Stemarane diterpenes and diterpenoids

In this article the scientific activity carried out on stemarane diterpenes and diterpenoids, isolated over the world from various natural sources, was reviewed. The structure elucidation of stemarane diterpenes and diterpenoids was reported, in addition to their biogenesis and biosynthesis. Stemarane diterpenes and diterpenoids biotransformations and biological activity was also taken into account. Finally the work leading to the synthesis and enantiosynthesis of stemarane diterpenes and diterpenoids was described

Intermolecular interaction and solid state characterization of abietic acid/chitosan solid dispersions possessing antimicrobial and antioxidant properties

The aim of this work was to prepare and characterize solid dispersions of abietic acid (AB) and chitosan (CS) to investigate how formulation of the mixture may help in the battle against microbial colonization in different areas, such as the biomedical field or the food industry. Solid dispersions were characterized by differential scanning calorimetry, infrared spectroscopy, Raman spectroscopy, polarized optical microscopy, zeta potential and size analysis. The data showed that the dispersion/solvent evaporation method formed solid dispersions in which abietic acid was molecularly dispersed in the carrier. A synergistic effect between the two components in terms of antioxidant and antimicrobial properties was found, especially in the formulations obtained with 1/1 AB/CS molar ratio. Interestingly, the aggregation state (amorphous/crystalline) of AB seemed to affect the antimicrobial activity of the formulation, suggesting increased bioactivity when the drug was in the amorphous state. These findings, together with the demonstrated biocompatibility of the formulations, seem to open promising perspectives for a successful application of the developed AB/CS formulations in the biomedical field or in the food industry

Novel locally active estrogens accelerate cutaneous wound healing-part 2

Estrogen deprivation is associated with delayed healing, while estrogen replacement therapy (ERT) accelerates acute wound healing and protects against development of chronic wounds. However, current estrogenic molecules have undesired systemic effects, thus the aim of our studies is to generate new molecules for topic administration that are devoid of systemic effects. Following a preliminary study, the new 17β-estradiol derivatives 1 were synthesized. The estrogenic activity of these novel compounds was evaluated in vitro using the cell line ERE-Luc B17 stably transfected with an ERE-Luc reporter. Among the 17β-estradiol derivatives synthesized, compounds 1e and 1f showed the highest transactivation potency and were therefore selected for the study of their systemic estrogenic activity. The study of these compounds in the ERE-Luc mouse model demonstrated that both compounds lack systemic effects when administered in the wound area. Furthermore, wound-healing experiments showed that 1e displays a significant regenerative and anti-inflammatory activity. It is therefore confirmed that this class of compounds are suitable for topical administration and have a clear beneficial effect on wound healing

Thymol-functionalized hyaluronic acid as promising preservative biomaterial for the Inhibition of Candida albicans biofilm formation

Hyaluronic acid (HA) is a naturally occurring biopolymer that has been employed for a plethora of medicinal applications. Nevertheless, as HA is a natural polysaccharide, it can be a substrate able to promote microbial growth and proliferation. Biopolymer–drug conjugates have gained attention over the years to overcome drawbacks of each single component. Within this context, thymol (Thy), a phenolic compound occurring in essential oils (EOs) extracted from Thymus and Origanum, has been largely studied for its antimycotic applications. However, it is characterized by a low water solubility and moderate cytotoxicity. Herein, we report an innovative HA–thymol conjugate (HA-Thy) biomaterial to circumvent the drawbacks of free thymol use by providing the polymer conjugate with the beneficial properties of both components. Preliminary biological tests evidenced the decrease of thymol cytotoxicity for the HA-Thy conjugate, paired with a promising antibiofilm formation activity against Candida albicans, similar to pure thymol, highlighting its potential application as a preservative biomaterial in formulations

Le tavole murali di von Schroeder

(schede a cura di L.M. Migneco

Sulfur ylides in reactions with 4-substituted cyclohexanones: Stereochemistry and reactivity

The stereochemistry of the epoxidation reactions of the title compounds (R= Me, Et, t-Bu, Ph, p-F-Ph, OMe, OH, CF3, OCOPh) with sulfur ylides (dimethylsulfonium methylide and dimethyloxosulfonium methylide) has been determined in three different solvents (DMSO, C6H6 and THF). Relative rates have been measured and the kinetic constants k(cis) and k(trans) determined