Enzymatic Synthesis of Ascorbic Acid-Ketone Body Hybrids

Molecular hybrids obtained by connecting two or more bioactive molecules through a metabolizable linker are used as multi-target drugs for the therapy of multifactorial diseases. Ascorbic acid, as well as the ketone bodies acetoacetate and (R)-3-hydroxybutyrate, are bioactive molecules that have common fields of application in the treatment and prevention of neurodegenerative diseases and cardiac injuries as well. In spite of this, the preparation of ascorbic acid ketone body hybrids is uncovered by the literature. Herein, we report the lipase-catalyzed condensation of methyl acetoacetate with ascorbic acid, which affords the 6-O-acetoacetyl ascorbic acid in quantitative yield. The same approach, employing the methyl (R)-3-hydroxybutyrate in place of the methyl acetoacetate, allows the preparation of the 6-O-(R)-3-hydroxybutyryl ascorbic acid in 57% yield. A better result (90% overall yield) is achieved through the lipase-catalyzed coupling of ascorbic acid with methyl (R)-3-O-methoxymethyl-3-hydroxybutyrate followed by the cleavage of the MOM protecting group. The two novel products are fully characterized and additional information on the antioxidant activity of the new products is also given.

Growth and development of succulent mixtures for extensive green roofs in a Mediterranean climate

Green roof systems, aimed at reducing anthropic impact on the environment, are considered environmental mitigation technologies and adopted by many countries across the world to strengthen urban ecosystem services. This study evaluates two mixtures of succulent: one of Crassulaceae and the other of Aizoaceae, used in the creation of a continuous and homogenous plant groundcover in Mediterranean environments. To assess the species mixtures, the parameters plant height, growth index, cover percentage and flowering were observed. Hydrological observations were also carried out to evaluate the rainfall retained by the test system in any given month. All data were subjected to analysis of variance. Growth indicators in the study showed trends characteristic of xeric plants, which tend to slow down in dry, summer climate conditions to the point of halting plant vertical growth and ground cover development completely. The Aizocaeae mix, during the initial stage, showed prevalent horizontal growth, confirmed by greater a greater growth index (13,21) and cover percentage (45%) compared to Sedum (Growth index: 3,61; Cover: 36%). In contrast, the Sedum mix recorded greater vertical growth at the beginning (Sedum mixture: 7.53 cm; Aizoaceae mixture: 6,11 cm). During the final stages of observations, however, greater vertical growth in the Aizoaceae (7,88 cm) became apparent together with a recovery in horizontal growth in the Sedum (79%), albeit not sufficient to outperform the Aizoaceae mixture (87%). Flowering in the two mixtures occurred between late spring and late summer. The Sedum mixture guaranteed a longer flowering period (130 days) compared to the Aizoaceae (93 days), with a gradual start followed by steady flower emission. Regarding rainfall water retention, a comparison of the mixtures in late winter/early spring revealed that the Sedum performed best (44.9 L m²vs 37.4 L m²), whilst the Aizoaceae outperformed the Sedum in Autumn (63 L m²vs 55 L m²), in conjunction with favorable growth rates in both species mixtures. Both mixtures demonstrated satisfying results and are considered suited to a Mediterranean environment. Furthermore, based on the different growth rates of the species in the two test mixtures, this study suggests that new combinations of Sedum and Aizoaceae together might prove more resilient in Mediterranean environments.

[2-dimensional echocardiography in infarct of the right ventricle: correlation with clinical, hemodynamic and scintigraphic findings]

Right ventricular wall motion was studied in 18 patients hospitalized for acute myocardial infarction by means of cross-sectional echocardiography. Diagnosis of right ventricle myocardial infarction was made on the basis of clinical, electrocardiographic, hemodynamic criteria, respectively present in 66%, 80% and 66% of our patients. Echocardiographic criteria of right ventricle infarction were: 1) right ventricle dilatation; 2) segmental or global right ventricle wall motion abnormalities; 3) paradoxical motion of interventricular septum; 4) tricuspid insufficiency; 5) inferior cava vein dilatation with paradoxical respiratory pattern. Seven patients were studied by means of radionuclide techniques, that confirmed right ventricle infarction in 6 patients. We conclude that: 1) the most accurate echocardiographic views for right ventricle wall motion study are subcostal views and, in particular, the subcostal short-axis (OAS 60 degrees); 2) those patients (12/18) with a specific echocardiographic pattern for right ventricle infarction presented a specific clinical and hemodynamic picture; 3) those patients (6/18) with only segmental right ventricular wall motion abnormalities presented an aspecific clinical and hemodynamic picture. Moreover we showed that an improvement of right ventricular wall motion was observed in some cases within a few days of the infarction. Further observations are needed to assess the frequency and late prognosis of acute right ventricle infarction.