37 research outputs found
Bioactivities of Lyngbyabellins from Cyanobacteria of Moorea and Okeania Genera
Cyanobacteria are reported as rich sources of secondary metabolites that provide biological activities such as enzyme inhibition and cytotoxicity. Ten depsipeptide derivatives (lyngbyabellins) were isolated from a Malaysian Moorea bouillonii and a Red Sea Okeania sp.: lyngbyabellins G (1), O (2), P (3), H (4), A (7), 27-deoxylyngbyabellin A (5), and homohydroxydolabellin (6). This study indicated that lyngbyabellins displayed cytotoxicity, antimalarial, and antifouling activities. The isolated compounds were tested for cytotoxic effect against human breast cancer cells (MCF7), for antifouling activity against Amphibalanus amphitrite barnacle larvae, and for antiplasmodial effect towards Plasmodium falciparum. Lyngbyabellins A and G displayed potent antiplasmodial effect against Plasmodium, whereas homohydroxydolabellin showed moderate effect. For antifouling activity, the side chain decreases the activity slightly, but the essential feature is the acyclic structure. As previously reported, the acyclic lyngbyabellins are less cytotoxic than the corresponding cyclic ones, and the side chain increases cytotoxicity. This study revealed that lyngbyabellins, despite being cytotoxic agents as previously reported, also exhibit antimalarial and antifouling activities. The unique chemical structures and functionalities of lyngbyabellin play an essential role in their biological activities
ã¿ããžãããžãããããªã¹å¹Œçã«å¯Ÿããä»çé»å®³ç©è³ªã«é¢ããç 究
ãããžããé¡ãã€ã¬ã€é¡ãã¯ãããšããæµ·æŽä»ççç©ã¯ãçºé»æã®åæŸæ°Žè·¯ãè¹åºãé€æ®æœèšãªã©ã«ä»çããŠå€å€§ã®è¢«å®³ãäžããŠããããããã®çç©ã®é²é€ã«ã¯ãåŸæ¥ææ©ã¹ãºååç©ãäºé
žåé
