A new ruthenium polypyridine sensitizer for dye-sensitized solar cells (DSSCs) is proposed containing a hexasulfanyl–styryl-modified bipyridyl group as an ancillary ligand. The advantages of this dye are the much larger absorption coefficient and the small shift of the absorption envelope to the red. We compare this new dye, TG6 (cis-bis(thiocyanato)(2,2′-bipyridyl-4,4′-dicarboxylato){4,4′-bis[2-(4-hexylsulfanylphenyl)vinyl]-2,2′-bipyridine}ruthenium(II) mono(tetrabutylammonium) salt), to the current best-performing dye, N719 (cis-bis(thiocyanato)bis(2,2′-bipyridine-4,4′-dicarboxylato)ruthenium(II) bis(tetrabutylammonium) salt). We have applied a suite of evaluation tools including: varying the electrolyte, varying the TiO₂ film thickness, charge density and recombination rate constant measurements, fluorescence lifetime and magnitude, and transient absorption techniques. The combined results indicate that TG6, as presently constructed, can surpass the performance of N719 under some conditions, but is likely to need some modification before surpassing cells designed to give record energy efficiency using N719. The higher absorption coefficient may be relevant to mass-produced DSSCs on metal where thinner TiO₂ films are advantageous. The main disadvantage is the slight catalysis of the electron/electrolyte recombination, which is possibly due to the extended π-system. A factor that requires further optimization involves the complex interaction of the slightly lower LUMO position, the composition of the electrolyte, the band edge position of the TiO₂, and the electron injection rate. We show why the maximum output from TG6 cells will not occur using the exact electrolytes used to maximize N719 cells.

Remodeling of arterioles is a pivotal event in the manifestation of many inflammation-based cardio-vasculopathologies, such as hypertension. During these remodeling events, vascular smooth muscle cells (VSMCs) switch from a contractile to a synthetic phenotype. The latter is characterized by increased proliferation, migration, and invasion. Compounds with anti-inflammatory actions have been successful in attenuating this phenotypic switch. While the vast majority of studies investigating phenotypic modulation were undertaken in VSMCs isolated from large vessels, little is known about the effect of such compounds on phenotypic switch in VSMCs of microvessels (microVSMCs). We have recently characterized a novel homoisoflavonoid that we called 7-O-methylpunctatin (MP). In this study, we show that MP decreased FBS-induced cell proliferation, migration, invasion, and adhesion. MP also attenuated adhesion of THP-1 monocytes to microVSMCs, abolished FBS-induced expression of MMP-2, MMP-9, and NF-κB, as well as reduced activation of ERK1/2 and FAK. Furthermore, MP-treated VSMCs showed an increase in early (myocardin, SM-22α, SM-α) and mid-term (calponin and caldesmon) differentiation markers and a decrease in osteopontin, a protein highly expressed in synthetic VSMCs. MP also reduced transcription of cyclin D1, CDK4 but increased protein levels of p21 and p27. Taken together, these results corroborate an anti-inflammatory action of MP on human microVSMCs. Therefore, by inhibiting the synthetic phenotype of microVSMCs, MP may be a promising modulator for inflammation-induced arteriolar pathophysiology.

Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal plant indigenous to the Middle Eastern region and belongs to the Asteraceae family, which is known to be rich in sesquiterpene lactones. We subjected Achillea falcata extracts to bioassay-guided fractionation against the growth of HCT-116 colorectal cancer cells and identified four secotanapartholides, namely 3-β-methoxy- isosecotanapartholide (1), isosecotanapartholide (2), tanaphallin (3), and 8-hydroxy-3-methoxyisosecotanapartholide (4). Three highly oxygenated guaianolides were isolated for the first time from Achillea falcata, namely rupin A (5), chrysartemin B (6), and 1β, 2β-epoxy- 3β,4α,10α-trihydroxyguaian- 6α,12-olide (7). These sesquiterpene lactones showed no or minor cytotoxicity while exhibiting promising anticancer effects against HCT-116 cells. Further structure-activity relationship studies related the bioactivity of the tested compounds to their skeleton, their lipophilicity, and to the type of functional groups neighboring the main alkylating center of the molecule.