scholarly journals Benzophenone Derivatives from an Algal-Endophytic Isolate of Penicillium chrysogenum and Their Cytotoxicity

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3378 ◽  
Author(s):  
Dong-Lin Zhao ◽  
Xiao-Long Yuan ◽  
Yong-Mei Du ◽  
Zhong-Feng Zhang ◽  
Peng Zhang
Keyword(s):  
Penicillium Chrysogenum ◽  
Density Functional ◽  
2D Nmr ◽  
Coupling Constants ◽  
Grateloupia Turuturu ◽  
Functional Theory ◽  
Drug Candidates ◽  
Ic50 Values ◽  
Marine Algal ◽  
New Compounds

Chromatographic separation of a marine algal-derived endophytic fungus Penicillium chrysogenum AD-1540, which was isolated from the inner tissue of the marine red alga Grateloupia turuturu, yielded two new benzophenone derivatives, chryxanthones A and B (compounds 1 and 2, respectively). Their structures were undoubtedly determined by comprehensive analysis of spectroscopic data (1D/2D NMR and HRESIMS). The relative and absolute configurations were assigned by analysis of the coupling constants and time-dependent density functional theory (TDDFT) calculations of their electronic circular dichroism (ECD) spectra, respectively. Both compounds possessed an unusual dihydropyran ring (ring D) fused to an aromatic ring, rather than the commonly occurring prenyl moiety, and a plausible biosynthetic pathway was postulated. The cytotoxicities of compounds 1 and 2 were evaluated against six human cell lines, and both of the compounds demonstrated weak to moderate cytotoxicities with IC50 values ranging from 20.4 to 46.4 μM. These new compounds further demonstrate the potential of marine-derived fungi as an untapped source of pharmaceutical components with unique properties that could be developed as drug candidates.

scholarly journals Cytotoxic Furanoditerpenes from the Sponge Spongia tubulifera Collected in the Mexican Caribbean

Marine Drugs ◽  
2019 ◽  
Vol 17 (7) ◽  
pp. 416 ◽  
Author(s):  
Dawrin Pech-Puch ◽  
Jaime Rodríguez ◽  
Bastien Cautain ◽  
Carlos Alfredo Sandoval-Castro ◽  
Carlos Jiménez
Keyword(s):  
Density Functional ◽  
2D Nmr ◽  
Functional Theory ◽  
Planar Structures ◽  
Mexican Caribbean ◽  
Tumour Cell Lines ◽  
New Compounds ◽  
Ir Spectroscopic ◽  
Human Tumour Cell Lines ◽  
Spongian Diterpene

Two new spongian furanoditerpenes, 3β-hydroxyspongia-13(16),14-dien-2-one (1) and 19-dehydroxy-spongian diterpene 17 (2), along with five known terpenes, the spongian furanoditerpenes 9-nor-3-hydroxyspongia-3,13(16),14-trien-2-one (3), 3β,19 dihydroxyspongia-13(16),14-dien-2-one (epispongiadiol) (4) and spongian diterpene 17 (5), the furanoditerpene ambliol C (6), and the sesterterpene scalarin (7), were isolated from the methanolic extract of the sponge Spongia tubulifera, collected in the Mexican Caribbean. The planar structures of the new compounds were elucidated by 1D/2D NMR and IR spectroscopic analysis, high resolution electrospray mass spectrometry (HRESIMS), and comparison of their spectral data with those reported in the literature. Absolute configurations were determined by comparison of the experimental electronic circular dichroism (ECD) spectrum with those calculated by time-dependent density functional theory (TDDFT). Compounds 1, 4, and 6 displayed weak cytotoxic activity against different human tumour cell lines.

