Quinine

Hahn, Fred E.

doi:10.1007/978-3-642-46407-2_17

Cited by 3 publications

(2 citation statements)

References 24 publications

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“…Design Principle. The design principle that we have used for the construction of a prototype (i.e., 1 ) incorporates three structural elements that are found in the naturally occurring, pore-forming antibiotic amphotericin B . Specifically, it in-cludes a long and rigid hydrophobic (sterol) unit, an amphiphilic (polyamine) chain that can extend across this unit, and a zwitterionic (ammonium sulfate) headgroup, i.e., analogues of amphotericin B's heptaene, polyol, and carboxyl/mycosamine moieties, respectively .…”

Section: Resultsmentioning

confidence: 99%

Sterol−Polyamine Conjugates as Synthetic Ionophores

et al. 1998

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A design principle has been devised for the construction of sterol−polyamine conjugates that function as synthetic ionophores. For feasibility studies, a prototype (1) was synthesized from 3β-hydroxybisnor-5-cholenic acid via sequential activation of its carboxylic acid moiety, condensation with spermine, and sulfation of the 3β-hydroxyl group. Closely related analogues were also prepared in which the terminal amine group was acetylated (2), the 3β-hydroxyl group was left unsulfated (3), and each of the two remaining secondary amines was replaced with oxygen atoms (4). Incorporation of each conjugate into egg phosphatidylglycerol-based vesicles showed that 1 functions as an ionophore by discharging a pH difference across the vesicle membrane, but that 2, 3, and 4 do not. A kinetic analysis of the ionophoric activity of 1 has provided evidence that the majority of the conjugate exists as membrane-bound monomer and that dimers are the active species that are responsible for ion transport. Comparative experiments have also shown that 1 exhibits greater activity in negatively charged phospholipid membranes relative to ones that are electrically neutral. The implications of these findings, with regard to the design of new classes of antibacterial agents, are briefly discussed.

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Section: Resultsmentioning

confidence: 99%

Sterol−Polyamine Conjugates as Synthetic Ionophores

et al. 1998

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“…5-13 Transmission electron micrograph images of Henneguya sp., treated samples by strong fevers (Hahn 1980). In general, quinine acts as a protoplasmic poison and, furthermore, quinine is suggested to inhibit the synthesis of nucleic acids via intercalation with the DNA.…”

Section: Discussionmentioning

confidence: 99%

Effects of orally administered chemotherapeutics (quinine, salinomycin) against Henneguya sp. Thelohán, 1892 (Myxozoa: Myxobolidae), a gill parasite in the tapir fish Gnathonemus petersii Günther, 1862 (Teleostei)

Dohle

Schmahl

Raether³

et al. 2002

Parasitology Research

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When given orally, quinine or salinomycin cause irreversible damage to the plasmodial developmental stages of Henneguya sp., a gill parasite in the tapir fish Gnathonemus petersii. Naturally infected tapir fish measured 75-169 mm in total length and their total weight ranged over 4.3-11.7 g. The fish bore 7-77 plasmodia in their gill arches. Medicinal food containing either quinine (5 g/1000 g food) or salinomycin (0.075 g/1000 g food) was given once a day to naturally infected fish in a food chain via water fleas ( Daphnia spp) for a period of 3, 6, or 9 days. From the monitored feeding of the tapir fish and weight determinations of the water fleas, it was calculated that gross uptake was 18.5 micro g/kg body weight fish daily for pure salinomycin and was 1.25 mg/kg body weight daily for quinine. After the end of the experiments, the fish were sacrificed and the plasmodia were carefully prepared from the gill arches and processed for transmission electron microscopy. As seen by ultrastructure investigations, for both substances the grade of damage in the parasites correlated positively with the period of application. When quinine was given for a 3-day period, the trophozoite ecto- and endoplasm exerted numerous vacuoles, caused by the drug, and the presporogonous and the pansporoblastic stages were malformed. Following a 6-day period, numerous abortive polar capsules were found in the trophozoite cytoplasm. To a large extent, the limiting membranes of the polaroblasts and valvogenic cells were destroyed. In addition, deep clefts between the polaroblasts, the valvogenic cells and between the two sporoblasts were observed. Following a 9-day treatment, all damage increased and, in addition, generative cells and two-cell stages were no longer detectable. As a first sign for the effects of salinomycin, following a 3-day treatment, a shrinking of the whole plasmodia occurred and the sutures in the pansporoblasts were enlarged. The polar capsules were malformed and the zonar structures of the polar filament were no longer detectable. The sporoplasmosomes were more electron-pale than those of the control samples. After a 9-day treatment, the pansporoblasts were completely destroyed. Under the experimental conditions chosen, both compounds were very well tolerated by the fishes.

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Quinine and Quinine Analogues

Hofheinz¹,

Merkli²

1984

Handbook of Experimental Pharmacology

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Quinine

Cited by 3 publications

References 24 publications

Sterol−Polyamine Conjugates as Synthetic Ionophores

Sterol−Polyamine Conjugates as Synthetic Ionophores

Effects of orally administered chemotherapeutics (quinine, salinomycin) against Henneguya sp. Thelohán, 1892 (Myxozoa: Myxobolidae), a gill parasite in the tapir fish Gnathonemus petersii Günther, 1862 (Teleostei)

Quinine and Quinine Analogues

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