Structural Revision of Wentiquinone C and Related Congeners from Anthraquinones to Xanthones Using Chemical Derivatization and NMR Analysis

Wentiquinone C, which was previously isolated from the marine brown alga-derived endophytic fungus Aspergillus wentii EN-48, was found to be a potent antioxidant against α,α-diphenyl-picrylhydrazyl (DPPH) radical. The structure of wentiquinone C was originally assigned as an anthraquinone derivative (1,10-dihydroxy-3-(hydroxymethyl)-8-methoxydibenzo [b,e]oxepine-6,11-dione, 1) by 1D and 2D NMR experiments. However, the minor differences of the chemical shifts between xanthones and anthraquinones were queried, leading to the structure of 1 to be revised as a xanthone analog (8-hydroxy-6-(hydroxymethyl)-3-methoxy-9-oxo-9H-xanthene-1-carboxylic acid, 2) on the basis of a methylation and subsequent NMR measurements, and was confirmed by X-ray crystallographic analysis. The method established in this paper could be applied to the structural re-examination or revision for some of the reported seco-anthraquinone derivatives.

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Mono- and Dimeric Xanthones with Anti-Glioma and Anti-Inflammatory Activities from the Ascidian-Derived Fungus Diaporthe sp. SYSU-MS4722

Marine Drugs ◽

10.3390/md20010051 ◽

2022 ◽

Vol 20 (1) ◽

pp. 51

Author(s):

Senhua Chen ◽

Heng Guo ◽

Minghua Jiang ◽

Qilin Wu ◽

Jing Li ◽

...

Keyword(s):

High Resolution Mass Spectrometry ◽

2D Nmr ◽

Crystallographic Analysis ◽

Selective Cytotoxicity ◽

X Ray ◽

Planar Structures ◽

Spectroscopic Analyses ◽

Ic50 Values ◽

Anti Inflammatory ◽

Resolution Mass

Seven new xanthones, diaporthones A−G (1−7), together with 13 known analogues, including five mono- (8−14) and six dimeric xanthones (15−20), were obtained from the ascidian-derived fungus Diaporthe sp. SYSU-MS4722. Their planar structures were established by extensive spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HR-ESIMS). The absolute configurations of 1−7 were clearly identified by X-ray crystallographic analysis and calculation of the ECD Spectra. Compounds 15−20 showed significant anti-inflammatory activity with IC50 values between 6.3 and 8.0 μM. In addition, dimeric xanthones (15−20) showed selective cytotoxicity against T98G cell lines with IC50 values ranging from 19.5 to 78.0 μM.

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CHEMICAL CONSTITUENTS OF THE ETHYL ACETATE EXTRACT OF THE FRUIT BODIES OF PHELLINUS GILVUS

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/56/4a/12750 ◽

2018 ◽

Vol 56 (4A) ◽

pp. 246

Author(s):

Quang Ngoc Dang

Keyword(s):

Ethyl Acetate ◽

National Park ◽

Ethyl Acetate Extract ◽

Chemical Constituents ◽

2D Nmr ◽

Crystallographic Analysis ◽

X Ray ◽

Ergosterol Peroxide ◽

Cytotoxicity Activities ◽

Phellinus Gilvus

Five fungal secondary metabolites named 1,2,4,5-tetrachloro-3,6-dimethoxybenzene (1); ergosterol (2); ergosterol peroxide (3); (E)- 4-(3,4-dihydroxyphenyl)but-3-en-2-one (4) and [Bi-1,4-cyclohexandien-1-yl]-3,3’,6,6’-tetrone, 4, 4’-dihydroxyl-2,2’,5,5’-tetramethyl (5) were purified from ethyl acetate extract of the fruit bodies of Phellinus gilvus collected at Pu Mat national park, Nghe An province. Their structures were charaterized by 1D, 2D NMR and GC-MS spectroscopies. Especially, the structure of compound 1 was confirmed by X-ray crystallographic analysis. The antimicrobial and cytotoxicity activities of compounds 1 were also evaluated. This is the first report on the chemical constituents of Vietnamese Phellinus gilvus.

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Sterols from a Vietnamese Wood-Rotting Phellinus sp.

Zeitschrift für Naturforschung B ◽

10.1515/znb-2007-0224 ◽

2007 ◽

Vol 62 (2) ◽

pp. 289-292 ◽

Cited By ~ 2

Author(s):

Dang Ngoc Quang ◽

Dang Dinh Bach ◽

Yoshinori Asakawa

Keyword(s):

Nitric Oxide ◽

Absolute Configuration ◽

Methanolic Extract ◽

Uv Spectroscopy ◽

2D Nmr ◽

Crystallographic Analysis ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

X Ray ◽

Ir And Uv Spectroscopy

Phytochemical examination of the methanolic extract from fruit bodies of an unidentified Vietnamese Phellinus species led to the isolation of four compounds, one of which is a new steroid, 25-hydroxy-ergosta-7,24(28)-dien-3β -ol, named phellinol, together with senexonol, trametenolic acid B and ergosta-4,6,8(14),22-tetraen-3-one. Their structures were determined by 2D NMR, MS, IR and UV spectroscopy. In addition, the absolute configuration of senexonol was established by X-ray crystallographic analysis of its p-bromobenzoate derivative as 22(R)-hydroxy-4(S),14(S)- dimethyl-cholesta-8,24-dien-3-one. All compounds moderately suppressed the lipopolysaccharide (LPS)-induced production of nitric oxide (NO) in RAW 264.7 cells.

