Search

Phytochemical investigation of the whole plants of Vernonia gratiosa Hance. led in the isolation and identification of two new stigmastane-type steroidal glucosides (1–2), namely vernogratiosides A (1), and B (2). Their chemical structures were fully elucidated based on 1 D/2D NMR spectroscopic, HR-ESI-MS data analyses, and by producing derivatives by chemical reactions. The binding potential of the isolated compounds to replicase protein − main protease of SARS-CoV-2 were examined using the molecular docking simulations. Our results show that the isolated steroidal glucosides (1–2) bind to the substrate‐binding site of SARS-CoV-2 main protease with binding affinities of −7.2 and −7.6 kcal/mol, respectively, as well as binding abilities equivalent to N3 inhibitor that has already been reported (–7.5 kcal/mol). [ABSTRACT FROM AUTHOR]

Using various chromatographic methods, five abietane-type diterpenes were isolated from the branches of Glyptostrobus pensilis for the first time. The chemical structures of the isolates were identified by modern spectroscopic techniques, including 1H and 13C nuclear magnetic resonance spectroscopy and by comparison with the literature. In addition, the binding potential of the isolated compounds to replicase protein, SARS-CoV-2 main protease and papain-like protease, were examined using molecular docking studies. In silico results suggested that G. pensilis as well as abietane-types diterpenes are potential candidates for the prevention and treatment of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Chemical investigation of a peanut-associated fungal strain Aspergillus niger IMBC-NMTP01 resulted in isolation and identification of 14 secondary metabolites, including two new, epi-aspergillusol (1) and aspernigin (3), and 12 known compounds: pyrophen (2), 2-(hydroxyimino)-3-(4-hydroxyphenyl)propanoic acid (4), aspergillusol A (5), rubrofusarin B (6), nigerasperone A (7), fonsecin (8), TMC-256C1 (9), pyranonigrin A (10), orlandin (11), nigerasperone C (12), asperpyrone A (13), and 5-(hydroxymethyl)-2-furancarboxylic acid (14). Compounds 9, 12-14 showed cytotoxicity toward all six human cancer cell lines, including HepG2, KB, HL-60, MCF-7, SK-Mel2, and LNCaP, with IC50 values ranging from 8.4 to 84.5 µM, compounds 3-5 were cytotoxic against five cancer cell lines except HepG2, whereas 1 exhibited cytotoxicity toward HepG2, KB, and MCF-7 cells. All of the compounds, except 2 and 13, inhibited NO overproduction in LPS-induced RAW264.7 cells. In addition, all of the compounds displayed antimicrobial effects against Enterococcus faecalis, whereas 13 compounds, except 10, significantly inhibited the growth of the yeast Candida albicans. [ABSTRACT FROM AUTHOR]

Chemical investigation of the marine-derived endophytic fungus Ascomycota sp. VK12 resulted in isolation and identification of a new compound, (3R)-(3′,5′-dihydroxyphenyl)butan-2-one (1) and five known ones: AGI-7 (2), sescandelin (3), sescandelin-B (4), 4-hydroxybenzaldehyde (5), and hydroxysydonic acid (6). The absolute configuration of 1 was determined by time-dependent density functional theory electronic circular dichroism, specific optical rotation, and NMR calculations. Compounds 1 and 2 showed cytotoxicity towards HepG2, MCF-7, and SK-Mel2 carcinoma cells, with IC50 values ranging from 48.6 to 96.5 µM. Compounds 1, 2, 4–6 displayed NO inhibitory effects in LPS-stimulated BV2 cells, with IC50 values in a range from 24.2 to 76.5 µM. Compound 2 further inhibited PGE2 overproduction, with an IC50 value of 25.3 µM. The inhibitory effects of 2 towards NO and PGE2 overproduction were found to have a close relationship with its suppression of iNOS and COX-2 protein expression, respectively. [ABSTRACT FROM AUTHOR]

Vietnamese traditional medicine has utilised the roots of Polygala arillata Buch.-Ham. ex D. Don to treat acute arthritis, rheumatism, pain, and as a tonic ingredient. In this study, phytochemical analysis of the roots of P. arillata resulted in the isolation of one novel compound, named polygarinolide A ( 1 ), along with six known compounds ( 2 - 7 ). High-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) and one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy were among the spectroscopic techniques used to identify their structures. Additionally, the absolute configuration of compound 1 was determined through ECD calculation. The NO inhibitory activity of purified substances was evaluated. Interestingly, compound 2 exhibited inhibitory activity on NO production in LPS-stimulated RAW264.7 cells (IC 50 = 25.37 μM). Moreover, interactions and binding mechanisms of the most active chemical with cyclooxygenase-2 inhibitor (COX-2) and nitric oxide synthase (iNOS) proteins were investigated by molecular docking simulations. Our findings add to our understanding of the secondary metabolites generated by P. arillata and provide a sound scientific basis for future research into the plant's potential anti-inflammatory properties.

A new [7.7]paracyclophane ( 1 ), together with eight known compounds ( 2 - 9 ), were isolated from a MeOH extract of the sea snail Planaxis sulcatus (Born, 1780). Their structures were elucidated by HR-ESI-MS and NMR techniques as well as comparison with those reported in literatures. The absolute configuration of metabolite 1 was determined using ECD spectroscopy. Among nine compounds, 1 exhibited significant cytotoxicity toward all eight cancer cells tested with IC 50 values between 1.81 and 3.80 µg/mL.[Figure: see text].