Anti-inflammatory dihydroxanthones from a Diaporthe species

2021

Abstract In a search for anti-inflammatory compounds from fungi inhibiting the promoter activity of the small chemokine CXCL10 (Interferon-inducible protein 10, IP-10) as a pro-inflammatory marker gene, the new dihydroxanthone methyl (1R, 2R)-1,2,8-trihydroxy-6-(hydroxymethyl)-9-oxo-2,9-dihydro-1H-xanthene-1-carboxylate (2) and the previously described dihydroxanthone AGI-B4 (1) were isolated from fermentations of a Diaporthe species. The structures of the compounds were elucidated by a combination of one- and two-dimensional NMR spectroscopy, mass spectrometry, and calculations using density functional theory (DFT). Compounds 1 and 2 inhibited the LPS/IFNγ induced CXCL10 promoter activity …

Marine Isonitriles and Their Related Compounds.

2016

Marine isonitriles represent the largest group of natural products carrying the remarkable isocyanide moiety. Together with marine isothiocyanates and formamides, which originate from the same biosynthetic pathways, they offer diverse biological activities and in spite of their exotic nature they may constitute potential lead structures for pharmaceutical development. Among other biological activities, several marine isonitriles show antimalarial, antitubercular, antifouling and antiplasmodial effects. In contrast to terrestrial isonitriles, which are mostly derived from α-amino acids, the vast majority of marine representatives are of terpenoid origin. An overview of all known marine isoni…

Total Synthesis of epi-Trichosetin.

2018

The natural 3-decalinoyltetramic acid epi-trichosetin was synthesized in ten steps starting from ( R)-(+)-citronellal using an intramolecular Diels-Alder reaction and a Lacey-Dieckmann cyclization as the key steps. The use of a 2-nitrobenzyl protecting group resulted in an efficient synthetic endgame. The natural product was obtained in 4.1% overall yield.

Structure determination and preliminary cytotoxicity researches of the compounds isolated from Rumex acetosella L. on leukemia cells

2017

ChemInform Abstract: Total Synthesis of (-)-Hymenosetin.

2016

Hymenosetin (I) and its N-methyl analogue are prepared in 11 and 8 steps, respectively, from citronellal employing an intramolecular Diels-Alder reaction as the key step.

Total Synthesis of (-)-Hymenosetin.

2015

The 3-decalinoyltetramic acid (−)-hymenosetin and its N-methyl analogue were prepared in 11 and 8 steps, respectively, from (+)-citronellal using an intramolecular Diels–Alder reaction as the key step. This method represents the first example for the synthesis of a 3-decalinoyltetramic acid with a free NH moiety. The stereochemistry of the title compound, an unnatural diastereomer, and of a decalin building block was studied in detail using circular dichroism spectroscopy in the IR and UV/VIS freqeuncy range. This allowed to determine the absolute configuration of the natural product and to plan the synthetic route.

Identification of NF-κB as Determinant of Posttraumatic Stress Disorder and Its Inhibition by the Chinese Herbal Remedy Free and Easy Wanderer

2017

Posttraumatic stress disorder (PTSD) is a mental disorder developing after exposure to traumatic events. Although psychotherapy reveals some therapeutic effectiveness, clinically sustainable cure is still uncertain. Some Chinese herbal formulae are reported to work well clinically against mental diseases in Asian countries, but the safety and their mode of action are still unclear. In this study, we investigated the mechanisms of Chinese remedy free and easy wanderer (FAEW) on PTSD. We used a reverse pharmacology approach combining clinical data to search for mechanisms of PTSD with subsequent in vitro verification and bioinformatics techniques as follows: (1) by analyzing microarray-based …

Cytotoxicity of Secondary Metabolites from Dracaena viridiflora Engl & Krause and their Semisynthetic Analogues

2017

The MeOH extract of Dracaena viridiflora was found to display significant cytotoxicity against some cancer cell lines. Systematic phytochemical investigation of this extract led to the isolation and structure elucidation of ten secondary metabolites including five spirostane (1-5) and one furostane (6) steroidal saponins. Furthermore, some acetylated spirostane analogues and three previously unreported derivatives with the 22,26-epoxycholesta-5,22-diene skeleton (15-17) were prepared from trillin (1), prosapogenin A of dioscin (2) and dioscin (4) by reaction with ZnCl 2/Ac 2O. Among the isolated and semisynthetic compounds, dioscin showed the most potent cytotoxicity against A549, Jurkat an…

CCDC 2081480: Experimental Crystal Structure Determination

2022

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