glaucarubin and quassin

A stable cation radical Weitz' aminium salt, tris(4-bromophenyl)aminium hexachloroantimonate (BAHA) initiated electron transfer has been found to efficiently promote a great variety of reactions on electron-rich substrates: e.g. the cation radical pericyclic reactions, the chain-induced cation radical oxygenation of strained olefines and dienes, and several other intriguing reactions on a great variety of electron-rich substrate. The discovery of the Weitz' aminium salt catalysed Diels-Alder reaction has stimulated interest in cation radical chemistry and facilitated the development of a wide range of cation radical pericyclic chemistry. Applications of the method to the synthesis of natural products utilizing BAHA are also presented. Reaction of a lignan precursor, cinnamyl alcohols with BAHA in tetrahydrofuran (THF) gave a furofuran lignan, (+/-)-sesamin in one step. Podophyllum lignans, (+/-)-isopodophyllotoxin and (+/-)-isopicropodophyllin were synthesized by a biomimetic procedure from the doubly unsaturated esters by means of the BAHA induced cation-radical cycloaddition reaction. A new general synthesis for (+/-)-dibenzocyclooctadiene lignans was established utilizing novel synthetic method for quinone derivatives by oxidation with BAHA. Reactions of phenol derivatives using BAHA gave the corresponding quinone derivatives, which may be useful synthon for obtaining quassinoids such as quassin.

Topics: Antimony; Chemistry, Organic; Glaucarubin; Lignans; Molecular Conformation; Organic Chemistry Phenomena; Organometallic Compounds; Quassins; Quinones

Topics: Amebicides; Animals; Anti-Inflammatory Agents; Antimalarials; Antineoplastic Agents, Phytogenic; Antiviral Agents; Chemical Phenomena; Chemistry; Glaucarubin; Humans; Insecticides; Leukemia; Phenanthrenes; Quassins

A total synthesis of (+)-quassin from naturally occurring (S)-(+)-carvone is described. The total number of steps was 28, and the overall yield was about 2.6%. The synthetic strategy for the construction of the tetracyclic carbon framework was based on a C-->ABC-->ABCD ring annulation sequence, involving an aldol reaction, an intramolecular Diels-Alder reaction, and an intramolecular acylation as the key steps. Subsequent functionalization of ring A and ring C then afforded the target (+)-quassin.

Topics: Antineoplastic Agents, Phytogenic; Glaucarubin; Indicators and Reagents; Magnetic Resonance Spectroscopy; Quassins; Stereoisomerism

The crude methanol extract of the stem wood of Quassia amara. L. (A-1) significantly caused a reduction in the weight of the testis, epididymis and seminal vesicle, but an increase in that of the anterior pituitary gland. Epididymal sperm counts, serum levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were significantly reduced when the rats were treated with the extract. Furthermore the basal and LH-stimulated testosterone secretion of Leydig cells isolated from rats pretreated with the extract was inhibited. These changes seemed to be restored eight weeks after the withdrawal from extract treatments. Two compounds - quassin and 2-methoxycanthin-6-one were isolated after fractionation of A-1. Quassin produced similar biological actions as the crude extract while the effects of 2-methoxycanthin-6-one did not seem to differ from those of the control. Quassin appears to be the antifertility principle of Quassia amara.

Topics: Animals; Antimalarials; Body Weight; Carbolines; Fertility; Follicle Stimulating Hormone; Glaucarubin; Luteinizing Hormone; Male; Oleanolic Acid; Organ Size; Plant Extracts; Plants, Medicinal; Quassins; Rats; Rats, Wistar; Sperm Count; Testis; Testosterone

Four new quassinoids named samaderines X (1), Y (2) and Z (3), and indaquassin X (5), and a new C19 quassinoid glycoside, 2-O-glucosylsamaderine C (10), together with five known quassinoids, samaderines B (7), C (8), and E (4), indaquassin C (6), and simarinolide (9), were isolated form the stems of Quassia indica (Simaroubaceae), an Indonesian medicinal plant. The chemical structures of these quassinoids have been elucidated on the bases of their chemical and physiochemical properties. Samaderines X (1), Z (3), E (4), and B (7) were shown to exhibit significant growth-inhibitory activity against the cultured malarial parasite Plasmodium falciparum (a chloroquine- resistant K1 strain), and 1--8 were shown to exhibit in vitro cytotoxicity (IC50: 0.04--100 micrograms/ml) against KB cells. Samaderines X (1), B (7) and C (8), as well s indaquassin X (5), exhibited inhibitory activity in the in vitro endothelial cell-neutrophil leukocyte adhesion assay, whereas samaderines X (1) and B (7) were found to exhibit significant anti-inflammatory activity.

Topics: Animals; Antimalarials; Antineoplastic Agents, Phytogenic; Drug Screening Assays, Antitumor; Glaucarubin; Humans; Hydrolysis; Indonesia; KB Cells; Magnetic Resonance Spectroscopy; Molecular Conformation; Plant Stems; Plants, Medicinal; Plasmodium falciparum; Quassins; Tumor Cells, Cultured

The crude methanol extract of the stem wood of Quassia amara L. inhibited both the basal and LH-stimulated testosterone secretion of rat Leydig cells in a dose-dependent fashion. Fractionation of the extract by chromatography gave quassin (1) and 2-methoxycanthin-6-one (2); compound 1 proved to be the bioactive agent.