The structures of xenorine A–C from the entomopathogenic bacterium Xenorhabdus indica

2017 ◽  
Vol 41 (5) ◽  
pp. 262-265
Author(s):  
Lie-Feng Ma ◽  
Hao-Ying Qian ◽  
Yang Zheng ◽  
Wei-Wei Pang ◽  
Yuan-Yuan Li ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
2D Nmr ◽  
Immunosuppressive Activity ◽  
Functional Theory ◽  
Chemical Structures ◽  
Synthetic Product ◽  
New Compounds

Three new compounds, xenorine A-C, along with six known compounds were isolated from the cultured broth of Xenorhabdus indica. The chemical structures of these compounds were elucidated mainly by analysis of 1D and 2D NMR and MS data. The major metabolites were dioxopiperazines. In addition, 5,6,11,11a-tetrahydro-1 H-imidazo[1′,5′:1,6]pyrido[3,4- b]indole-1,3(2 H)-dione, previously described as synthetic product, was isolated as a natural product. The absolute configuration was determined using quantum chemical time-dependent density functional theory calculations. The six known compounds showed weak in vitro immunosuppressive activity towards concanavalin-A- and lipopolysaccharide -induced proliferation of mice splenocytes.

Assessing the Calculation of Exchange Coupling Constants and Spin Crossover Gaps Using the Approximate Projection Model to Improve Density Function Calculations

2019 ◽  
Author(s):  
Xianghai Sheng ◽  
Lee Thompson ◽  
Hrant Hratchian
Keyword(s):  
Density Functional Theory ◽  
Exchange Coupling ◽  
Density Functional ◽  
Spin Crossover ◽  
Coupling Constants ◽  
Spin Projection ◽  
Coupling Constant ◽  
Projection Model ◽  
Functional Theory

This work evaluates the quality of exchange coupling constant and spin crossover gap calculations using density functional theory corrected by the Approximate Projection model. Results show that improvements using the Approximate Projection model range from modest to significant. This study demonstrates that, at least for the class of systems examined here, spin-projection generally improves the quality of density functional theory calculations of J-coupling constants and spin crossover gaps. Furthermore, it is shown that spin-projection can be important for both geometry optimization and energy evaluations. The Approximate Project model provides an affordable and practical approach for effectively correcting spin-contamination errors in molecular exchange coupling constant and spin crossover gap calculations.

scholarly journals Fusarins G–L with Inhibition of NO in RAW264.7 from Marine-Derived Fungus Fusarium solani 7227

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 305
Author(s):  
Guangyuan Luo ◽  
Li Zheng ◽  
Qilin Wu ◽  
Senhua Chen ◽  
Jing Li ◽  
...  
Keyword(s):  
Fusarium Solani ◽  
2D Nmr ◽  
Inflammatory Activity ◽  
Raw264.7 Cells ◽  
Spectroscopic Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Structure Activity ◽  
Ic50 Values ◽  
New Compounds

Six new fusarin derivatives, fusarins G–L (1–6), together with five known compounds (5–11) were isolated from the marine-derived fungus Fusarium solani 7227. The structures of the new compounds were elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS, ECD, and ORC) and X-ray crystallography. Compounds 5–11 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide, with IC50 values ranging from 3.6 to 32.2 μM. The structure–activity relationships of the fusarins are discussed herein.

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

2004 ◽  
Vol 59 (6) ◽  
pp. 685-691 ◽  
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.

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

2005 ◽  
Vol 60 (3) ◽  
pp. 259-264 ◽  
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

Indirect Nuclear Spin-Spin Coupling Constants 1J(17O,11B). First Observation And Calculation Using Density Functional Theory (Dft)

2006 ◽  
Vol 61 (8) ◽  
pp. 949-955 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Oleg L. Tok
Keyword(s):  
Density Functional ◽  
Reasonable Agreement ◽  
Bond Angle ◽  
Calculated Data ◽  
Molecular Structures ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Functional Theory ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

Coupling constants 1J(17O,11B) of borates, borane adducts and boranes with boron-oxygen bonds have been calculated on the basis of optimised molecular structures using the B3LYP/6-311+G(d,p) level of theory. This indicates that such coupling constants can be of either sign and that their magnitudes can be rather small. Since both 11B and 17O are quadrupole nuclei, it is therefore difficult to measure representative data. In the cases of trimethoxyborane and tetraethyldiboroxanes, it proved possible to obtain experimental data 1J(17O,11B) (22 and 18 Hz) by measurement of 17O NMR spectra at high temperature (120 °C and 160 °C) respectively. The magnitude of these coupling constants is in reasonable agreement with calculated data. In the case of the diboroxane, this points towards a bond angle B-O-B more close to 180◦ than to 140°

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

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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