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

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.

Download Full-text

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

Molecules ◽

10.3390/molecules23123378 ◽

2018 ◽

Vol 23 (12) ◽

pp. 3378 ◽

Cited By ~ 4

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.

Download Full-text

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

Journal of Chemical Research ◽

10.3184/174751917x14925986241016 ◽

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.

Download Full-text

Curdepsidones B–G, Six Depsidones with Anti-Inflammatory Activities from the Marine-Derived Fungus Curvularia sp. IFB-Z10

Marine Drugs ◽

10.3390/md17050266 ◽

2019 ◽

Vol 17 (5) ◽

pp. 266 ◽

Cited By ~ 3

Author(s):

Yi Ding ◽

Faliang An ◽

Xiaojing Zhu ◽

Haiyuan Yu ◽

Liling Hao ◽

...

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

2D Nmr ◽

Functional Theory ◽

Planar Structures ◽

Inflammatory Mechanism ◽

Ic50 Value ◽

Anti Inflammatory ◽

Dose Dependent ◽

Dependent Mechanism

Six new depsidones, curdepsidones B–G (1–6), were obtained from the marine-derived fungus Curvularia sp. IFB-Z10. Their planar structures were determined by comprehensive analysis of HRESIMS and 1D/2D-NMR data. The absolute configuration of curdepsidones B–C (1–2) were established by synergistic use of DFT/NMR (density functional theory/nuclear magnetic resonance) and TDDFT/ECD (time-dependent density functional theory/electronic circular dichroism) calculations. Partial isolated compounds were tested for their anti-inflammatory activities in Propionibacterium acnes-induced THP-1 cells. Curdepsidone C (2) displayed significant anti-inflammatory properties with an IC50 value of 7.47 ± 0.35 μM, and reduced the P. acnes-induced phosphorylation levels of JNK and ERK in a dose-dependent mechanism. The possible anti-inflammatory mechanism of 2 was also investigated by molecular docking.

Download Full-text

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.

Download Full-text

SIZE-DEPENDENCE OF INFRARED SPECTRA IN NIOBIUM CARBIDE NANOCRYSTALS

International Journal of Modern Physics C ◽

10.1142/s0129183112400013 ◽

2012 ◽

Vol 23 (08) ◽

pp. 1240001 ◽

Cited By ~ 2

Author(s):

V. ALVIN SHUBERT ◽

STEVEN P. LEWIS

Keyword(s):

Density Functional Theory ◽

Particle Size ◽

Density Functional ◽

Size Dependence ◽

Niobium Carbide ◽

Structural Features ◽

Particle Sizes ◽

Vibrational Modes ◽

Functional Theory ◽

Ir Spectroscopic

Niobium carbide nanocrystals of ~1:1 stoichiometry have recently been observed for particle sizes ranging from Nb4C4 to Nb50C50 . Infrared (IR) spectroscopic measurements show that a new band of IR vibrational modes appears with increasing particle size at Nb9C9 . Using density-functional theory, we show that the vibrational modes in the new band involve structural features present only in nanocrystals with three or more atomic layers in every direction. The Nb9C9 nanocrystal is right at this structural threshold.

Download Full-text

New Rod-Like H-Bonded Assembly Systems: Mesomorphic and Geometrical Aspects

Crystals ◽

10.3390/cryst10090795 ◽

2020 ◽

Vol 10 (9) ◽

pp. 795

Author(s):

Laila A. Al-Mutabagani ◽

Latifah Abdullah Alshabanah ◽

Hoda A. Ahmed ◽

Khulood A. Abu Al-Ola ◽

Mohamed Hagar

Keyword(s):

Density Functional ◽

Polarized Light ◽

Proton Donor ◽

Proton Acceptor ◽

Scanning Calorimetry ◽

Functional Theory ◽

Ft Ir ◽

Ir Spectroscopic ◽

Thermal Stability Of ◽

Bonded Complexes

Experimental and geometrical approaches of new systems of mesomorphic 1:1 supramolecular H-bonded complexes (SMHBCs) of five rings are discussed. The H-bonding between 4-alkoxyphenylimino benzoic acids (An, as proton acceptor) and 4-(4′–pyridylazophenyl) 4′′-alkoxybenzoates (Bm, as proton donor) were investigated. Mesomorphic behaviors were analyzed by differential scanning calorimetry (DSC) and mesophase textures were identified by polarized light microscopy (POM). H-bonded assembly was established by FT-IR spectroscopic measurements via Fermi band discussion. Thermal and theoretical factors were predicted for all synthesized complexes by density functional theory (DFT) predictions. The results revealed that all prepared complexes were monomorphic, with a broad range of smectic A phases with a high thermal stability of enantiotropic mesophase. Furthermore, DFT stimulations illustrated the experimental results in terms of the influence of the chain length either of the acid or the base component. Many parameters, such as the calculated stability, the dipole moment and the polarizability of the H-bonded complexes, illustrate how these parameters work together to enhance the smectic mesophases with the obtained stability and range.

