Transformações químicas do (+)-10b,14-diol-allo-aromadendrano, isolado de duguetia glabriuscula r. e. fries (r. e. fries) (annonaceae) e avaliações biológicas de alguns derivados obtidos

The sesquiterpene (+)-allo-aromadendrane-10b-14-diol 1 was the lead compound to the preparation of several derivatives in order to test their biological activity against A. salina, C. sphaerospermum, E. coli and S. aureus. In this way the monoalcohols (+)-viridiflorol 4, 9 and 11 were synthesized from 1 together with the acetal 6, the ketal 7, and the ketone 8. The oxirane 3 and nitrile 5 were also prepared using as an intermediate the tosylate derivative 2.

Estudo fitoquímico das cascas do caule de Duguetia glabriuscula - Annonaceae, biomonitorado pelo ensaio de toxicidade frente a Artemia salina leach

The extract obtained from stem bark of Duguetia glabriuscula - Annonaceae was evaluated by Brine Shrimp Lethality test (BSL). The bioactive compounds, oxobufoline and lanuginosine, two oxoaporphine alkaloids were isolated by activity-guided fractionation. In addition, the compounds asaraldehyde, (+)-allo-aromadendrane-10beta, 14-diol, and two aporphine alkaloids, polyalthine and oliveridine were also obtained.

Compostos magnéticos moleculares: o desenvolvimento de novos materiais magnéticos nanoestruturados

The development of new magnetic materials has attracted attention of researchers of different areas. In the last decades, a distinguished class of materials emerged in magnetism, in which the magnetic moment is delocalized over molecules. By varying the synthetic conditions it is possible to obtain a large variety of structures and properties using the same starting molecules. These materials have a great scientific appeal due to the possibility of presenting not only magnetic, but also optical or electrical transport properties. In this review we will present an overview of some molecular magnetic compounds, in particular molecular nanomagnets.

CTLA4 enhances the osteogenic differentiation of allogeneic human mesenchymal stem cells in a model of immune activation

Allogeneic mesenchymal stem cells (allo-MSCs) have recently garnered increasing interest for their broad clinical therapy applications. Despite this, many studies have shown that allo-MSCs are associated with a high rate of graft rejection unless immunosuppressive therapy is administered to control allo-immune responses. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) is a co-inhibitory molecule expressed on T cells that mediates the inhibition of T-cell function. Here, we investigated the osteogenic differentiation potency of allo-MSCs in an activated immune system that mimics the in vivo allo-MSC grafting microenvironment and explored the immunomodulatory role of the helper T cell receptorCTLA4 in this process. We found that MSC osteogenic differentiation was inhibited in the presence of the activated immune response and that overexpression of CTLA4 in allo-MSCs suppressed the immune response and promoted osteogenic differentiation. Our results support the application of CTLA4-overexpressing allo-MSCs in bone tissue engineering.