Ph [Formula: see text] phenyl) in solution has been carried out through a combination of 2D NMR (1H-1H COSY, 1H-1H ROESY, 1H-[Formula: see text]C HSQC and 1H-[Formula: see text]C HMBC) experiments and density functional theory (DFT) calculations of the molecular and electronic structure and the shielding constants. The 1H and [Formula: see text]C chemical shifts computed at DFT-S12g and DFT-SAOP levels of theory nicely reproduce the experimental values, the agreement between theory and experiment being especially good for the DFT-S12g results. The calculations prove to be able to capture the fine details of the NMR spectra and to resolve some assignment ambiguities related to the inherent conformational flexibility of the macrocycle. The calculations also provide an explanation of the observed chemical shift trends in terms of diamagnetic and paramagnetic components of the shielding tensor.

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Solid State Structure and Absolute Configuration of Filifolinol Acetate

Natural Product Communications ◽

10.1177/1934578x1100600604 ◽

2011 ◽

Vol 6 (6) ◽

pp. 1934578X1100600

Author(s):

Marcelo A. Muñoz ◽

Alejandro Urzúa ◽

Javier Echeverría ◽

Brenda Modak ◽

Pedro Joseph-Nathan

Keyword(s):

Density Functional Theory ◽

Solid State ◽

Absolute Configuration ◽

Spectroscopic Data ◽

Density Functional ◽

Vibrational Circular Dichroism ◽

State Structure ◽

Functional Theory ◽

X Ray ◽

C Nmr

Careful reevaluation of the 1H and 13C NMR spectroscopic data of filifolinol acetate (4) led to the reassignment of the C-10 and C-11 signals, as well as the gem-dimethyl signals. Single crystal X-ray analysis provided an independent structural confirmation of 4, and comparison of the experimental vibrational circular dichroism spectrum with calculations performed using density functional theory provided the absolute configuration of this 3H-spiro-1-benzofuran-2,1′-cyclohexane and related molecules.

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Alteration of O-specific polysaccharide structure of symbiotically defective Mesorhizobium loti mutant 2213.1 derived from strain NZP2213.

Acta Biochimica Polonica ◽

10.18388/abp.2008_3216 ◽

2008 ◽

Vol 55 (1) ◽

pp. 191-200 ◽

Cited By ~ 10

Author(s):

Anna Turska-Szewczuk ◽

Hubert Pietras ◽

Wojciech Borucki ◽

Ryszard Russa

Keyword(s):

Wild Type Strain ◽

2D Nmr ◽

Chain Structure ◽

Wild Type ◽

Immunoblot Assay ◽

Mesorhizobium Loti ◽

Nmr Data ◽

Specific Polysaccharide ◽

C Nmr

Mesorhizobium loti mutant 2213.1 derived from the wild-type strain NZP2213 by Tn5 mutagenesis showed impaired effectiveness of symbiosis with the host plant Lotus corniculatus (Turska-Szewczuk et al., 2007 Microbiol Res, in press). The inability of lipopolysaccharide (LPS) isolated from the mutant 2213.1 strain or de-O-acetylated LPS of the parental cells to inactivate phage A1 particles implicated alterations in the LPS structure. The O-specific polysaccharide of the mutant was studied by chemical analyses along with (1)H and (13)C NMR spectroscopy, which clearly confirmed alterations in the O-chain structure. 2D NMR data showed that the mutant O-polysaccharide consists of a tetrasaccharide repeating unit containing non-substituted as well as O-acetylated or O-methylated 6-deoxytalopyranose residues. Additionally, an immunogold assay revealed a reduced number of gold particles on the mutant bacteroid cell surface, which could result from both a diminished amount of an O-antigenic determinant in mutant LPS and modifications of structural epitopes caused by alterations in O-acetylation or O-methylation of sugar residues. Western immunoblot assay of alkaline de-O-acetylated lipophilic M. loti NZP2213 LPS showed no reactivity with homologous serum indicating a role of O-acetyl groups in its O-specificity.

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