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Nguyen Tan Thanh Nguyen Ngoc Tuan Ping-Chung Kuo Doan Manh Dung Doan Lan Phuong Dinh Thi Truong Giang 《Natural product research》2018,32(20):2392-2397
A new tirucallane-type triterpenoid igniarine (1), and four known compounds meshimakobnol A (2), meshimakobnol B (3), ergosterol (4) and ergosterol peroxide (5), were purified from the methanol extracts of the fruiting bodies of Phellinus igniarius (DC. ex Fr.) Quél. The structure of 1 was elucidated using a combination of 1D and 2D NMR techniques and HR-ESI-MS analyses. In addition, the isolated compounds were examined for their cytotoxicity against several tumour cell lines and part of the tested compounds demonstrated weak cytotoxicity. 相似文献
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IR Spectrum and Structure of Protonated Monosilanol: Dative Bonding between Water and the Silylium Ion 下载免费PDF全文
M. Sc. Martin Andreas Robert George Dr. Nguyen Xuan Truong Dipl.‐Phys. Marco Savoca Prof. Dr. Otto Dopfer 《Angewandte Chemie (International ed. in English)》2018,57(11):2919-2923
We report the spectroscopic characterization of protonated monosilanol (SiH3OH2+) isolated in the gas phase, thus providing the first experimental determination of the structure and bonding of a member of the elusive silanol family. The SiH3OH2+ ion is generated in a silane/water plasma expansion, and its structure is derived from the IR photodissociation (IRPD) spectrum of its Ar cluster measured in a tandem mass spectrometer. The chemical bonding in SiH3OH2+ is analyzed by density functional theory (DFT) calculations, providing detailed insight into the nature of the dative H3Si+‐OH2 bond. Comparison with protonated methanol illustrates the differences in bonding between carbon and silicon, which are mainly related to their different electronegativity and the different energy of the vacant valence pz orbital of SiH3+ and CH3+. 相似文献
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Due to a significant discrepancy between theoretical calculations and experimental excitation data, the position of the low-lying triplet state of water has been much debated in recent years. We now report that the corresponding transition (≈ 4.0 eV) can be observed also in emission upon charge neutralization in γ-irradiated ordinary and heavy ices and also by photosensitization from the mercury 3P1 or 3P0 state. The observed radiative decay is characterized by an emission λmax at 380–385 nm. 相似文献
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Thanh-Hung Do Thuc-Huy Duong Huy Truong Nguyen Thi-Hien Nguyen Jirapast Sichaem Chuong Hoang Nguyen Huu-Hung Nguyen Nguyen Phuoc Long 《Molecules (Basel, Switzerland)》2022,27(9)
Lichen-derived monoaromatic compounds are bioactive compounds, associated with various pharmacological properties: antioxidant, antifungal, antiviral, cytotoxicity, and enzyme inhibition. However, little is known about data regarding alpha-glucosidase inhibition and antimicrobial activity. Very few compounds were reported to have these activities. In this paper, a series of monoaromatic compounds from a lichen source were isolated and structurally elucidated. They are 3,5-dihydroxybenzoic acid (1), 3,5-dihydroxybenzoate methyl (2), 3,5-dihydroxy-4-methylbenzoic acid (3), 3,5-dihydroxy-4-methoxylbenzoic acid (4), 3-hydroxyorcinol (5), atranol (6), and methyl hematommate (7). To obtain more derivatives, available compounds from the previous reports such as methyl β-orsellinate (8), methyl orsellinate (9), and D-montagnetol (10) were selected for bromination. Electrophilic bromination was applied to 8–10 using NaBr/H2O2 reagents to yield products methyl 5-bromo-β-orsellinate (8a), methyl 3,5-dibromo-orsellinate (9a), 3-bromo-D-montagnetol (10a), and 3,5-dibromo-D-montagnetol (10b). Compounds were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. Compound 4 showed stronger alpha-glucosidase inhibition than others with an IC50 value of 24.0 µg/mL. Synthetic compound 9a exhibited remarkable activity against Staphylococcus aureus with a MIC value of 4 µg/mL. Molecular docking studies were performed to confirm the consistency between in vitro and in silico studies. 相似文献
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