ãªã©ã®ééå±ãå«ãé²æ±å¡æãäž»ã«äœ¿ãããŠãããææ©ã¹ãºç³»é²æ±å¡æã¯ãåªããé²æ±å¹æãæããããšããåºãçšããããŠããããå€ãã®æµ·ç£çç©ã«å¯ŸããŠæ¯æ§ã瀺ãããšãå€æãããããæãåœã§ã¯1992幎ã«è£œé ããã³äœ¿çšãçŠæ¢ãšãªããäžççã«ã䜿çšãçŠæ¢ããæ¹åã§åè°ãé²ããããŠãããåæ§ã«ãäºé
žåé
ç³»å¡æãæµ·æŽç°å¢ã«äžãã圱é¿ãæžå¿µãããŠãããäžæ¹ãææ©ã¹ãºååç©ã®ä»£æ¿åãšããŠç»å ŽããIrgarol1051ãªã©ã®ãã€ãªãµã€ãã«ã€ããŠããåæ§ãªåé¡ãçããŠããããã®æ§ãªç¶æ³ãããããããç°å¢ã«åªããé²æ±å€ã®éçºãç·æ¥ã®èª²é¡ãšãªã£ãŠããã//ãããã§æ¬ç 究ã§ã¯ãç°å¢ãžã®è² è·ã®å°ãªãé²æ±å€ãéçºããããšãç®çãšããæµ·æŽç¡èæ€åç©æœåºæ¶²ã«ã€ããŠããžãã幌çã®ä»çé»å®³è©Šéšãè¡ã£ãŠæµ®ãã³äžãã£ãææãªæŽ»æ§ããã€æµ·ç¶¿ããä»çé»å®³ç©è³ªã®æ¢çŽ¢ãè©Šã¿ããšãšãã«ãæ¢ã«æå¹ãªæŽ»æ§ãèªããããŠãã海綿ç±æ¥ã®3-isocyanotheonellineããªãŒãååç©ãšããŠ59çš®é¡ã®é¡çžäœãåæããŠä»çé»å®³æŽ»æ§ãè©äŸ¡ããããããŠãææãªæŽ»æ§ãèªããããååç©ã®äžãããæ¯èŒçå®äŸ¡ã«åæã§ãã2ã€ã®ååç©ã«ã€ããŠè©Šéšå¡æãäœæããæµ·å浞挬詊éšã«ããå¹æãå€å®ããããã®æŠèŠã¯ä»¥äžã®éãã§ããã//1.海綿ããã®æ°èŠä»çé»å®³ç©è³ªã®æ¢çŽ¢//ãå
ãã海綿ããã€ãã³ã±ã ã·ãªã©åèš118çš®é¡ã®ç¡èæ€åç©ã®ã¡ã¿ããŒã«æœåºç©ã察象ã«ãã¿ããžãããžãããããªã¹å¹Œçã«å¯Ÿããä»çé»å®³æŽ»æ§ã調ã¹ãããã®çµæã86çš®é¡ã100ÎŒg/mlã®æ¿åºŠã§ãããªã¹å¹Œçã®ä»çã80%以äžé»å®³ããããã®ãã¡ã13çš®é¡ã¯æ»äº¡ç15%以äžã®ææãªæŽ»æ§ã瀺ãããç¹ã«ãç±æµ·ã§æ¡éãã海綿Acanthella cavernosaã¯ãæ¬ç 究ã®ç®çã«åèŽãã掻æ§(ä»çé»å®³ç100%ãæ»äº¡ç0%)ã瀺ããã®ã§ã掻æ§æåã®åé¢ãšåå®ãè©Šã¿ãã//ãåçµæµ·ç¶¿(150g)ããšã¿ããŒã«ã§æœåºåŸãä»çé»å®³æŽ»æ§ãææšã«æº¶åªåç»ãããã³ã·ãªã«ã²ã«ãã©ãã·ã¥ã¯ãããã°ã©ãã£ãŒã«ä»ããåŸãODS-HPLCã2åç¹°ãè¿ããä»çé»å®³æŽ»æ§ã瀺ã3.9mgã®æ°èŠååç©1ãš0.7mgã®æ¢ç¥ååç©T-cadinol(2)ãåé¢ããã//ãæ°èŠååç©1ã®åååŒãã1HNMRã13CNMRããã³FABMSããŒã¿ããC16H27NOãšæ±ºå®ããããŸãã1HNMRãš13CNMRã¹ãã¯ãã«ããããã«ã ã¢ããåºã®ååšã瀺åããããããã«ãåçš®2次å
NMRã¹ãã¯ãã«ã®è©³çŽ°ãªè§£æã«ãããã»ã¹ããã«ãã³4-cadineneã®10äœã«ãã«ã ã¢ããåºãçµåããå¹³é¢æ§é ããã€ãã®ãšæšå®ããããããã§ã1ãp-TsCl/pyã§åŠçãããšããã10-ã€ãœã·ã¢ãäœãåŸãããããã®ååç©ã®1HNMRãš13CNMRã¹ãã¯ãã«ããã³æå
床ã¯ãæ¢ç¥ã®10-isocyano-4-cadineneã®ãããšå®å
