Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, U...Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.展开更多
Since the first demonstration of sperm entry into the fertilized eggs of Mediterranean sea urchin Paracentrotus lividus by Hertwig(1876),enormous progress and insights have been made on this topic.However,the precise ...Since the first demonstration of sperm entry into the fertilized eggs of Mediterranean sea urchin Paracentrotus lividus by Hertwig(1876),enormous progress and insights have been made on this topic.However,the precise molecular mechanisms underlying fertilization are largely unknown.The two most dramatic changes taking place in the zygote immediately after fertilization are:(i) a sharp increase of intracellular Ca2+ that initiates at the sperm interaction site and traverses the egg cytoplasm as a wave,and(ii) the concomitant dynamic rearrangement of the actin cytoskeleton.Traditionally,this has been studied most extensively in the sea urchin eggs,but another echinoderm,starfish,whose eggs are much bigger and transparent,has facilitated experimental approaches using microinjection and fluorescent imaging methodologies.Thus in starfish,it has been shown that the sperm-induced Ca2+ increase in the fertilized egg can be recapitulated by several Ca2+ -evoking second messengers,namely inositol 1,4,5-trisphosphate(InsP3) ,cyclic ADP-ribose(cADPr) and nicotinic acid adenine dinucleotide phosphate(NAADP) ,which may play distinct roles in the generation and propagation of the Ca2+ waves.Interestingly,it has also been found that the dynamic rearrangement of the actin cytoskeleton in the fertilized eggs plays pivotal roles in guiding monospermic sperm entry and in the fine modulation of the intracellular Ca2+ signaling.As it is well known that Ca2+ regulates the structure of the actin cytoskeleton,our finding that Ca2+ signaling can be reciprocally affected by the state of the actin cytoskeleton raises an intriguing possibility that actin and Ca2+ signaling may form a'positive feedback loop'that accelerates the downstream events of fertilization.Perturbation of the cortical actin networks also inhibits cortical granules exocytosis.Polymerizing actin bundles also compose the'acrosome process,'a tubular structure protruding from the head of fertilizing sperm. Hence,actin,which is one of the most strictly conserved proteins in e展开更多
A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identified to be sodium 6α-O-{β-D-f...A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identified to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D- quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyranosyl}-5α-pregn-9(11)-en- 20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.展开更多
A new polyhydroxysteroidal glycoside, （20R,24R）-16-O-（4-O-methyl-2-acetamido-2-deoxy-β-D-galactopyranosyl）-24-ethyl- 5α-cholest-8（14）-en-313,613,713,16α-tetrol （anthenoside A, 1）, was isolated from the star...A new polyhydroxysteroidal glycoside, （20R,24R）-16-O-（4-O-methyl-2-acetamido-2-deoxy-β-D-galactopyranosyl）-24-ethyl- 5α-cholest-8（14）-en-313,613,713,16α-tetrol （anthenoside A, 1）, was isolated from the starfish Anthenea chinensis. Its structure was elucidated by extensive spectral analysis and chemical evidences. 1 exhibited significant cytotoxicity against human tumor K-562, BEL-7402 and U87MG cells.展开更多
A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the ada...A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the adaptability of soft robots on complex surfaces is still a challenging problem.To this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm structure.Inspired by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation layers.We design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide suction.The soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the substrate.Variable stiffness layers achieve stiffness changes by the principle of line blocking.The Central Pattern Generator theory is introduced to coordinately control the multiple feet of the robot.After experiments,we verify the adaptability of the soft robot to curved surfaces.The research may provide a reference for the design and development of crawling soft robots on complex surfaces.展开更多
文摘Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.
文摘Since the first demonstration of sperm entry into the fertilized eggs of Mediterranean sea urchin Paracentrotus lividus by Hertwig(1876),enormous progress and insights have been made on this topic.However,the precise molecular mechanisms underlying fertilization are largely unknown.The two most dramatic changes taking place in the zygote immediately after fertilization are:(i) a sharp increase of intracellular Ca2+ that initiates at the sperm interaction site and traverses the egg cytoplasm as a wave,and(ii) the concomitant dynamic rearrangement of the actin cytoskeleton.Traditionally,this has been studied most extensively in the sea urchin eggs,but another echinoderm,starfish,whose eggs are much bigger and transparent,has facilitated experimental approaches using microinjection and fluorescent imaging methodologies.Thus in starfish,it has been shown that the sperm-induced Ca2+ increase in the fertilized egg can be recapitulated by several Ca2+ -evoking second messengers,namely inositol 1,4,5-trisphosphate(InsP3) ,cyclic ADP-ribose(cADPr) and nicotinic acid adenine dinucleotide phosphate(NAADP) ,which may play distinct roles in the generation and propagation of the Ca2+ waves.Interestingly,it has also been found that the dynamic rearrangement of the actin cytoskeleton in the fertilized eggs plays pivotal roles in guiding monospermic sperm entry and in the fine modulation of the intracellular Ca2+ signaling.As it is well known that Ca2+ regulates the structure of the actin cytoskeleton,our finding that Ca2+ signaling can be reciprocally affected by the state of the actin cytoskeleton raises an intriguing possibility that actin and Ca2+ signaling may form a'positive feedback loop'that accelerates the downstream events of fertilization.Perturbation of the cortical actin networks also inhibits cortical granules exocytosis.Polymerizing actin bundles also compose the'acrosome process,'a tubular structure protruding from the head of fertilizing sperm. Hence,actin,which is one of the most strictly conserved proteins in e
文摘A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identified to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D- quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyranosyl}-5α-pregn-9(11)-en- 20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.
基金the National Natural Science Foundation of China(No.20502035)the National High-Tech Research and Development Project(No.2006AA09Z423)
文摘A new polyhydroxysteroidal glycoside, （20R,24R）-16-O-（4-O-methyl-2-acetamido-2-deoxy-β-D-galactopyranosyl）-24-ethyl- 5α-cholest-8（14）-en-313,613,713,16α-tetrol （anthenoside A, 1）, was isolated from the starfish Anthenea chinensis. Its structure was elucidated by extensive spectral analysis and chemical evidences. 1 exhibited significant cytotoxicity against human tumor K-562, BEL-7402 and U87MG cells.
文摘A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the adaptability of soft robots on complex surfaces is still a challenging problem.To this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm structure.Inspired by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation layers.We design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide suction.The soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the substrate.Variable stiffness layers achieve stiffness changes by the principle of line blocking.The Central Pattern Generator theory is introduced to coordinately control the multiple feet of the robot.After experiments,we verify the adaptability of the soft robot to curved surfaces.The research may provide a reference for the design and development of crawling soft robots on complex surfaces.
