Alcaloïdes de Zanthoxylum tsihanimposa

From the bark of Zanthoxylum tsihanimposa (Rutaceae) 5 furoquinoline and benzophenanthridine alkaloids were isolated. Three are known compounds: γ-fagarine, skimmianine and dihydrochelerythrinylacetone. The other two, dihydrochelerythrinylacetaldehyde and O-methyldihydrochelerythrinyl-acetone, are probably artefacts.     

Alcaloïdes chez les capparidaceae

Alkaloids were isolated from leaves of 33 of 36 species and l-stachydrine and l-3-hydroxystachydrine were the major components present. These alkaloids characterize the family Capparidaceae in the same way as do the glucosinolates.     

Alcaloïdes du Pandaca ochrascens

From leaves and root bark of Pandaca ochrascens ten alkaloids were isolated: apparicine, akuammicine, dehydro-19,20 condylocarpine, akuammidine, epi-16 dehydro-14,15 vincamine, ibogaine, iboluteine, ibogaline and also two new alkaloids, epi-19 ibogaine or (19R) 19-hydroxyibogaine and epi-19 iboxygaline or (19R) 19-hydroxyibogaline. The absolute configuration at C₁₉ of these new alkaloids and other alkaloids hydroxylated on 19 of the Iboga type is discussed.     

Alcaloïdes indoliniques du Strychnos variabilis

Three new indolinic alkaloids have been isolated from the root bark of Strychnos variabilis: strychnopivotine, unusual because the C₁₇ atom of the curane skeleton is lacking, 16-hydroxyisoretulinal and rosibiline, a derivative of N-desacetylretuline. Their structures were deduced from spectral data and that of rosibiline was confirmed chemically.     

Structure des caboxines: Alcaloïdes oxindoliques du Cabucala fasciculata

The structures of three new 11-monomethoxy pentacyclic oxindole alkaloids have been elucidated by chemical correlations with reserpinine: caboxine-A was assigned to the allo C₁₉-méthyl α series: 3S, 4R, 7S, 19S; isocaboxine-A and B to the epi-allo C₁₉-methyl α series and have, respectively, the following configurations 3R, 4S, 7S, 19S and 3R, 4S, 7R, 19S.     

Alcaloïdes de Zanthoxylum decaryi: la decarine,nouvel alcaloide dérivé de la benzophénanthridine

Four alkaloids have been isolated from the stem bark of Zatithoxylum decaryi. Three are known, dictamnine skimmianine, 4-methoxy-1- methyl-2-quinolone. The fourth decarine is new; its structure has been established as 9-methoxy-10-hydroxy-2,3-methylenedioxybenzophenanthridine.¹     

Indications de la recherche des anticorps anti-spermatozoïdes

The clinical significance of antisperm antibodies (ASA) is highly controversial. A significant percentage of infertile men and women present immunity to spermatozoa, suggesting that ASA may interfere with the fertilizing capacity. ASA can act negatively on sperm parameters, sperm-cervical mucus interaction, gamete fusion and possibly also on the first step of embryonic development. ASA are present in approximately 2.8% to 26% of the male population and 0.2% to 1.6% of women. The pathogenesis of immunity to spermatozoa had not been fully elucidated: breakdown of normal protective mechanisms, i.e. blood-testis barrier, or epithelial barrier in women, and other mechanisms of immunological sperm tolerance, such as regulation of suppressor T lymphocytes. The indication for antisperm antibody testing is based on clinical and laboratory findings of infertile patients. In men, indictions for ASA testing include a history of genital disease, surgery for genital abnormalities, vasectomy, obstruction or injuries of the male genital tract, infection of accessory glands, long-standing infertility, alteration of semen parameters (agglutination, motility), mucus penetration, and reduced fertilizing capacity in IVF. In many cases, no etiological cause of autoimmunity is found and a genetic predisposition has been suggested. A majority of women do not develop antisperm antibodies, despite repeated contact with spermatozoa during their sexual life. Upper genital tract infection is the main cause of isoimmunization in females, although sexual practices, endometriosis, surgery for cervical neoplasia, recurrent spontaneous abortion and long-term infertility may also be involved. Sperm-cervical mucus impairment is the most obvious effect of immunization in women associated with IVF failure. Autoantibodies are frequently associated with antisperm antibodies. One of the consequences of the success of ICSI has been a decreased research effort to further the understanding of the origin and relevance of antisperm antibodies and specific antibody-antigen interactions. A better understanding of the natural history of immunological infertility would be useful for patient conseiling and to develop the most effective, efficient and safest management strategies. Such data could also be useful for the development of new tests and immunological methods of male contraception.     