šã«äžèŽãããããªãã¡ãååç©1ã10-formamido-4-cadineneãšæ±ºå®ããã10-formamido-4-cadinene(1)ã¯ãã¿ããžãããžãããããªã¹å¹Œçã«å¯ŸããŠEC500.50ÎŒg/mlã®ä»çé»å®³æŽ»æ§ã瀺ãããã10.0ÎŒg/mlã®æ¿åºŠã§ã¯å
šãŠã®å¹Œçãæ»äº¡ãããäžæ¹ãT-cadinol(2)ã®EC50å€ã¯0.53ÎŒg/mlã§ããã30.0ÎŒg/mlã§ã幌çã«æ¯æ§ãèŠãããªãã£ãããšãããææãªé²æ±å€åè£ãšèããããã//2.ã€ãœã·ã¢ãããã³é¡çžååç©ã®åæããã³ä»çé»å®³æŽ»æ§//ã海綿ç±æ¥ã®3-isocyanotheonelline(3)ã¯ãã¿ããžãããžãããããªã¹å¹Œçã«å¯ŸããŠEC500.13ÎŒg/mlã®ä»çé»å®³æŽ»æ§ã瀺ãããæ¯æ§ã匱ã(LD50>100ÎŒg/ml)ã®ã§ãææãªé²æ±å€åè£ãšèãããããããã§ãæ¬ååç©ãã¢ãã«ååç©ãšããŠãåçš®é¡çžäœãåæããŠä»çé»å®³æŽ»æ§ãè©äŸ¡ãããå
ãã3-isocyanotheonellineãå«ã4ã€ã®ç°æ§äœãåæãããšãšãã«ãåŽééšåãéå
ãããã®ãä»ã®å®èœåºã§çœ®ãæããååç©ãåæããã次ã«ãã·ã¯ããããµã³ç°ãããæ±ãæããã§ãã«åºãžå€æããããã«åŽééšåãå€æŽãããã®ããããã¯ã€ãœã·ã¢ãåºãä»ã®å®èœåºã«å€æããååç©ãåæãããããã«ãããç°¡åãªæ§é ã®é²æ±å€éçºãç®æããŠãçŽéã€ãœã·ã¢ãååç©ãåæããããã®ããã«ããŠãåèš59çš®é¡ã®ååç©ãåæãããããã®ãããªã¹å¹Œçã«å¯Ÿããä»çé»å®³æŽ»æ§ãšæ¯æ§ãè©äŸ¡ããã//ãåæãã3ã€ã®ç°æ§äœã¯ã3-isocyanotheonellineãšã»ãŒåçã®é»å®³æŽ»æ§ã瀺ããããŸããåŽééšåãã«ã«ããã«åºãå«ãæ§é ã«å€ããååç©ã¯ãéåžžã«åŒ·ãä»çå¿é¿æŽ»æ§ã瀺ãããã€æž¬å®ããç¯å²ã§ã¯é¡èãªæ¯æ§ã瀺ããªãã£ããç¹ã«ãtrans-4-isocyano-4-methylcyclohexyl acetate(4)ã¯ãåæããååç©ã®äžã§æã匷ã掻æ§(EC500.0094ÎŒg/ml)ã瀺ããã//ãåæ§ã«ã3-isocyanotheonellineã®ã·ã¯ããããµã³ç°ããã§ãã«åºãžå€æãã4-[(E,E)-1,5-dimethl-hexa-1,3-dienyl]isocyano benzene(5)ã匷ã掻æ§ã瀺ããããŸãã5ã®åŽééšåããã³ãžã«ãªãã·ã«åºãžãšå€æãã4-benzyloxyphenyl isocyanide(6)ã匷ãä»çé»å®³æŽ»æ§ã瀺ããããç¡«é
žé
ãšã»ãŒåçã®æ¯æ§(LD503.0ÎŒg/ml)ã瀺ãããäžæ¹ã6ã®ã€ãœã·ã¢ãåºãã·ã¢ãåºãã¢ããåºãããã¯ã«ã«ããã·ã«åºãªã©ã«å€æããååç©ã¯ãã»ãšãã©æŽ»æ§ã瀺ãããã€ãœã·ã¢ãåºãä»çé»å®³æŽ»æ§ã®çºçŸã«éèŠãªåœ¹å²ãæããŠããããšã瀺åãããããŸããã€ãœã·ã¢ãåºãã¢ã»ãã¢ããåºãžå€æããN-(4-hexylphenyl)acetamide(7)ã¯ãå€å°æŽ»æ§ãèœã¡ããã®ã®ãæ¯æ§ãäœãããã€æ¯èŒçç°¡åã«åæãã§ãããããé²æ±å€ãšããŠææãšèããããã//ãçŽéã€ãœã·ã¢ãååç©ã¯ãå
