Beschreibung: Three new pregnane alkaloids, pachystermine C ( 1 ), pachysanamine A ( 2 ), and pachysanamine B ( 3 ), together with four known ones, pachystermine B ( 4 ), pachysamine A ( 5 ), (20 S )-20-(dimethylamino)-16 α -hydroxy-3 β -(3’ α -isopropyl)-lactam-5 α -pregn-4-one ( 6 ), E -salignone ( 7 ), were isolated from Pachysandra terminalis . The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines, some of the compounds showed stronger cytotoxicity for the test cell lines, especially compounds 2 , 3 , and 7 . This article is protected by copyright. All rights reserved.

Beschreibung: The planar membrane reactor configuration was explored for partial oxidation of methane to syngas. A supported membrane composed of yttria-stabilized zirconia and La 0.8 Sr 0.2 Cr 0.5 Fe 0.5 O 3-δ was sealed to a stainless holder, and a Ni/Al 2 O 3 catalyst bed was placed under the membrane plane with a small slit between them. This reactor configuration would facilitate the POM reaction via oxidation-reforming mechanism: the oxidation reaction occurring at the membrane surface and the reforming reaction taking place in the catalyst bed. At 800°C and a methane feed rate of 32 ml min −1 , the reactor attained methane throughput conversion over 90%, CO and H 2 selectivity both over 95%,and an equivalent oxygen permeation rate 1.4 ml cm −2 min −1 .The membrane and catalyst remained intact after the POM testing. The planar membrane reactor configuration explored in the present study may lead to the development of a compact reactor for syngas production. This article is protected by copyright. All rights reserved.

Beschreibung: The nucleophilic substitution reactions of carboxylic esters (R 1 COOR 2 ) follow 2 possible mechanisms, namely, stepwise mechanism and concerted mechanism. The reaction mechanism is affected by the structures of the nonleaving group (NLG, ie, R 1 ), the leaving group (LG, ie, OR 2 ) of carboxylic esters, and the nucleophiles (Nu). The traditional approach for the determination of reaction mechanism by dynamic experiments is not only laborious and time consuming but also only applicable for the situation with single structural factor variation. Benefiting from the ample existing kinetic data, this article aimed to construct a molecular structure-based classification model by support vector machine (SVM). The polarizability effect index of the NLG (PEI(NLG)), the p K a of the conjugate acid of the LG (p K a (LG)), and the p K a of the conjugate acid of the Nu (p K a (Nu)) were used to characterize the structural information of the 3 influencing factors, respectively. On the basis of these structural descriptors, the SVM classification model was established for the reaction mechanisms of 225 nucleophilic substitution reactions in the training set. The total prediction accuracy of 99.11% was achieved by 5-fold cross validation. Then the reaction mechanisms of 56 reactions in test set A were predicted by this SVM model, and the prediction accuracy was up to 98.21%. Furthermore, test set B consisting of 24 reactions were used as another external data set for prediction, where the reaction mechanisms were controversially reported by different studies. The prediction results of test set B by the SVM model built in this article were amazingly consistent with the conclusions drawn by Um et al. A support vector machine classification model for the nucleophilic substitution reaction mechanisms of carboxylic esters was built based on 3 structural descriptors including PEI(NLG), p K a (LG), and p K a (Nu), which are not only simple to be calculated but also of clear physical meaning. The total prediction accuracy of 99.11% was achieved for the training set and 98.21% for the test set. This study provided a theoretical support for the understanding and recognition of reaction mechanism of nucleophilic substitution based on the molecular structure.

Beschreibung: A total of 1502 samples, including feces of sheep (793) and cattle (348), pasture soil (118), dung compost (147) and barn soil (96), were examined between October 2012 and August 2014 to discover potential strains of nematophagous fungi for the biological control of livestock-parasitic nematodes. These samples were collected from 87 sites located in 48 counties of 20 provinces (autonomous regions/municipalities) of China. Fungi were identified down to a species level. Four hundred and seventy-seven isolates, which were distributed in 8 genera and 28 taxa, were identified as nematophagous fungi. Nematode-trapping fungi included 17 species and one unidentified species of Arthrobotrys , two of Dactylella , Drechslerella dactyloides , and Duddingtonia flagrans . Five identified species and two unidentified species of endoparasitic fungi were isolated. The predominant species from all regions were Arthrobotrys oligospora , followed by Arthrobotrys musiformis , Arthrobotrys ( Monacrosporium ) thaumasiun , and Arthrobotrys ( Monacrosporium ) microscaphoides . Species with adhesive networks were the most frequently isolated. Among the endoparasitic fungi, Podocrella harposporifera ( Harposporium anguillulae ) was the most common species, followed by Harposporium lilliputanum and Harposporium arcuatum . Based on Shannon diversity index, the diversity levels of nematophagous fungi were relatively higher in samples associated with cattle, barn soil, and subtropical monsoon climate zone. Three species isolated from this study, namely, Duddingtonia flagrans , Arthrobotrys salina ( Monacrosporium salinum ), and Arthrobotrys oligospora var. sarmatica , are newly recorded in China, and 20 species (including one unidentified species) are newly recorded in sheep and cattle barn soils worldwide.