Design and Synthesis of a Compound Library Exploiting 5-Methoxyleoligin as Potential Cholesterol Efflux Promoter.

5-Methoxyleoligin and leoligin are natural occurring lignans derived from Edelweiss (Leontopodium nivale ssp. alpinum), displaying potent pro-angiogenic and pro-arteriogenic activity. Cholesterol efflux from macrophages is associated with reverse cholesterol transport which inhibits the development of cardiovascular disease. Within this study, we developed a modular and stereoselective total synthesis of 5-methoxyleoligin which can be readily used to prepare a novel compound library of related analogs. The target 5-methoxyleoligin was synthesized exploiting a recently disclosed modular route, which allows also rapid synthesis of analogous compounds. All obtained products were tested towards macrophage cholesterol efflux enhancement and the performance was compared to the parent compound leoligin. It was found that variation on the aryl moiety in 2-position of the furan ring allows optimization of the activity profile, whereas the ester-functionality does not tolerate significant alterations.

Leoligin, the Major Lignan from Edelweiss (Leontopodium nivale subsp. alpinum), Promotes Cholesterol Efflux from THP-1 Macrophages.

Leoligin is a natural lignan found in Edelweiss (Leontopodium nivale ssp. alpinum). The aim of this study was to examine its influence on cholesterol efflux and to address the underlying mechanism of action. Leoligin increases apo A1- as well as 1% human plasma-mediated cholesterol efflux in THP-1 macrophages without affecting cell viability as determined by resazurin conversion. Western blot analysis revealed that the protein levels of the cholesterol efflux transporters ABCA1 and ABCG1 were upregulated, whereas the SR-B1 protein level remained unchanged upon treatment with leoligin (10 µM, 24 h). Quantitative reverse transcription PCR further uncovered that leoligin also increased ABCA1 and ABCG1 mRNA levels without affecting the half-life of the two mRNAs in the presence of actinomycin D, a transcription inhibitor. Proteome analysis revealed the modulation of protein expression fingerprint in the presence of leoligin. Taken together, these results suggest that leoligin induces cholesterol efflux in THP-1-derived macrophages by upregulating ABCA1 and ABCG1 expression. This novel activity suggests leoligin as a promising candidate for further studies addressing a possible preventive or therapeutic application in the context of atherosclerosis.

Small molecule cardiogenol C upregulates cardiac markers and induces cardiac functional properties in lineage-committed progenitor cells.

BACKGROUND/AIMS: Cell transplantation into the heart is a new therapy after myocardial infarction. Its success, however, is impeded by poor donor cell survival and by limited transdifferentiation of the transplanted cells into functional cardiomyocytes. A promising strategy to overcome these problems is the induction of cardiomyogenic properties in donor cells by small molecules. METHODS: Here we studied cardiomyogenic effects of the small molecule compound cardiogenol C (CgC), and structural derivatives thereof, on lineage-committed progenitor cells by various molecular biological, biochemical, and functional assays. RESULTS: Treatment with CgC up-regulated cardiac marker expression in skeletal myoblasts. Importantly, the compound also induced cardiac functional properties: first, cardiac-like sodium currents in skeletal myoblasts, and secondly, spontaneous contractions in cardiovascular progenitor cell-derived cardiac bodies. CONCLUSION: CgC induces cardiomyogenic function in lineage-committed progenitor cells, and can thus be considered a promising tool to improve cardiac repair by cell therapy.

VUT-MK142 : a new cardiomyogenic small molecule promoting the differentiation of pre-cardiac mesoderm into cardiomyocytes.

Intra-cardiac cell transplantation is a new therapy after myocardial infarction. Its success, however, is impeded by the limited capacity of donor cells to differentiate into functional cardiomyocytes in the heart. A strategy to overcome this problem is the induction of cardiomyogenic function in cells prior to transplantation. Among other approaches, recently, synthetic small molecules were identified, which promote differentiation of stem cells of various origins into cardiac-like cells or cardiomyocytes. The aim of this study was to develop and characterise new promising cardiomyogenic synthetic low-molecular weight compounds. Therefore, the structure of the known cardiomyogenic molecule cardiogenol C was selectively modified, and the effects of the resulting compounds were tested on various cell types. From this study, VUT-MK142 was identified as the most promising candidate with respect to cardiomyogenic activity. Treatment using this novel agent induced the strongest up-regulation of expression of the cardiac marker ANF in both P19 embryonic carcinoma cells and C2C12 skeletal myoblasts. The activity of VUT-MK142 on this marker superseded CgC; moreover, the novel compound significantly up-regulated the expression of other cardiac markers, and promoted the development of beating cardiomyocytes from cardiovascular progenitor cells. We conclude that VUT-MK142 is a potent new cardiomyogenic synthetic agent promoting the differentiation of pre-cardiac mesoderm into cardiomyocytes, which may be useful to differentiate stem cells into cardiomyocytes for cardiac repair. Additionally, an efficient synthesis of VUT-MK142 is reported taking advantage of continuous flow techniques superior to classical batch reactions both in yield and reaction time.

Synthesis of novel pyrazolo[3,4-d]pyrimidine derivatives as potential anti-breast cancer agents.

A series of new 1-aryl-4-benzylidenehydrazinyl-3-methylsulphanyl-pyrazolo[3,4-d]pyrimidines 6a-p was synthesized. The cytotoxic activity of the newly synthesized compounds against human breast cancer cell line, MCF7 was investigated. Most of the test compounds showed potent antitumor activity comparable to that of doxorubicin. The 1-phenyl series (6a-i) exhibited better antitumor activity than 1-(4-methoxyphenyl) series (6j-p). 4-[2-(4-Fluorobenzylidene)hydrazinyl]-3-(methylsulphanyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (6d) was the most active compound in this study with IC(50) equal to 7.5 nM.

Construction of a xylanase A variant capable of polymerization.

The aim of our work is to furnish enzymes with polymerization ability by creating fusion constructs with the polymerizable protein, flagellin, the main component of bacterial flagellar filaments. The D3 domain of flagellin, exposed on the surface of flagellar filaments, is formed by the hypervariable central portion of the polypeptide chain. D3 is not essential for filament formation. The concept in this project is to replace the D3 domain with suitable monomeric enzymes without adversely affecting polymerization ability, and to assemble these chimeric flagellins into tubular nanostructures. To test the feasibility of this approach, xylanase A (XynA) from B. subtilis was chosen as a model enzyme for insertion into the central part of flagellin. With the help of genetic engineering, a fusion construct was created in which the D3 domain was replaced by XynA. The flagellin-XynA chimera exhibited catalytic activity as well as polymerization ability. These results demonstrate that polymerization ability can be introduced into various proteins, and building blocks for rationally designed assembly of filamentous nanostructures can be created.

Direct functionalization of (un)protected tetrahydroisoquinoline and isochroman under iron and copper catalysis: two metals, two mechanisms.

A highly facile, straightforward synthesis of 1-(3-indolyl)-tetrahydroisoquinolines was developed using either simple copper or iron catalysts. N-protected and unprotected tetrahydroisoquinolines (THIQ) could be used as starting materials. Extension of the substrate scope of the pronucleophile from indoles to pyrroles and electron-rich arenes was realized. Additionally, methoxyphenylation is not limited to THIQ but can be carried out on isochroman as well, again employing iron and copper catalysis.

Facile, solvent and ligand free iron catalyzed direct functionalization of N-protected tetrahydroisoquinolines and isochroman.

An efficient method for an iron catalyzed oxidative indolation and methoxyphenylation of N-protected tetrahydroisoquinolines and isochroman is described including subsequent facile deprotection.