Download Full-text

Discovery of New Secondary Metabolites by Epigenetic Regulation and NMR Comparison from the Plant Endophytic Fungus Monosporascus eutypoides

Molecules ◽

10.3390/molecules25184192 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4192

Author(s):

Zhe Guo ◽

Zhong-Mei Zou

Keyword(s):

Endophytic Fungus ◽

2D Nmr ◽

Chemical Diversity ◽

Ionization Mass ◽

Electrospray Ionization Mass Spectroscopy ◽

Planar Structures ◽

Ionization Mass Spectroscopy ◽

Epigenetic Manipulation ◽

New Compounds ◽

Mcf 7

Overexpression of the histone acetyltransferase and the 1H NMR spectroscopic experiments of the endophytic fungus Monosporascus eutypoides resulted in the isolation of two new compounds, monosporasols A (1) and B (2), and two known compounds, pestaloficin C (3) and arthrinone (4). Their planar structures and absolute configurations were determined by spectroscopic analysis including high resolution electrospray ionization mass spectroscopy (HRESIMS), one-dimensional (1D) and two-dimensional (2D) NMR, and calculated electronic circular dichroism data. Compounds 1–2 were screened in cytotoxic bioassays against HeLa, HCT-8, A549 and MCF-7 cells. Our work highlights the enormous potential of epigenetic manipulation along with the NMR comparison as an effective strategy for unlocking the chemical diversity encoded by fungal genomes.

Download Full-text

[(MeCN)Ni(CF3)3]1– and [Ni(CF3)4]2– : Foundations Towards the Development of Trifluoromethylations at Unsupported Nickel

10.26434/chemrxiv.12071673.v1 ◽

2020 ◽

Author(s):

Scott T. Shreiber ◽

Ida M. DiMucci ◽

Mikhail Khrizanforov ◽

Charles J. Titus ◽

Dennis Nordlund ◽

...

Keyword(s):

Density Functional Theory ◽

Cyclic Voltammetry ◽

Density Functional ◽

Functional Theory ◽

X Ray ◽

Iodonium Salt ◽

High Valent ◽

New Compounds ◽

X Ray Absorption ◽

Reduced State

The nickel anions [(MeCN)Ni(CF3)3]1– and [Ni(CF3)4]2– were prepared by formal addition of three and four equivalents of [AgCF3] to [(dme)NiBr2] in the presence of supporting [PPh4] counter-ion. Detailed insights into the electronic properties of these new compounds were obtained through the use of density functional theory (DFT) calculations, spectroscopy-oriented configuration interaction (SORCI) calculations, X-ray absorption spectroscopy, and cyclic voltammetry. The data collectively show that trifluoromethyl complexes of nickel, even in the most common oxidation state of nickel(II), are highly covalent systems whereby a hole is distributed on the trifluoromethyl ligands and surprisingly rendering the metal to a physically more reduced state. In the cases of [(MeCN)Ni(CF3)3]1– and [Ni(CF3)4]2–, these complexes are better described as physically d9 metal complexes. [(MeCN)Ni(CF3)3]1– is electrophilic and reacts with other nucleophiles like phenoxide to yield the unsupported [(PhO)Ni(CF3)3]2– salt, revealing the broader potential of [(MeCN)Ni(CF3)3]1– in the development of ligandless trifluoromethylations at nickel. Proof-in-principle experiments show that reaction of [(MeCN)Ni(CF3)3]1– with an aryl iodonium salt yields trifluoromethylated arene, presumably via a high valent, unsupported, and formally organonickel(IV) intermediate. Evidence for the feasibility of such intermediates is provided with the structurally characterized [Ni(CF3)4(SO4)][PPh4]2, which was derived through the two electron oxidation of [Ni(CF3)4]2–.

Download Full-text

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.12.188 ◽

2016 ◽

Vol 12 ◽

pp. 2012-2018 ◽

Cited By ~ 17

Author(s):

Peng Zhang ◽

Xiao-Ming Li ◽

Xin-Xin Mao ◽

Attila Mándi ◽

Tibor Kurtán ◽

...

Keyword(s):

Endophytic Fungus ◽

Density Functional ◽

Indole Derivative ◽

Marine Alga ◽

2D Nmr ◽

Paecilomyces Variotii ◽

Functional Theory ◽

Nmr Data ◽

Hepg2 Cell Lines ◽

C Nmr

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.

Download Full-text

Synthesis, optical and electrochemical study of bipolar heterocyclic systems, including 1,2,4-oxadiazole moiety

Organic Photonics and Photovoltaics ◽

10.1515/oph-2016-0004 ◽

2016 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

D. G. Selivanova ◽

O. A. Mayorova ◽

A. A. Gorbunov ◽

A. N. Vasyanin ◽

M. V. Dmitriev ◽

...

Keyword(s):

Excited States ◽

Density Functional ◽

Time Dependent ◽

Electrochemical Studies ◽

Absorption Data ◽

Functional Theory ◽

Conjugation Chain ◽

Td Dft ◽

Triplet Excited States ◽

New Compounds

AbstractTwo new 3,5-dihetarylsubstituted 1,2,4- oxadiazoles 8 a,b, including N-alkyl substituted carbazole and thiophene moieties, were synthesized as potential components of materials for organic electronics devices. Optical and electrochemical properties of all new compounds were investigated. On the basis of the experimental UV absorption data, the values of bandgap energies equal to 3.44 eV (8a) and 3.05 eV (8b) were determined. The values of their ionization potentials, HOMO levels (−5.62 eV for 8a, −5.46 eV – for 8b), as well as their electron affinity levels, LUMO levels (−2.2 eV for 8a, −2.4 eV – for 8b), were calculated from the results of electrochemical studies. The energy of the triplet excited states of 8 a,b was defined with the help of time-dependent density functional theory (TD-DFT), comprising 2.68 eV (8a) and 2.32 eV (8b), where the greatest value of this parameter was for the compound with a shorter conjugation chain.

Download Full-text