ABSTRACT
A new bis-iridoid glucoside, korolkoside (1), was isolated from Lonicera korolkovii, and its structure and stereochemistry were determined by spectroscopic analysis and chemical derivatization. Korolkoside (1) consists of two secologanin moieties that are connected by an acetal linkage.
Subject(s)
Glucosides/isolation & purification , Iridoids , Plants, Medicinal/chemistry , Animals , Chromatography, High Pressure Liquid , Glucosides/chemistry , Glucosides/toxicity , Iridoid Glucosides , Magnetic Resonance Spectroscopy , Male , Mice , Mice, Inbred Strains , Molecular Conformation , Molecular Structure , Pyrans/chemistry , Spectrophotometry, Infrared , StereoisomerismABSTRACT
Aplyronine A is a macrolide isolated from Aplysia kurodai. By monitoring fluorescent intensity of pyrenyl-actin, it was found that aplyronine A inhibited both the velocity and the degree of actin polymerization. Aplyronine A also quickly depolymerized F-actin. The kinetics of depolymerization suggest that aplyronine A severs F-actin. The relationship between the concentration of total actin and F-actin at different concentrations of aplyronine A suggests that aplyronine A forms a 1:1 complex with G-actin. From these results, it is concluded that aplyronine A inhibits actin polymerization and depolymerizes F-actin by nibbling. Comparison of the chemical structure of aplyronine A and another actin-depolymerizing macrolide, mycalolide B, suggests that the side-chain but not the macrolide ring of aplyronine A may account for its actin binding and severing activity.
Subject(s)
Actins/metabolism , Lactones/pharmacology , Serine/analogs & derivatives , Actins/drug effects , Animals , Aplysia , Enzyme Inhibitors/pharmacology , Kinetics , Lactones/chemistry , Macrolides , Marine Toxins , Muscle, Skeletal/metabolism , Myosins/antagonists & inhibitors , Oxazoles/chemistry , Oxazoles/pharmacology , Phalloidine/pharmacology , Rabbits , Serine/chemistry , Serine/pharmacology , Tropomyosin/metabolismABSTRACT
The process of occurrence of bright blindness, progressive retinal degeneration (PRD), in sheep was observed using two Suffolk ram lambs fed on a diet containing bracken powder. The first sign of the bright blindness was detected 4 months after the start of experiment. Based on these preliminary results, the amount of bracken powder necessary to induce PRD was estimated (experiment I). In the following experiment, ptaquiloside (PT), a norsesquiterpene glucoside of the illudane type isolated from bracken, which is a bracken carcinogen and a causative principle of cattle bracken poisoning was administered to two Suffolk ram lambs. It was clearly demonstrated in this experiment (experiment II) that PT present in bracken is also a causative principle of PRD.
Subject(s)
Animal Feed , Indans , Plant Poisoning/veterinary , Retinal Degeneration/veterinary , Sesquiterpenes , Sheep Diseases , Terpenes/toxicity , Animals , Bone Marrow/pathology , Male , Photoreceptor Cells/pathology , Plant Poisoning/pathology , Retina/pathology , Retinal Degeneration/etiology , Retinal Degeneration/pathology , Sheep , Terpenes/administration & dosage , Terpenes/isolation & purificationABSTRACT
Acute bracken fern toxicity in a calf was reproduced with ptaquiloside, a norsesquiterpene glucoside, isolated from the boiling water extract of bracken fern. Ptaquiloside was dissolved in 500 ml of saline and administered by drench at increasing dosages for six days out of every seven for the following periods: 400 mg/day for 24 days, 800 mg/day for 14 days and 1600 mg/day for four days. Neutrophilic granulocytes began to decrease markedly around 50 days after the start of the experiment, and granulocytopenia continued for a further 35 days until the autopsy, despite the discontinuance of ptaquiloside administration. Thrombocytes showed a relatively slow depression and reached 1 X 10(5)/mm3 at the lowest level. The calf was autopsied 86 days after the start of administration of ptaquiloside. Sternal bone marrow was found to be mostly replaced with fat marrow and only small foci of erythropoietic cells and a small number of megakaryocytes remained.
Subject(s)
Cattle Diseases/etiology , Indans , Plant Extracts/poisoning , Plant Poisoning/veterinary , Sesquiterpenes , Terpenes/poisoning , Agranulocytosis/etiology , Agranulocytosis/veterinary , Animals , Cattle , Female , Hemorrhage/etiology , Hemorrhage/veterinary , Leukocyte Count/veterinary , Leukocytosis/etiology , Leukocytosis/veterinary , Plant Poisoning/etiology , Thrombocytopenia/etiology , Thrombocytopenia/veterinaryABSTRACT
The nature of the carcinogen present in bracken fern has not yet been elucidated. Very recently, we succeeded in isolating ptaquiloside, a novel norsesquiterpene glucoside of the illudane type, from bracken. Ptaquiloside was shown to be a carcinogenic principle of bracken fern. It induces mammary cancer and multiple ileal tumors in high incidences when given orally to female Sprague-Dawley rats.
Subject(s)
Carcinogens/isolation & purification , Ileal Neoplasms/chemically induced , Indans , Mammary Neoplasms, Experimental/pathology , Plants , Sesquiterpenes , Terpenes/isolation & purification , Animals , Female , Ileal Neoplasms/pathology , Rats , Rats, Inbred Strains , Terpenes/toxicityABSTRACT
Isolation of the carcinogen in the boiling water extract of bracken fern was conducted by following the active principle with a carcinogenicity bioassay. Fractionation of the bracken extract was carried out using adsorption on resin (Amberlite XAD-2 and TOYOPEARL HW-40 (c] and organic solvent extraction. A diet containing each of the fractions was given to 7 female Charles River Sprague-Dawley rats (CD rats) of 4 weeks old, except for the second fraction. All 7 rats given the last carcinogenic fraction developed mammary and intestinal tumors and 5 rats had urinary bladder tumors. Ptaquiloside (PT) which induced mammary cancer in female CD rats and rho-hydroxystyrene glycosides were isolated from this fraction.
