Physicochemical characteristics and functional properties of high methoxyl pectin with different degree of esterification.

Moderate alkali de-esterification can change the physicochemical characteristics and thus the functional properties of high methoxyl pectin (HMP). The results revealed that de-esterification could increase negative charges (Zeta potential from -21 to -31 mV), decrease molecular weight (from 448 to 136 kDa) and apparent viscosity of HMP. Homogalacturonan (HG) content decreased (from 62% to 49%) while rhamnogalacturonan Ⅰ (RG-Ⅰ) content increased (from 32% to 46%) after de-esterification.

Structural characterization of pectin-bismuth complexes and their aggregation in acidic conditions.

Bismuth-contained therapies are effective in treating gastric ulcer and eliminating Helicobacter pylori (Hp). Anion polysaccharides ligand could reduce the intake of bismuth, and enhance drug efficacy of bismuth compounds. In this study, pectin-bismuth (PB) was prepared and the changes of PB structure in acidic environment were reported for the first time.

Five New Cytotoxic Metabolites from the Marine Fungus Neosartorya pseudofischeri.

The marine fungus Neosartorya pseudofischeri was isolated from Acanthaster planci from the South China Sea. In a preliminary bioactivity screening, the crude methanol extract of the fungal mycelia showed significant inhibitory activity against the Sf9 cell line from the fall armyworm Spodoptera frugiperda. Five novel compounds, including 5-olefin phenylpyropene A (1), 13-dehydroxylpyripyropene A (4), deacetylsesquiterpene (7), 5-formyl-6-hydroxy-8-isopropyl-2- naphthoic acid (9) and 6,8-dihydroxy-3-((1E,3E)-penta-1,3-dien-1-yl)isochroman-1-one (10), together with eleven known compounds, phenylpyropene A (2) and C (3), pyripyropene A (5), 7-deacetylpyripyropene A (6), (1S,2R,4aR,5R,8R,8aR)-1,8a-dihydroxy-2-acetoxy-3,8-dimethyl-5- (prop-1-en-2-yl)-1,2,4a, 5,6,7,8,8a-octahydronaphthalene (8), isochaetominine C (11), trichodermamide A (12), indolyl-3-acetic acid methyl ester (13), 1-acetyl-β-carboline (14), 1,2,3,4-tetrahydro-6-hydroxyl-2-methyl-l,3,4-trioxopyrazino[l,2-a]-indole (15) and fumiquinazoline F (16), were obtained.

Exploring the chemodiversity and biological activities of the secondary metabolites from the marine fungus Neosartorya pseudofischeri.

The production of fungal metabolites can be remarkably influenced by various cultivation parameters. To explore the biosynthetic potentials of the marine fungus, Neosartorya pseudofischeri, which was isolated from the inner tissue of starfish Acanthaster planci, glycerol-peptone-yeast extract (GlyPY) and glucose-peptone-yeast extract (GluPY) media were used to culture this fungus. When cultured in GlyPY medium, this fungus produced two novel diketopiperazines, neosartins A and B (1 and 2), together with six biogenetically-related known diketopiperazines,1,2,3,4-tetrahydro-2, 3-dimethyl-1,4-dioxopyrazino[1,2-a]indole (3), 1,2,3,4-tetrahydro-2-methyl-3-methylen e-1,4-dioxopyrazino[1,2-a]indole (4), 1,2,3,4-tetrahydro-2-methyl-1,3,4-trioxopyrazino[1,2-a] indole (5), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio)gliotoxin (11), didehydrobisdethiobis(methylthio)gliotoxin (12) and N-methyl-1H-indole-2-carboxamide (6).

Pseudaboydins A and B: novel isobenzofuranone derivatives from marine fungus Pseudallescheria boydii associated with starfish Acanthaster planci.

Two novel isobenzofuranone derivatives, pseudaboydins A (1) and B (2), along with five known compounds, including (R)-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5-hydroxybenzofuran (3), (R)-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5-methoxybenzofuran (4), 3,3'-dihydroxy-5,5'-dimethyldiphenyl ether (5), 3-(3-methoxy-5-methylphenoxy)-5-methylphenol (6) and (-)-regiolone (7), were isolated from the culture broth of the marine fungus, Pseudallescheria boydii, associated with the starfish, Acanthaster planci. Their structures were elucidated primarily based on NMR and MS data. The absolute configurations of 1-4 were determined by CD spectroscopy and single-crystal X-ray diffraction studies.

100-GHz DD-OFDM-RoF system over 150-km fiber transmission employing pilot-aided phase noise suppression and bit-loading algorithm.

This study extended the transmission distance of a 100-GHz DD-OFDM-RoF system through the reduction of chromatic dispersion-induced phase noise. The implementation of a pilot-aided phase noise suppression (PPNS) scheme enabled the transmission of distance-insensitive 16.97-Gbps QPSK OFDM over 0~150-km fiber and 2-m air transmission via a DFB laser with linewidth of 1~10-MHz.

Induced marine fungus Chondrostereum sp. as a means of producing new sesquiterpenoids chondrosterins I and J by using glycerol as the carbon source.

Chondrostereum sp., a marine fungus isolated from a soft coral Sarcophyton tortuosum, can yield hirsutane framework sesquiterpenoids. However, the metabolites profiles vary dramatically with the composition change of the culture media.

High spectral efficient W-band OFDM-RoF system with direct-detection by two cascaded single-drive MZMs.

W-band wireless transmission has attracted a lot of interest due to its wider available bandwidth (i.e. 75-110 GHz).

Trichodermaerin, a new diterpenoid lactone from the marine fungus Trichoderma erinaceum associated with the sea star Acanthaster planci.

Trichodermaerin (1), a novel diterpenoid lactone, together with the known compound, harziandione (2) were isolated from the culture broth of the fungus Trichoderma erinaceum associated with the sea star Acanthaster planci. Their structures were determined by analysis of the NMR and MS data. 1 was the Baeyer-Villiger monooxygenase catalyzed oxidation product of 2.

Hexaaqua-cobalt(II) 5,5'-(propane-1,3-diyldithio)bis-(1H-tetra-zole-1-acetate).

The asymmetric unit of the title complex, [Co(H(2)O)(6)](C(9)H(10)N(8)O(4)S(2)), contains one-half of a [Co(H(2)O)(6)](2+) cation and one-half of a 5,5'-(propane-1,3-diyldithio)bis-(1H-tetra-zole-1-acetate) (battp(2-)) anion. The Co(II) center is coordinated by six H(2)O mol-ecules in a distorted octa-hedral coordination environment. In the crystal structure, intra- and inter-molecular O-H⋯O and O-H⋯N hydrogen bonds link the cations and anions into a three-dimensional network.