Search

Chemical investigation on the endophytic fungus Penicillium sp. B21 from the leaf of Bruguiera sexangula var. rhynchopetala led to the isolation of a new compound, penicitrinone acetate (1), the structure of which was elucidated by spectroscopic methods, including 2D NMR techniques.

Ethylene receptors play important roles not only in regulation of growth and development but also in response to environmental stimuli of plants. However, there are few reports on ethylene receptors in soybean. In this article, putative ethylene receptors of soybean were searched from soybean genomic database ( http://www.phytozome.net/search.php ) and analyzed. The ethylene receptor gene family in soybean comprising eight members, designated as GmERS1-1, GmERS1-2, GmETR1-1, GmETR1-2, GmETR2-1, GmETR2-2, GmEIN4-1, and GmEIN4-2 corresponding with their homologous genes in Arabidopsis, were isolated and analyzed. Phylogenetic analysis indicated that the eight soybean ethylene receptors (SERs) were in two subfamilies and further divided into four groups, viz., groups I (GmERS1-1 and GmERS1-2), II (GmETR1-1 and GmETR1-2), VI (GmETR2-1 and GmETR2-2), and VII (GmEIN4-1 and GmEIN4-2). Protein structure of the members in groups I and II from subfamily I were more conserved than the members in other two groups from subfamily II. Expression patterns of the SERs were compared with the homologous genes in Arabidopsis. The results demonstrated that expression patterns of the SERs differed from Arabidopsis members in the same group, suggesting that SERs are involved in different signal pathways compared to ethylene receptors in Arabidopsis. Promoter analysis showed that the sequences of the members in each group were different from each other, and some specific binding elements of transcription factors detected in promoter sequences might explain the differences between the members in the same group. A novel soybean TPR protein (tetratricopeptide repeat protein), GmTPR, was identified to interact with GmETR1-1, apparently an important ethylene receptor in ethylene signaling pathway in soybean. This suggested that GmTPR might be a novel downstream component of the ethylene signaling pathway.

Three new dihydroisocoumarin penicimarins G–I (1–3), together with one known dihydroisocoumarin (4) and three known meroterpenoids (5–7), were obtained from a fungus Penicillium citrinum isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of spectroscopic data. The absolute configuration of 1 was determined by the X-ray diffraction analysis using Cu Kα radiation. The absolute configurations of 2 and 3 were determined by comparison of their circular dichroism (CD) spectra with the literature. All compounds were evaluated for their antibacterial activities and cytotoxic activities.

Silica-zirconia mixed oxide (SiO 2 -ZrO 2 ) was synthesized by sol-gel method; with SiO 2 -ZrO 2 as the support, CuCl 2 /SiO 2 -ZrO 2 catalyst was then prepared by ion-exchange and used in the liquid oxidative carbonylation of methanol to dimethyl carbonate (DMC). The results showed that the introduction of zirconium species into the amorphous silica leads to the formation of Si-O-Zr bonds and Bronsted acid sites. When the CuCl 2 /SiO 2 -ZrO 2 catalyst is calcined at 300–550°C in an inert atmosphere, CuCl 2 is dispersed and bounded on the surface of SiO 2 -ZrO 2 support; CuCl 2 can be auto-reduced to CuCl, which is then ion-exchanged with the surface Bronsted acid sites of the SiO 2 -ZrO 2 support to form Cu + species. As a result, most of copper remains to be highly dispersed on the surface of SiO 2 -ZrO 2 and only a small amount of chlorine is left over. The CuCl 2 /SiO 2 -ZrO 2 catalyst calcined at 450°C exhibits excellent activity in the oxidative carbonylation of methanol; under the conditions of 140°C, 2.4 MPa and a CO/O 2 ratio of 2, the conversion of methanol and the selectivity to DMC reach 10.0% and 79.4%, respectively.