Fusicoccanes: diterpenes with surprising biological functions.

Fusicoccin is the best-studied member of a class of diterpenes sharing a 5-8-5 ring structure, called fusicoccanes. Fusicoccin was and still is a 'tool in plant physiology', targeting the main engine of plasma membrane transport, the P-type H(+)-ATPase, assisted by members of the 14-3-3 family. The key position of 14-3-3 proteins in cell biology, combined with a broader specificity of other fusicoccanes as shown by crystallography studies, make fusicoccanes a versatile tool in plant and animal biology. In this review, we examine recent evidence that fusicoccanes act on animal cells, describe the discovery of the fungal biosynthetic pathway and emphasize that lower (liverworts) and higher plants produce fusicoccanes with intriguing biological activities.

[The French pharmaceutical school of heterosides (glycosides)]. / L'école pharmaceutique française des hétérosides.

Under the influence of Emile Bourquelot, several French pharmacists at the Ecole supérieure de pharmacie de Paris and the Muséum national d'Histoire naturelle formed, at the end of the 19th century and during the first half of the 20th century, a veritable "French school of heterosides". Their work, which involved perfecting a new method for stabilizing the plants with ethanol and a process for enzymatic detection, led them to isolate and identify a large number of heterosides from a wide variety of plants. Bourquelot and Bridel also showed that the enzymatic reactions were reversible, a discovery that permitted the biochemical synthesis of these heterosides.

Glycosyl iodides. History and recent advances.

The use of glycosyl iodides as an effective method for the preparation of glycosides has had a recent resurgence in carbohydrate chemistry, despite its early roots in which these species were believed to be of limited use. Renewed interest in these species as glycosylating agents has been spurred by their demonstrated utility in the stereoselective preparation of O-glycosides, and other glycosylic compounds. This review provides a brief historical account followed by an examination of the use of glycosyl iodides in the synthesis of oligosaccharides and other glycomimetics, including C-glycosylic compounds, glycosyl azides and N-glycosides.

[Cardiac glycosides: From ancient history through Withering's foxglove to endogeneous cardiac glycosides]. / Hjerteglykosider: Fra oldtiden over Witherings digitalis til endogen glykosider.

For centuries, drugs that increase the power of contraction of the failing heart have been used for the treatment of congestive heart failure (dropsy). The cardiac effect is due to the content of cardiac glycosides. Squill or sea onion, Urginea (Scilla) maritima, a seashore plant, was known by the ancient Romans and Syrians and possibly also by the ancient Egyptians. Squills were used erratically, but some prescriptions indicate that they may have been used for the treatment of oedematous states. The toxic effect of strophanthus species was known from poisoned arrows used by the natives in Africa. Digitalis, derived form the foxglove plant, Digitalis purpurea, is mentioned in writings as early as 1250; a Welsh family, known as the Physicians of Myddvai, collected different herbs and digitalis was included in their prescriptions. However, the druge was used erratically until the 18th century, when William Withering, an English physician and botanist, published a monograph describing the clinical effects of an extract of the foxglove plant. Later, in 1785, the indication and the toxicity of digitalis were reported in his book, "An account of the Foxglove and some of its medical uses with practical remarks on dropsy, and other diseases". In Denmark, the leaves of Digitalis purpurea or Digitalis lanata were tested for cardiac glycoside activity. The standardized digitalis powder was used in tinctures, infusions, and tablets. The preparations were included in successive editions of the Danish pharmacopoeia, some of the tinctures already in 1828, i.e. before the standardization of the drug. Isolation of cardiac glycosides from digitalis, strophanthus and squill and determination of their chemical structures initiated biochemical and pharmacological studies. The scientific advances led to an understanding of cardiac muscle contractility and the Na,K pump as the cellular receptor for the inotropic action of digitalis. Examination of putative endogenous ligands to the receptor revealed some endogenous cardiac glycosides of similar or identical structures as those found in digitalis, strophanthus and squill. Increased concentrations of these glycosides are found in patients with heart failure. Further investigations are needed to determine whether the secretion of glycosides might be a physiologic response to a diminished cardiac output.

Compuestos cianogénicos en plantas empleadas en etnomedicina en El Chaco argentino / Composed cyanogen in plants employee in etnomedicine in the Argentine Chaco

En base a una encuesta nuestra anterior que abarcó a más de mil quinientas personas, respecto al empleo de plantas de la flora autóctona del chaco argentino en la medicina popular, hemos examinado la presencia de compuestos cianogénicos en las especies más utilizadas, con el objeto de validar su acción farmacológica o alertar sobre sus efectos tóxicos. Las especies analizadas son empleadas bajo diversas formas, tales como macerados, masticadas directamente, con el mate, como agua de beber, en infusiones o decocciones. En trabajos anteriores hemos informado sobre la presencia de saponinas y sapogeninas, antraquinonas y alcaloides en las mismas especies