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Rhytidhyesters A – D, 4 New Chlorinated Cyclopentene Derivatives from the Endophytic Fungus Rhytidhysteron sp. BZM-9

Planta Medica ◽

10.1055/a-1429-3396 ◽

2021 ◽

Author(s):

Sha Zhang ◽

Wenxuan Wang ◽

Jianbin Tan ◽

Fenghua Kang ◽

Dekun Chen ◽

...

Keyword(s):

Endophytic Fungus ◽

Human Colon ◽

2D Nmr ◽

Crystallographic Analysis ◽

Cytotoxic Activities ◽

Human Colon Cancer ◽

X Ray ◽

Planar Structures ◽

Colon Cancer Cell Lines ◽

Ic50 Values

AbstractFour new chlorinated cyclopentene derivatives, rhytidhyesters A – D (1 – 4), were isolated from Rhytidhysteron sp. BZM-9, an endophytic fungus from Leptospermum brachyandrum. The planar structures of compounds 1 – 4 were mainly elucidated by 1D, 2D NMR, and HRESIMS data. Their absolute configurations were established by X-ray crystallographic analysis, quantum chemical 13C NMR, and electronic circular dichroism calculations. Compounds 1 and 2 are a pair of epimers. Moreover, all the isolated compounds were evaluated for cytotoxic activities against 3 human colon cancer cell lines (SW620, HT29, SW480) and antimicrobial activity against Staphylococcus aureus. All compounds exhibited weak to moderate antiproliferative activities with IC50 values ranging from 15.4 to 37.7 µM but were inactive against S. aureus.

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Novel Harziane Diterpenes from Deep-Sea Sediment Fungus Trichoderma sp. SCSIOW21 and Their Potential Anti-Inflammatory Effects

Marine Drugs ◽

10.3390/md19120689 ◽

2021 ◽

Vol 19 (12) ◽

pp. 689

Author(s):

Hongxu Li ◽

Xinyi Liu ◽

Xiaofan Li ◽

Zhangli Hu ◽

Liyan Wang

Keyword(s):

Deep Sea ◽

2D Nmr ◽

Crystallographic Analysis ◽

Spectroscopic Methods ◽

2D Nmr Spectroscopy ◽

Deep Sea Sediment ◽

X Ray ◽

Trichoderma Sp ◽

Anti Inflammatory ◽

Inflammatory Effect

Five undescribed harziane-type diterpene derivatives, namely harzianol K (1), harzianol L (4), harzianol M (5), harzianol N (6), harzianol O (7), along with two known compounds, hazianol J (2) and harzianol A (3) were isolated from the deep-sea sediment-derived fungus Trichoderma sp. SCSIOW21. The relative configurations were determined by meticulous spectroscopic methods including 1D, 2D NMR spectroscopy, and HR-ESI-MS. The absolute configurations were established by the ECD curve calculations and the X-ray crystallographic analysis. These compounds (1, and 4–7) contributed to increasing the diversity of the caged harziane type diterpenes with highly congested skeleton characteristics. Harzianol J (2) exhibited a weak anti-inflammatory effect with 81.8% NO inhibition at 100 µM.

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Quaternary structure of Limulus polyphemus hemocyanin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081747 ◽

1978 ◽

Vol 36 (2) ◽

pp. 176-177

Author(s):

T. Wichertjes ◽

E.J. Kwak ◽

E.F.J. Van Bruggen

Keyword(s):

Electron Microscopy ◽

Functional Properties ◽

Horseshoe Crab ◽

Temperature Jump ◽

Quaternary Structure ◽

Crystallographic Analysis ◽

Limulus Polyphemus ◽

Oxygen Binding ◽

X Ray ◽

Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

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Chemical shifts of the K X-ray absorption discontinuity of manganese in some compounds

Journal de Chimie Physique ◽

10.1051/jcp/1982790325 ◽

1982 ◽

Vol 79 ◽

pp. 325-329 ◽

Cited By ~ 8

Author(s):

M. Y. Apte ◽

C. Mandé ◽

J. P. Suchet

Keyword(s):

Chemical Shifts ◽

X Ray ◽

X Ray Absorption

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Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

MRS Proceedings ◽

10.1557/proc-713-jj2.2 ◽

2002 ◽

Vol 713 ◽

Cited By ~ 1

Author(s):

Roman V. Bogdanov ◽

Yuri F. Batrakov ◽

Elena V. Puchkova ◽

Andrey S. Sergeev ◽

Boris E. Burakov

Keyword(s):

Chemical Shifts ◽

Pyrochlore Structure ◽

Type Structure ◽

Waste Form ◽

X Ray ◽

Ceramic Waste ◽

Natural Minerals ◽

The Us ◽

Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

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