Two new steroidal glycosides and one polyhydroxylated sterol were isolated from the soft coral Cladiella sp. by HPLC fractionation. The animal material was collected from Sanya bay, Hainan province, China. On the basi...Two new steroidal glycosides and one polyhydroxylated sterol were isolated from the soft coral Cladiella sp. by HPLC fractionation. The animal material was collected from Sanya bay, Hainan province, China. On the basis of spectroscopic analysis and chemical conversion, their chemical structures were elucidated as pregn-5,20-dien-3β-ol-3-O-α-L-fucopyranoside(1), pregn-5,20-dien-3β-ol-3-O-β-D-xylopyranoside(2) and (22E,24R)-ergost-7,22-dien-3β,5α,6β-triol(3). Compounds 1 and 2 are new compounds.展开更多
Soft corals yield a wide variety of terepenes, steroids and glycosides. The soft coral Cladiella krempfi has been studied by Christopher, and Bheemasankara and five cembanoid diterpenes have been obtained. In our cont...Soft corals yield a wide variety of terepenes, steroids and glycosides. The soft coral Cladiella krempfi has been studied by Christopher, and Bheemasankara and five cembanoid diterpenes have been obtained. In our continuing search to discover the bioactive substances from Chinese soft coral, a species of the soft coral Cladiella krempfi collected from Weizhou Island, Guangxi Province were investigated. Two steroidal glycosides 1 and 2 were first isolated from the ethanol extract. On the basis of the spectroscopic methods their structures were established as 3-O-[-D-arabinopyranosyl]-pregn-5,20-dien-3β-ol(1) and \{4-O-[β-D-arabinopyranosyl]-pregn-20-en-3β,4α-diol(2)\}. Steroidal glycosides were first found from this species of soft coral. Compound 1 was a new compound. Compound 2 was obtained from the South China Sea soft coral, Lobophyton sp. Bioassay showed that compound 2 displayed cytotoxic against human Hep-G2 and Cne2 cell lines in vitro with IC 50 values 27.9, 14.3 μg/mL respectively.展开更多
This paper studies the software scenario testing, which is commonly used in black-box testing at present. In the paper, the workflow model based on task-driven, which is very common in scenario testing, is analyzed. A...This paper studies the software scenario testing, which is commonly used in black-box testing at present. In the paper, the workflow model based on task-driven, which is very common in scenario testing, is analyzed. According to test adequacy criteria in scenario testing, the model is designed to correspond test cases in the light of logic block(LB). The final test cases that conform to the test adequacy criteria can be obtained through test case combination and test case reduction. In the last part of the paper, example of actual workflow is to design the efficient test case. Therefore the method is proved to be effective.展开更多
Laevistrombus canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L...Laevistrombus canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L. canarium at different ontogenetic stages （juveniles, sub-adults and adults） from Merambong shoals, Malaysia. Field observations on feeding activity were conducted, followed by detailed laboratory analysis on the stomach content. Five-minutes observations on randomly selected individuals were conducted at the field sampling site and their feeding activities were recorded with reference to age stage. Various shell sizes from each ontogenetic stage were randomly collected and quickly anaesthetized with ice and preserved in 10% formalin before being transported to the laboratory for stomach content analyses. Field observations showed that L. canarium mainly grazed on epiphytes occurring on seagrass （46.67%）, followed by sediment surface （40%） and epiphytes occurring on macroalgae （13.33%）. Stomach content analyses showed a significant difference （P〈0.05） in gastro-somatic index （Gasi） between the juveniles （0.39±0.05）, sub-adults （0.68±0.09） and adults （0.70±0.05） （P〈0.05）. Food items found in the conch stomach include diatoms, detritus, foraminifera, seagrass and macroalgae fragments, sand particles and shell fragments. The Index of Relative Importance （%IRI） indicates three main types of food dominated the three ontogenetic stages namely diatoms, sand particles and detritus. However, no significant difference （P〉0.05） was detected between the three main food items （diatoms, sand particles and detritus） among the ontogenetic stages. Therefore, feeding activity revealed the role of the dog conch in the marine food network. While, classification of the types of food consumed by L. canarium through stomach content analysis determines the particular position of the gastropod in the food chain. Further studies are needed to provide a better insight between trophic relationships ofL. eanarium with marine ecosystem.展开更多
文摘Two new steroidal glycosides and one polyhydroxylated sterol were isolated from the soft coral Cladiella sp. by HPLC fractionation. The animal material was collected from Sanya bay, Hainan province, China. On the basis of spectroscopic analysis and chemical conversion, their chemical structures were elucidated as pregn-5,20-dien-3β-ol-3-O-α-L-fucopyranoside(1), pregn-5,20-dien-3β-ol-3-O-β-D-xylopyranoside(2) and (22E,24R)-ergost-7,22-dien-3β,5α,6β-triol(3). Compounds 1 and 2 are new compounds.