Les flavonoïdes de Doronicum grandiflorum

After isolation and identification of the flavonoid compounds of D. grandiflorum Lam., a comparison of the flavonoid patterns of four species of Doronicum was undertaken. The differences observed are discussed from the evolutionary point of view.     

Perspectives de l’analyse de la mobilité des spermatozoïdes

Several studies have shown a good correlation between sperm motility and fertility though the microscopic evaluation of the percentage of motile sperm is highly subjective by nature. Therefore in the last decade, various objectives methods have been proposed to overcome this problem. Two types of methods were developed: The methods based on the analysis of images obtained by microphotography, microcinematography and microvideography and the global, undirect methods based on physical principles. Several systems based on video and image analysis (Computer Aided Sperm Analysis, CASA) have been developed and are used in numerous laboratories of reproductive biology. CASA technology offers the possibility to analyse some characteristics of sperm motion which are related to the fertilization potential and to develop new parameters related to some important aspects of sperm behavior such as hyperactivation. However, there is a large amount of interactions between the operator and the CASA machine. CASA instruments are not “ready-to-use” robots: the reliability of CASA depends largely on the expertise and training of the user and the application of standardized procedures and quality control schemes. By contrast, there is only minimal interaction between the operator and the Sperm Quality Anlyser which is a new device measuring and index of sperm motility highly correlated to the concentration of progressively motile sperm. The device uses light passed through a small sample of semen introduced in a capillary tube to detect variations in optical density that result from moving particles. The reproducibility of the measurements is excellent, the device is easy to use and this is a potentially useful tool for field-work studies. Further investigations of this device in the managment of male infertility is warranted. Finally, both types of objectives approaches are complementary to the conventional analysis of sperm motility and they will not replace it. Standardized procedures have been proposed by the World Health Organization for the subjective evaluation of sperm motility. Such procedures are very useful to reduce significantly the intra- and interlaboratory variations but internal and external quality controls schemes indicate that they are not sufficient to achieve acceptable levels of variation and regular quality controls followed by the definition and the application of corrective procedures are required.     

Hyperparasitisme facultatif de parasitoïdes en cours de développement par les femelles des ectoparasitoïdes Eupelmus vuilleti et Eupelmus orientalis Craw

In a community of three ectoparasitoids, Dinarmus basalis, Eupelmus vuilleti and E. orientalis, the host Callosobruchus maculatus parasitised 48 h before by D. basalis, is accepted by E. vuilleti females after they have eliminated the eggs and neonatal larvae of D. basalis. This ovicidal and larvicidal behaviour enables E. vuilleti to develop on C. maculatus instead of D. basalis. E. vuilleti females are able to parasitise the L5 larval stage and the pupa of D. basalis: their larvae therefore feed at the expense of the developing parasitoid. This trophic level is that of hyperparasitism. However, E. vuilleti females rarely practise hyperparasitism on their own L5 larvae and on those of E. orientalis. This behaviour reveals a high behavioural plasticity enabled by intra- and interspecific recognition of parasitoids used as hosts. Hyperparasitism activity in E. orientalis females is higher than that in E. vuilleti females since they hyperparasitise host parasitoids more frequently without preferential species choice. However, E. vuilleti seems to be free from competitive pressure with E. orientalis, as the former penetrates deeply into a grain store contaminated with C. maculatus in contrast to E. orientalis females, which remain on the surface from where they escaped.