Exploring the Acid-Catalyzed Reactions of 10,11-Epoxy-Dibenzo[,]cycloheptan-5-ol as the Synthetic Modules toward Polycyclic Aromatic Scaffolds.

The structural diversity of polycyclic aromatic hydrocarbons (PAHs) offers exciting opportunities for their applications. Yet, selective synthesis of such conjugated networks poses a formidable challenge. Compared to the prominence of transition-metal-catalyzed cross-coupling and oxidative Scholl reactions, cationic rearrangement in the synthesis of polycyclic aromatic hydrocarbon is an underexplored subject.

Singlet Biradical Versus Triplet Biradical/Zwitterion Characteristics in Isomers of C -C -C -C -C -Fused Pentacyclic Aromatic Hydrocarbons Revealed through Reactivity Patterns.

Among various polycyclic aromatic hydrocarbons, C -C -C -C -C fused pentacyclic aromatic hydrocarbons have the unique potential to adopt quinonoid, zwitterion, singlet, or triplet biradical electronic configurations. Two such hybrid structures between pentacene and azulene were synthesized and their ground state electronic configurations were deduced from the reactivity patterns they exhibit respectively. Compound 6, where the radicaloid carbons are linked through a para-phenylene, forms a head-to-head dimer like a singlet biradical.

Tuning the LUMO Levels of Z-Shaped Perylene Diimide via Stepwise Cyanation.

The central dogma in constructing organic electron acceptors is to attach electron-withdrawing groups to polycyclic aromatic hydrocarbons. Yet, the full potentials of many organic acceptors were never realized due to synthetic obstacles. By combining the Wittig-Knoevenagel benzannulation, the Pd(0)-catalyzed cyanation, and nucleophilic addition/oxidation cyanation, six polynitrile Z-shaped perylene diimide were synthesized.

Synthesis and Physical Study of Perylene and Anthracene Polynitrile as Electron Acceptors.

Attaching electron-withdrawing nitrile groups to π-conjugated systems is an effective approach toward electron acceptors. By combining various cyanation methodologies, perylene and anthracene polynitriles with up to eight nitrile substituents on one aromatic scaffold were synthesized. This strategy produces stable electron acceptors with lowest unoccupied molecular orbital (LUMO) levels comparable to benchmark acceptors.

Dicyclopenta[ghi,pqr]perylene as a Structural Motif for Bowl-Shaped Hydrocarbons: Synthetic and Conformational Studies.

Dicyclopenta[ghi,pqr]perylene (DCPP) is a substructural fragment on the surface of C yet not on C. Unlike its intensely investigated buckybowl cousins, corannulene and sumanene, DCPP is largely ignored due to the lack of synthetic accessibility. This communication describes the first preparation of a DCPP derivative from bay substituted perylene bis(4-(trifluoromethyl)phenyl)methanol as the key cyclization precursor.

Face-to-Face Packing of 2,3,9,10-Tetrasubstituted Pentacene Derivatives Revealed through a Solid State [4 + 4] Thermal Cycloaddition and Molecular Dynamic Simulation.

2,3,9,10-Substituted pentacene tetraesters and pentacene diester-dinitriles were synthesized. These pentacene derivatives underwent an unusual solid state [4 + 4] thermal dimerization with good efficiency and complete stereoselectivity. This observation indicates this series of pentacene derivatives adopt π-π stacking geometry with large mutual overlap in solid state.

Electrokinetics of polar liquids in contact with nonpolar surfaces.

Zeta potentials of several polar protic (water, ethylene glycol, and formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three nonpolar surfaces using closed-cell electroosmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes, and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited substantial electrokinetics in contact with the nonpolar surfaces with these observations: the electrokinetic effect on the fluorocarbon-coated surface is the strongest and on a PDMS grafted surface, the effect is the weakest.

Synthesis and biological evaluation of helioxanthin analogues.

Helioxanthin and analogues have been demonstrated to suppress gene expression of human hepatitis B virus. In the continuous attempt to optimize antiviral activity, various structural motifs were grafted on the helioxanthin scaffold. Many such analogues were synthesized and evaluated for their anti-hepatitis B virus activity.

New synthetic routes to Z-shape functionalized perylenes.

Z-shape (1,2,7,8-tetrasubstituted) perylene derivatives are novel chromophores with great potential in various applications. Yet, the synthetic entry into this class of molecules is hitherto quite limited. In this communication, the synthesis of a series of Z-shape perylene derivatives via a double Wittig-Knoevenagel benzannulation protocol is reported.

Anti-Mullerian hormone serum level as a predictive marker of ovarian function in Taiwanese women.

Background: Anti-Mullerian hormone (AMH), which is secreted by preantral and small antral follicles, has been found to be a valuable marker of ovarian reserve. The purpose of this study was to determine age-related changes in AMH levels that occur in Taiwanese women and to determine whether measuring AMH is a highly sensitive and specific tool for diagnosing polycystic ovarian syndrome (PCOS) in Taiwanese women.