文摘Soft corals yield a wide variety of terepenes, steroids and glycosides. The soft coral Cladiella krempfi has been studied by Christopher, and Bheemasankara and five cembanoid diterpenes have been obtained. In our continuing search to discover the bioactive substances from Chinese soft coral, a species of the soft coral Cladiella krempfi collected from Weizhou Island, Guangxi Province were investigated. Two steroidal glycosides 1 and 2 were first isolated from the ethanol extract. On the basis of the spectroscopic methods their structures were established as 3-O-[-D-arabinopyranosyl]-pregn-5,20-dien-3β-ol(1) and \{4-O-[β-D-arabinopyranosyl]-pregn-20-en-3β,4α-diol(2)\}. Steroidal glycosides were first found from this species of soft coral. Compound 1 was a new compound. Compound 2 was obtained from the South China Sea soft coral, Lobophyton sp. Bioassay showed that compound 2 displayed cytotoxic against human Hep-G2 and Cne2 cell lines in vitro with IC 50 values 27.9, 14.3 μg/mL respectively.
基金National Torch Project, China ( No. 2009GH510068 )National High-Tech R & D Program of China ( 863 ) ( No.2007AA010401)
文摘This paper studies the software scenario testing, which is commonly used in black-box testing at present. In the paper, the workflow model based on task-driven, which is very common in scenario testing, is analyzed. According to test adequacy criteria in scenario testing, the model is designed to correspond test cases in the light of logic block(LB). The final test cases that conform to the test adequacy criteria can be obtained through test case combination and test case reduction. In the last part of the paper, example of actual workflow is to design the efficient test case. Therefore the method is proved to be effective.
基金Supported by the Ministry of Science,Technology and Innovation,Malaysia (MOSTI) through UKM Fundamental Research Grant(No.FRGS/2/2014/STWN10/UKM/02/1)the Centre for Research and Innovation Management Grant(CRIM)(No.AP-2012-013)
文摘Laevistrombus canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L. canarium at different ontogenetic stages （juveniles, sub-adults and adults） from Merambong shoals, Malaysia. Field observations on feeding activity were conducted, followed by detailed laboratory analysis on the stomach content. Five-minutes observations on randomly selected individuals were conducted at the field sampling site and their feeding activities were recorded with reference to age stage. Various shell sizes from each ontogenetic stage were randomly collected and quickly anaesthetized with ice and preserved in 10% formalin before being transported to the laboratory for stomach content analyses. Field observations showed that L. canarium mainly grazed on epiphytes occurring on seagrass （46.67%）, followed by sediment surface （40%） and epiphytes occurring on macroalgae （13.33%）. Stomach content analyses showed a significant difference （P〈0.05） in gastro-somatic index （Gasi） between the juveniles （0.39±0.05）, sub-adults （0.68±0.09） and adults （0.70±0.05） （P〈0.05）. Food items found in the conch stomach include diatoms, detritus, foraminifera, seagrass and macroalgae fragments, sand particles and shell fragments. The Index of Relative Importance （%IRI） indicates three main types of food dominated the three ontogenetic stages namely diatoms, sand particles and detritus. However, no significant difference （P〉0.05） was detected between the three main food items （diatoms, sand particles and detritus） among the ontogenetic stages. Therefore, feeding activity revealed the role of the dog conch in the marine food network. While, classification of the types of food consumed by L. canarium through stomach content analysis determines the particular position of the gastropod in the food chain. Further studies are needed to provide a better insight between trophic relationships ofL. eanarium with marine ecosystem.
