Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
Knipholone (1) and knipholone anthrone (2), isolated from the Ethiopian medicinal plant Kniphofia foliosa Hochst. are two phenyl anthraquinone derivatives, a compound class known for biological activity. In the present study, we describe the activity of both 1 and 2 in several biological assays including cytotoxicity against four human cell lines (Jurkat, HEK293, SH-SY5Y and HT-29), antiplasmodial activity against Plasmodium falciparum 3D7 strain, anthelmintic activity against the model organism Caenorhabditis elegans, antibacterial activity against Aliivibrio fischeri and Mycobacterium tuberculosis and anti-HIV-1 activity in peripheral blood mononuclear cells (PBMCs) infected with HIV-1c. In parallel, we investigated the stability of knipholone (2) in solution and in culture media. Compound 1 displays strong cytotoxicity against Jurkat, HEK293 and SH-SY5Y cells with growth inhibition ranging from approximately 62–95% when added to cells at 50 μM, whereas KA (2) exhibits weak to strong activity with 26, 48 and 70% inhibition of cell growth, respectively. Both 1 and 2 possess significant antiplasmodial activity against Plasmodium falciparum 3D7 strain with IC50 values of 1.9 and 0.7 μM, respectively. These results complement previously reported data on the cytotoxicity and antiplasmodial activity of 1 and 2. Furthermore, compound 2 showed HIV-1c replication inhibition (growth inhibition higher than 60% at tested concentrations 0.5, 5, 15 and 50 μg/ml and an EC50 value of 4.3 μM) associated with cytotoxicity against uninfected PBMCs. The stability study based on preincubation, HPLC and APCI-MS (atmospheric-pressure chemical ionization mass spectrometry) analysis indicates that compound 2 is unstable in culture media and readily oxidizes to form compound 1. Therefore, the biological activity attributed to 2 might be influenced by its degradation products in media including 1 and other possible dimers. Hence, bioactivity results previously reported from this compound should be taken with caution and checked if they differ from those of its degradation products. To the best of our knowledge, this is the first report on the anti-HIV activity and stability analysis of compound 2.
Publikation
Al-Fatimi, M.; Ali, N. A. A.; Kilian, N.; Franke, K.; Arnold, N.; Kuhnt, C.; Schmidt, J.; Lindequist, U.;Ethnobotany, chemical constituents and biological activities of the flowers of Hydnora abyssinica A.Br. (Hydnoraceae)Pharmazie71222-226(2016)DOI: 10.1691/ph.2016.5808
Hydnora abyssinica A.Br. (Hydnoraceae), a holoparasitic herb, is for the first time recorded for Abyan governorate of South Yemen. Flowers of this species were studied for their ethnobotanical, biological and chemical properties for the first time. In South Yemen, they are traditionally used as wild food and to cure stomach diseases, gastric ulcer and cancer. Phytochemical analysis of the extracts showed the presence of terpenes, tannins, phenols, and flavonoids. The volatile components of the air-dried powdered flowers were identified using a static headspace GC/MS analysis as acetic acid, ethyl acetate, sabinene, α-terpinene, (+)-D-limonene and γ-terpinene. These volatile compounds that characterize the odor and taste of the flowers were detected for the first time in a species of the family Hydnoraceae. The flowers were extracted by n-hexane, dichlormethane, ethyl acetate, ethanol, methanol and water. With exception of the water extract all extracts demonstrated activities against Gram-positive bacteria as well as remarkable radical scavenging activities in DPPH assay. Ethyl acetate, methanol and water extracts exhibited good antifungal activities. The cytotoxic activity of the extracts against FL cells, measured in neutral red assay, was only weak (IC50 > 500 μg /mL). The results justify the traditional use of the flowers of Hydnora abyssinica in South Yemen.