Methods: A group of 59 healthy, fertile, regularly cycling women, a second group of seven patients with premature ovarian failure or menopause, and a third group of 45 PCOS patients were enrolled.

Synthesis of electron deficient acene derivatives via a bidirectional iterative elongation reaction.

Previously, we developed an iterative elongation methodology to synthesize acene esters, nitriles, and imides. The strategy uses the concept of bidirectional synthesis, and we can now make a series of electron deficient anthracene, tetracene, and pentacene derivatives via the bidirectional iterative elongation protocol. Central units, used to initiate the bidirectional elongation, were synthesized by employing a double anionic Fries rearrangement as the key step.

Synthesis and the biological evaluation of arylnaphthalene lignans as anti-hepatitis B virus agents.

We have previously shown that helioxanthin can suppress human hepatitis B virus gene expression. A series of helioxanthin analogues were synthesized and evaluated for their anti-hepatitis B virus activity. Modifications at the lactone rings and methylenedioxy unit of helioxanthin can modulate the antiviral activity.

Synthesis of benzo[c] and naphtho[c]heterocycle diesters and dinitriles via homoelongation.

Syntheses of benzo[c] and naphtho[c]heterocycle diesters and dinitriles were achieved via our newly developed iterative elongation protocol. The photophysical and electrochemical properties of these conjugated systems are explored.

Iterative synthesis of acenes via homo-elongation.

Starting from aromatic ortho-dialdehydes, we devised a homo-elongation protocol that combines a Wittig olefination and subsequent intramolecular Knoevenagel condensation to produce acene diesters and dinitriles.

Using electrocapillarity to measure the zeta potential of a planar hydrophobic surface in contact with water and nonionic surfactant solutions.

A method is introduced for determining the zeta potential of planar surfaces by combining electroosmosis and capillarity. In this method, an electric field is applied across the channel, which is filled with aqueous solution seeded with fluorescent tracer particles. Some excess liquid is applied on both ends of the channel, which bulges out and modulates the capillary force across the channel by adjusting its curvature.

Helioxanthin inhibits interleukin-1 beta-induced MIP-1 beta production by reduction of c-jun expression and binding of the c-jun/CREB1 complex to the AP-1/CRE site of the MIP-1 beta promoter in Huh7 cells.

An elevated level of macrophage inflammatory protein-1beta (MIP-1beta) induced by IL-1beta has been correlated with chronic hepatic inflammatory disease. However, molecular mechanism of IL-1beta-induced MIP-1beta expression in hepatic cells is obscure. Previously, we reported the mechanism of the anti-hepatitis B virus (HBV) activity of helioxanthin (HE-145).

The role of helioxanthin in inhibiting human hepatitis B viral replication and gene expression by interfering with the host transcriptional machinery of viral promoters.

A non-nucleosidic compound, Helioxanthin (HE-145), was found to suppress HBV gene expression and replication in HCC cells. To understand the molecular mode of action of HE-145 on HBV gene expression, the effects of HE-145 on four viral promoter activities using luciferase as a reporter were examined. It was found that HE-145 selectively suppresses surface antigen promoter II (SPII) and core promoter (CP) but has no effect on surface antigen promoter I (SPI) or promoter for X gene (Xp).

Syntheses of ladder-type oligonaphthalene derivatives and their photophysical and electrochemical properties.

Ladder-type oligophenylene derivatives are important compounds for light-emitting devices. However, the closely related ladder-type oligonaphthalene derivatives have received little attention due to the lack of synthetic accessibility. We hereby report the syntheses of these novel conjugated systems by means of an intramolecular cationic cyclization protocol.

Synthesis of tetracene sulfoxide and tetracene sulfone via a cascade cyclization reaction.

A facile synthesis of tetracene sulfoxides and sulfones based on o-diallene annulation initiated cascade cyclization was developed. The photophysical behavior of these tetracene derivatives can be generally rationalized by the presence of electron-withdrawing sulfoxides and sulfones at the 5-position.

Synthesis of anthracene ethers from anthracene methyl ethers via an acid-catalyzed exchange reaction.

Selective synthesis of anthracene ethers was achieved under mild conditions via an acid-catalyzed ether-ether exchange reaction and its scope and limitations, as well as its potential in synthesizing anthracene-based crown ethers, tested.

Hydrogen-bond-assisted pi-stacking of shape-persistent cyclophanes.

The pi-stacking interaction between shape-persistent cyclophanes works cooperatively with multiple hydrogen bonding sites to form cyclophane dimers. These findings considerably broaden the applicability of pi-stacking interactions as a driving force in self-assembly chemistry. A gel formation effect was also noticed in one of the cyclophanes.