Degradation of three ß-O-4 lignin model compounds via organic electrolysis and elucidation of the degradation mechanisms.

Woody biomass comprising cellulose, hemicellulose, and lignin has been the focus of considerable attention as an alternative energy source to fossil fuel for various applications. However, lignin has a complex structure, which is difficult to degrade. Typically, lignin degradation is studied using ß-O-4 lignin model compounds as lignin contains a large number of ß-O-4 bonds. In this study, we investigated the degradation of the following lignin model compounds via organic electrolysis: 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol 1a, 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol 2a, and 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol 3a. The electrolysis was conducted for 2.5 h at a constant current of 0.2 A using a carbon electrode. Various degradation products such as 1-phenylethane-1,2-diol, vanillin, and guaiacol were identified upon separation via silica-gel column chromatography. The degradation reaction mechanisms were elucidated using electrochemical results as well as density functional theory calculations. The results suggest that the organic electrolytic reaction can be used for the degradation reaction of a lignin model with ß-O-4 bonds.

Synthesis and biological evaluation of glucose conjugated phthalocyanine as a second-generation photosensitizer.

Photodynamic therapy (PDT) is a treatment method using light and photosensitizers (PSs), which is categorized as a non-invasive surgery treatment for cancers. When the tumor is exposed to a specific light, the PSs become active and generate reactive oxygen species (ROS), mainly singlet oxygen which kills nearby cancer cells. PDT is becoming more widely recognized as a valuable treatment option for localized cancers and pre-cancers of skin as it has no long-term effects on the patient. But, due to the limited penetration rate of light into the skin and other organs, PDT can't be used to treat large cancer cells or cancer cells that have grown deeply into the skin or other organs. Hence, in this study, our focus centers on synthesizing glucose-conjugated phthalocyanine (Pc) compatible with near-infrared (NIR) irradiation as second-generation photosensitizer, so that PDT can be used in a wider range to treat cancers without obstacles.

Design, synthesis, and biological evaluation of a highly water-soluble psoralen-based photosensitizer.

In recent years, photodynamic therapy (PDT) has been approved for treating various medical conditions, including cancer. PDT is a treatment that employs a particular drugs, called photosensitizers which work along with specific light source. The growth of this medical industry is expanding as it is another promising alternative to treat cancer which lessen the burden of treatments in patients. This includes the benefits of minimally invasive procedures and delivering high accuracy in targeting mutations. In recent two decades, cancer researchers have produced remarkable studies on developing photosensitizers that enhance understanding of biology and genetics of cancer. It is unfortunate that not all PDT can work as well as other profound treatment because PDT has various limitations like PDT leads photosensitivity reaction that arises when the photosensitizer remains in the body for a long period of time. In this paper, our studies centers on synthesizing a highly soluble photosensitizing agent with improved effectiveness on detecting cancer cells.

Synthesis of fluorescent molecular probes specific for the receptor of blepharismone, a mating-inducing pheromone of the ciliate Blepharisma japonicum.

Blepharismone (gamone 2) is a mating-inducing pheromone of the ciliate Blepharisma japonicum. N-Pyrenylbutyryl-blepharismone and N-biphenylacetyl-blepharismone, which are fluorescent derivatives of blepharismone, were synthesized as molecular probes for the gamone 2 receptor. Further, we proved that they have inhibitory activities against the blepharismone-induced monotypic pairing of B. japonicum.

Obstructive sleep apnea syndrome in children.

Obstructive sleep apnea syndrome (OSAS) in children is often caused by obstruction of the upper airway due to hypertrophy of the adenoids and palatine tonsils. Between October 1988 and December 1991, 50 children (34 males, 16 females) visited our department due to attacks of sleep apnea and underwent adenotomy or adeno-tonsillectomy. Respiratory monitoring during sleep was performed before and after operation, and the usefulness of the surgery was evaluated. Before operation, 27/ 50 children (54.0%) were diagnosed as having OSAS. Their age distribution showed peaks at the ages of 4 and 5 years and the male:female ratio was 2:1. Concerning the degree of improvement in clinical symptoms after surgery, marked effects were observed in 40/50 patients (80.0%), moderate effects in 7 (14.0%) and slight effects in 3 (6.0%). Concerning the degree of improvement in the apnea index after surgery in the 27 patients with OSAS, marked effects were observed in 22 patients (81.50%), moderate effects in 2 (7.4%), slight effects in 1 (3.7%) and no change in 2 (7.4%).