NMR study of alkaloids. V.13C NMR spectra and reconsideration of the structures of 11- and 10-hydroxypleiocarpamines and the structures of new alkaloids fromVinca erecta
The structures of phenolic alkaloids isolated previously fromVinca erecta Rgl. et Schmalh. have been reconsidered on the basis of the results of a study of their13C NMR spectra, and it has been shown that a base with mp 228–229° has the structure of 11-hydroxystrictamine and an amorphous base of the same composition isomeric with it is 10-hydroxystrictamine. The structures of two new indolenine alkaloids — ercinamine and ercinaminine — have been determined from an analysis of13C NMR spectra, and also on the basis of PMR and IR spectra and chemical transformations.
Vegetation of Central Asia and Environs
Currently there is a gap of spatially and temporally explicit information on vegetation cover dynamics and trends in the post-Soviet Central Asia at spatial scales sufficient to support decision-making in the region. Insufficient information also exists concerning vegetation variability across climatic gradients as well as vegetation response across different land uses, from natural rangelands to intensively irrigated croplands. We analyzed vegetation cover changes in five Central Asian countries in this study. This analysis included trends in key vegetation phenological parameters derived from 250  m Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) timeseries data for 2000–2011. In order to follow the vegetation changes over time, we calculated trends in phenometrics using a robust trend analysis method. The results showed that inter-annual vegetation dynamics followed precipitation patterns only outside irrigated areas, while clearly differentiated winter and summer seasons were observed throughout the study area. Specifically spatial patterns of long-term vegetation trends allowed defining areas characterized by decrease in overall vegetation greenness and peak greenness as well as revealing the shifts in timing of occurrence of peak greenness over the monitoring period. The information obtained will prove as a useful guide in the selection of field sites for detailed vegetation surveys and land rehabilitation interventions as well as improvement of overall understanding of vegetation dynamics and variability in the remote regions of Central Asia.
The role of prolactin in andrology: what is new?
Prolactin (PRL) has been long deemed as a hormone involved only in female reproduction. However, PRL is a surprising hormone and, since its identification in the 1970s, its attributed functions have greatly increased. However, its specific role in male health is still widely unknown. Recently, low PRL has been associated with reduced ejaculate and seminal vesicle volume in infertile subjects. In addition, in men consulting for sexual dysfunction, hypoprolactinemia has been associated with erectile dysfunction and premature ejaculation, findings further confirmed in the general European population and infertile men. Several metabolic derangements, recapitulating metabolic syndrome, have also been associated with low PRL both in men with sexual dysfunction and from the general European population. In men with sexual dysfunction, followed-up for more than 4 years, low PRL was identified as an independent predictor of the incidence of major adverse cardiovascular events. Finally, an association with anxiety or depressive symptoms has been found in men with sexual dysfunction and from the general European population. While a direct role for impaired PRL function in the pathogenesis of these reproductive, sexual, metabolic and psychological disorders is conceivable, the possibility that low PRL is a mirror of an increased dopaminergic or a decreased serotonergic tone cannot be ruled-out. Hyperactivity of the dopaminergic system can explain only a few of the aforementioned findings, whereas a hypo-serotonergic tone fits well with the clinical features associated with low PRL, and there is significant evidence supporting the hypothesis that PRL could be a mirror of serotonin in the brain.