Topics: Animals; Cells, Cultured; Fertility; Glaucarubin; Leydig Cells; Male; Plants, Medicinal; Quassins; Rats; Rats, Wistar; Testosterone

Quassin, a mosquito larvicide isolated from Quassia amara, inhibits tyrosinase activity in the larvae of Culex quinquefasciatus. Since tyrosinase is directly involved in sclerotisation of the cuticle, it is suggested that quassin, as a larvicide, inhibits development of the cuticle. In presence of quassin phenylalanine, tyrosine and L-dopa levels were increased in larvae. In the larval stages, mosquitoes have a high concentration of phenylalanine and tyrosine with the level of the latter being very high just before pupation and then declines sharply. Monoamine oxidase (MAO), an enzyme directly involved in the metabolism of catecholamines, remained unaffected by quassin, in fact the level of adrenaline also remained unchanged in larvae during quassin poisoning. MAO showed high variation in its activity between synthetic and natural substrates. Tyramine is not a substrate for MAO. Tyrosinase activity was high in developing stages and negligibly low in adults and showed specificity to L-dopa. Phenylalanine and tyramine are unaffected by tyrosinase. Blood feeding did not influence the activity of both these enzymes.

Topics: Animals; Catecholamines; Culex; Female; Glaucarubin; Insecticides; Male; Monoamine Oxidase; Monophenol Monooxygenase; Quassins

Crushed aqueous extracts of leaf, wood, bark and flowers of Quassia amara showed antilarval activity against C quinquefasciatus. Quassin has been identified to be the antilarval principle present in this plant and was effective against mosquito larvae at a concentration of 6 ppm. Quassin was present to the extent of 0.1 to 0.14 per cent (average 0.12%) on a dry weight basis in wood of Q. amara. This compound is an unsaturated lactone and it gave a positive response to the Legal test, characteristic of unsaturated lactones. Quassin lost its antilarval activity on treatment with strong alkalies. Quassin was over five times as active as carbaryl, a synthetic antilarval agent.

Topics: Animals; Culex; Glaucarubin; Insecticides; Larva; Molecular Structure; Mosquito Control; Plants; Quassins

A microdilution technique for the assessment of in vitro activity against Entamoeba histolytica was devised and validated with metronidazole. The test was used to detect the antiamoebic activities of plant extracts prepared from the traditional remedies Brucea javanica fruits and Simarouba amara stems. The activity was associated with quassinoid-containing fractions. The 50% inhibitory concentrations for some quassinoids against amoebae were determined by using the microdilution method. These concentrations ranged from 0.019 micrograms.ml-1 for bruceantin, the most active quassinoid, to greater than 5 micrograms.ml-1 for glaucarubol, the least active compound tested. These results are discussed with reference to the known activities of these compounds against Plasmodium falciparum. Overall, the activities of the quassinoids against both protozoa are similar. The microdilution technique will be useful in the search for novel antiamoebic drugs.

Topics: Amebicides; Animals; Entamoeba histolytica; Fruit; Glaucarubin; Indicator Dilution Techniques; Metronidazole; Microchemistry; Phenanthrenes; Plant Extracts; Plants, Medicinal; Plasmodium falciparum; Quassins

Topics: Antineoplastic Agents, Phytogenic; Glaucarubin; Magnetic Resonance Spectroscopy; Phenanthrenes; Quassins

Topics: Animals; Cockroaches; Glaucarubin; Insecticides; Phenanthrenes; Plants; Quassins

A microtitration plate enzyme-linked immunosorbent assay has been developed for quassin and closely related seco-triterpenes. The method is much more sensitive than conventional chromatographic techniques and enables the routine analysis of large numbers of samples with a detection limit of 5 ng quassin. Antibody production was elicited by injecting a conjugate of iso-quassinic acid linked to bovine serum albumin into rabbits. Important features of the technique are (a) the use of a double-antibody, noncompetitive enzyme-linked immunosorbent assay for a low-molecular-weight, nonantigenic compound using microtitration plates; and (b) that the initial incubation of samples with primary antiserum can be carried out in buffer containing up to 20% (v/v) methanol with minimal loss of sensitivity. The structural requirements for recognition of the hapten by the antiserum are considered based on the levels of cross-reaction found with a wide range of other quassinoids.

Topics: Chemical Phenomena; Chemistry; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Glaucarubin; Methanol; Phenanthrenes; Quassins

Topics: Animals; Antineoplastic Agents, Phytogenic; Binding Sites; Glaucarubin; Phenanthrenes; Protein Biosynthesis; Quassins; Rabbits; Reticulocytes; Ribosomal Proteins; Ribosomes; Structure-Activity Relationship

Owing to its high toxicity, ailanthone, one of the most potent in vivo amoebicidal drugs of natural origin, cannot be safely employed in clinical trials. With the aim of obtaining a compound with a better therapeutic index and of studying possible relationships between biological activity and chemical structure, many derivatives of ailanthone and of the chemically related, although biologically inactive, quassin have been prepared and tested.

Topics: Amebicides; Glaucarubin; Phenanthrenes; Quassins