Search results for "Leukemia L5178"

Differential in vitro Anti-HIV Activity of Natural Lignans

1990

Abstract Two naturally occurring lignanolides, isolated from the tropical climbing shrub Ipomoea cairica, (-)-arctigen in and (-)-trachelogen in , were found to inhibit strongly replication of human immunodeficiency virus type 1 (HIV-1; strain HTLV-III B) in vitro. At a concentration of 0.5 (μм , (-)-arctigenin and (-)-trachelogenin inhibited the expression of HIV-1 proteins p 17 and p24 by 80 -90 % and 60 -70 % , respectively. The reverse transcriptase activity in the cul­ture fluids was reduced by 80 -90 % when the cells (HTLV-III B/H 9) were cultivated in the presence of 0.5 μм (-)-arctigen in or 1 μм (-)-trachelogenin . At the same concentrations, the formation of syncytia in the HTLV-I…

Lactones from the Sponge-Derived Fungus Talaromyces rugulosus.

2017

The marine-derived fungus Talaromyces rugulosus isolated from the Mediterranean sponge Axinella cannabina and cultured on solid rice medium yielded seventeen lactone derivatives including five butenolides (1–5), seven (3S)-resorcylide derivatives (6–12), two butenolide-resorcylide dimers (13 and 14), and three dihydroisocoumarins (15–17). Among them, fourteen compounds (1–3, 6–16) are new natural products. The structures of the isolated compounds were elucidated by 1D and 2D NMR (Nuclear Magnetic Resonance) spectroscopy as well as by ESI-HRMS (ElectroSpray Ionization-High Resolution Mass Spectrometry). TDDFT-ECD (Time-Dependent Density Functional Theory-Electronic Circular Dichroism) calcul…

Physicochemical and functional characterization of the polymerization process of the Geodia cydonium lectin

1985

The extracellularly localized, galactose-specific lectin from the sponge Geodia cydonium binds at one class of sites, 40 mol Ca2+/mol lectin with an association constant (Ka) of 0.3 X 10(6)M-1. Stoichiometric calculations reveal that in the extracellular milieu 22 mol Ca2+ (maximum) are complexed per mol lectin. Binding of Ca2+ to the lectin increases its apparent Mr from 44000 to 56000 (electrophoretic determination) or from 36500 to 53500 (high-pressure liquid gel chromatographical determination); the s20, w increases from 4.3 S to 4.5 S if Ca2+ is added to the lectin. In the presence of Ca2+ the lectin undergoes a conformational change perhaps by expanding the carbohydrate side chains wh…

Cell cycle-dependent alterations of the two types of ribonucleases H in L5178y cells.

1980

A New Tetrahydrofuran Derivative from the Endophytic Fungus Chaetomium sp. Isolated from Otanthus maritimus

2009

1 A hitherto unidentified endophytic strain of the genus Chaetomium, isolated from the medicinal plant Otanthus maritimus, yielded a new tetrahydrofuran derivative, aureonitolic acid (), along with 5 known natural products, 2 - 6. The structure of 1 was determined by extensive spectroscopic analysis and comparison with reported data. Extracts of the fungus, grown either in liquid culture or on solid rice media, exhibited considerable cytotoxic activity when tested in vitro against L5178Y mouse lymphoma cells. Compounds 2 and 6 showed significant growth inhibition against L5178Y cells with EC50 values of 7.0 and 2.7 μg/mL, respectively, whereas 1 was inactive

Cytostatic Activity of Aeroplysinin-1 against Lymphoma and Epithelioma Cells

1989

(±)-Aeroplysinin-1, an optically active 1.2-dihydroarene-1.2-diol. was isolated from the marine sponges Verongia aerophoba (+-isomer) and lanthella ardis (--isomer). For the experiments presented we used the +-isomer from Verongia aerophoba. Here we describe the hitherto unknown biological and pharmacological property of this compound to display pronounced anticancer activity against L5178y mouse lymphoma cells (ED50: 0.5 μm). Friend erythroleukemia cells (ED50: 0.7μm) , human mamma carcinoma cells (ED50: 0.3μm) and human colon carcinoma cells (ED50: 3.0 μm) in vitro. Furthermore, aeroplysinin caused a preferential inhibition of [3H]thymidine (dThd) incorporation rates in L5178y mouse lymph…

Synergistic effect of peplomycin in combination with bleomycin on L5178y mouse lymphoma cells in vivo.

1984

Studying the treatment of NMRI mice with ip injections of bleomycin (BLM) for 5 days we found an approximate LD50 of 35 mg/kg; the toxicity of peplomycin (PEP) was slightly higher (LD50: approximately 25 mg/kg). The effect of the two drugs on growth of L5178y mouse lymphoma cells in NMRI mice was examined. BLM alone caused at a concentration of 2.5 mg/kg an almost complete inhibition of tumor cell growth; the same effect was determined with 1 mg PEP/kg. At these concentrations the drugs caused an increase of the survival time of 110% (BLM) or 104% (PEP). Given in combination, one-sixth of the optimal doses yielded an 100% increase of the median survival time. These results indicate a signif…

Bioactive metabolites from the endophytic fungus Ampelomyces sp. isolated from the medicinal plant Urospermum picroides

2007

Extracts of cultures grown in liquid or on solid rice media of the fungal endophyte Ampelomyces sp. isolated from the medicinal plant Urospermum picroides exhibited considerable cytotoxic activity when tested in vitro against L5178Y cells. Chromatographic separation yielded 14 natural products that were unequivocally identified based on their 1H and 13C NMR as well as mass spectra and comparison with previously published data. Six compounds (2, 4, 5, 7, 9 and 11) were natural products. Both fungal extracts differed considerably in their secondary metabolites. The extract obtained from liquid cultures afforded a pyrone (2) and sulfated anthraquinones (7 and 9) along with the known compounds …

Joziknipholones A and B: The First Dimeric Phenylanthraquinones, from the Roots ofBulbine frutescens

2007

From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-co…

Energy requirement and kinetics of transport of poly(A)-free histone mRNA compared to poly(A)-rich mRNA from isolated L-cell nuclei.

1989

ATP-promoted efflux of poly(A)-rich RNA from isolated nuclei of prelabeled mouse lymphoma L5178y cells has an activation energy of 51.5 kJ/mol, similar to that found for the nuclear envelope nucleoside triphosphatase (48.1 kJ/mol) assumed to be involved in mediating nucleocytoplasmic transport of at least some RNA. Here we show that efflux of two specific poly(A)-rich mRNAs (actin and beta-tubulin) from isolated L-cell nuclei is almost totally dependent on the presence of ATP, while efflux of poly(A)-free histone mRNA (H4, H2B, and H1) also occurs to a marked extent in the absence of this nucleotide. Measurements of temperature dependence of transport rate revealed an activation energy of 5…