Visible-Light-Mediated TiO2-Catalyzed Aerobic Dehydrogenation of N-Heterocycles in Batch and Flow.

We report a simple and environmentally friendly method for synthesizing N-containing heterocycles via a visible-light-mediated aerobic dehydrogenation reaction. Using a nontoxic, stable, and inexpensive titanium dioxide catalyst, a variety of substituted quinoline, indole, quinoxaline, and 3,4-dihydroisoquinoline derivatives could be synthesized using the green oxidant molecular oxygen. Improved reactivity and scalability of this reaction were demonstrated by adapting the photochemical multiphasic reaction to a continuous flow system. To gain insight into the mechanism, we also conducted several mechanistic studies, including absorption analysis, light on-off testing, and NMR analysis. Especially, oxygen is reduced to hydrogen peroxide, and dimethyl sulfoxide is a critical scavenger of the oxidant byproduct for ensuring high yields.

Phellinstatin, a new inhibitor of enoyl-ACP reductase produced by the medicinal fungus Phellinus linteus.

A new trimeric hispidin derivative, phellinstatin, was isolated from a culture broth of the medicinal fungus Phellinus linteus and its structure was established by various spectral analysis. Phellinstatin strongly inhibited Staphylococcus aureus enoyl-ACP reductase with an IC(50) of 6 µM and also showed antibacterial activity against S. aureus and MRSA.

Electrical Transport and Thermoelectric Properties of SnSe-SnTe Solid Solution.

SnSe is considered as a promising thermoelectric (TE) material since the discovery of the record figure of merit (ZT) of 2.6 at 926 K in single crystal SnSe. It is, however, difficult to use single crystal SnSe for practical applications due to the poor mechanical properties and the difficulty and cost of fabricating a single crystal. It is highly desirable to improve the properties of polycrystalline SnSe whose TE properties are still not near to that of single crystal SnSe. In this study, in order to control the TE properties of polycrystalline SnSe, polycrystalline SnSe-SnTe solid solutions were fabricated, and the effect of the solid solution on the electrical transport and TE properties was investigated. The SnSe1-xTex samples were fabricated using mechanical alloying and spark plasma sintering. X-ray diffraction (XRD) analyses revealed that the solubility limit of Te in SnSe1-xTex is somewhere between x = 0.3 and 0.5. With increasing Te content, the electrical conductivity was increased due to the increase of carrier concentration, while the lattice thermal conductivity was suppressed by the increased amount of phonon scattering. The change of carrier concentration and electrical conductivity is explained using the measured band gap energy and the calculated band structure. The change of thermal conductivity is explained using the change of lattice thermal conductivity from the increased amount of phonon scattering at the point defect sites. A ZT of ~0.78 was obtained at 823 K from SnSe0.7Te0.3, which is an ~11% improvement compared to that of SnSe.

Thermoelectric Properties of Cu2SnSe3-SnS Composite.

Heavily doped degenerate semiconductors such as Cu2SnSe3 (CTSe) attracted attention in thermoelectric (TE) and optoelectronic fields, due to their high electrical conductivity and small band gap. The small Seebeck coefficient of undoped CTSe, however, is the major issue in achieving high TE performance (figure of merit, ZT). Here, we report that the Seebeck coefficient of CTSe can be controlled by adding SnS within a CTSe matrix. CTSe-SnS composite has not only high Seebeck coefficient in the range of 300-500 µVolt/K but thermal conductivity which is lower than that of pristine CTSe due to the scattering at the interface between the matrix and the SnS particles. A reasonable ZT of 0.18 is achieved at 570 K by adding a small amount (3 wt.%) of SnS to the CTSe matrix.

Isolation and antifungal activity of lignans from Myristica fragrans against various plant pathogenic fungi.

BACKGROUND: In a search for plant extracts with potent in vivo antifungal activity against various plant diseases, we found that treatment with a methanol extract of Myristica fragrans Houttyn (nutmeg) seeds reduced the development of various plant diseases. The objectives of the present study were to isolate and determine antifungal substances from My. fragrans and to evaluate their antifungal activities. RESULTS: Three antifungal lignans were isolated from the methanol extract of My. fragrans seeds and identified as erythro-austrobailignan-6 (EA6), meso-dihydroguaiaretic acid (MDA) and nectandrin-B (NB). In vitro antimicrobial activity of the three lignans varied according to compound and target species. Alternaria alternata, Colletotrichum coccodes, C. gloeosporioides, Magnaporthe grisea, Agrobacterium tumefaciens, Acidovorax konjaci and Burkholderia glumae were relatively sensitive to the three lignans. In vivo, all three compounds effectively suppressed the development of rice blast and wheat leaf rust. In addition, EA6 and NB were highly active against the development of barley powdery mildew and tomato late blight, respectively. Both MDA and NB also moderately inhibited the development of rice sheath blight. CONCLUSION: This is the first study to demonstrate the in vitro and in vivo antifungal activities of the three lignans from My. fragrans against plant pathogenic fungi.

Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi.

The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1).

Finding Meaning in Written Emotional Expression by Family Caregivers of Persons With Dementia.

This study tested the effect of written emotional expression on the ability to find meaning in caregiving and the effects of finding meaning on emotional state and psychological burden in 91 dementia family caregivers. In a pretest-posttest design, participants were randomly assigned to either an experimental or a comparison group. Experimental caregivers (n = 57) wrote about their deepest thoughts and feelings about caring for a family member with dementia, whereas those in the comparison group (n = 34) wrote about nonemotional topics. Results showed enhanced meaning-making abilities in experimental participants relative to comparison participants, particularly for those who used more positive emotion words. Improved meaning-making ability was in turn associated with psychological benefits at posttest, but experimental participants did not show significantly more benefit than comparison participants. We explore the mediating roles of the meaning-making process as well as some of the background characteristics of the individual caregivers and their caregiving environments.