šãŠé¡èãªä»çé»å®³æŽ»æ§(EC500.046-1.90ÎŒg/ml)瀺ãããã€æ¯æ§ãç¡«é
žé
ããããªã匱ãã£ããç¹ã«ã1,1-dimethyl-10-undecyl isocyanide(8)ãš1,1-dimethyl-10-phenyltioldecyl isocyanide(9)ã¯åŒ·ã掻æ§ã瀺ããããç¡«é
žé
ã®LD50å€ã®çŽ10åã§ãã30ÎŒg/mlã§ãæ¯æ§ãèªããããªãã£ãã//3.è©Šäœå¡æã®ãã£ãŒã«ãè©Šéš//ãåæããååç©ã®äžããã匷ãä»çé»å®³æŽ»æ§ãšåŒ±ãæ¯æ§ããã¡ããã€æ¯èŒçå®äŸ¡ã«åæã§ããååç©ã®N-(4-hexylphenyl)acetamide(7)ãš1,1-dimethyl-10-undecyl isocyanide(8)ããããã300gåæããè©Šäœå¡æãäœæããŠå®æµ·å浞挬詊éšãè¡ã£ãã//ãè©Šäœå¡æã¯ã15%ã®ååç©7ãããã¯8ãã«ã«ãã³é
žç³»ã¢ã¯ãªã«ããªããŒãäž»æåã®æš¹èã«æ··åããŠäœæãããå¡©åããã«æ¿(25Ã25cm)ã3çåããåžè²©ã®äºé
žåé
å¡æãäžå€®ã«6Ã25cmã®é¢ç©ã§å¡åžããããã«2çš®é¡ã®è©Šäœå¡æãäž¡åŽã«ãããã7.5Ã25cmã®é¢ç©ã§å¡åžããããããå®®åçå¿æŽ¥å·çºã®æŒæž¯ã®å»è¹ããæ°Žæ·±0.5mã®äœçœ®ã«2003幎8æ30æ¥ã11æ27æ¥ã®çŽ3ã¶æéåäžããçŽ1ãµææ¯ã«èŠ³å¯ãããäžæ¹ãæ±äº¬æ¹Ÿã§ã¯2003幎10æ16æ¥ã12æ9æ¥ã®çŽ2ã¶æéããå°å Žã®å²žå£ã®æ干朮ææ°Žæ·±çŽ1mã®äœçœ®ã«è©Šéšæ¿ãèšçœ®ããŠåæ§ã«èŠ³å¯ãè¡ã£ãã//ããã®çµæãå®®åçã«èšçœ®ããä»çæ¿ã§ã¯ãå¡è£
ããŠããªãè£é¢ã«çŸ€äœãã€ãã³ã±ã ã·ããããè«ãªã©ã®å€§åä»ççç©ãäžé¢ã«ä»çããŠããã®ã芳å¯ãããããè©Šéšå¡æé¢ã¯ãããè«ã®èµ°æ ¹ãšä»ççªè»ã®ä»çãèŠããããã®ã®ã3ãµæåŸã§ãæå¹ãªé²æ±æ§èœãã¿ãããããŸããæ±äº¬æ¹Ÿã«èšçœ®ããæ¿ã«ã¯ãåäœãã€ãšããžããã®ä»çãèŠãããããå¡è£
é¢ãžã®ãã€ã®ä»çã¯èŠããããããžããã®ä»çæ°ãç¡å¡è£
é¢ãšæ¯èŒããŠææã«å°ãªãã£ãã以äžã®ããšããããããã®æµ·åã«ãããŠããäºé
žåé
å¡æãšæ¯èŒãããšããé²æ±æ§èœãå£ããã®ã®ãè©Šäœå¡æã¯é¡èãªé²æ±å¹æãæãããã®ãšå€æãããã//ã以äžæ¬ç 究ã§ã¯ãç°å¢ã«åªããé²æ±å€ã®éçºãç®çã«ãæµ·æŽå€©ç¶ç©è³ªã®æ€çŽ¢ããã³ååŠåæã«ããåè£ååç©ã®æ¢çŽ¢ãè¡ã£ãçµæãä»çé»å®³ã匷ãããã€æ¯æ§ã匱ãæ°çš®ã®ã€ãœã·ã¢ãååç©ãåµé ããããšãã§ãããããã«ããã£ãŒã«ãè©Šéšã«ãããŠããããã®ååç©ãæå¹ãªããšã蚌æãããã€ãœã·ã¢ãåºãå«ãååç©ã®æå¹æ§ã瀺ãããšãã§ããããããã®ç¥èŠã¯ç°å¢è² è·ã®å°ãªãé²æ±å¡æã®éçºã«å€§ããªè²¢ç®ããããã®ãšæããããUniversity of Tokyo (æ±äº¬å€§åŠ
Thiomycalolides:Â New Cytotoxic Trisoxazole-Containing Macrolides Isolated from a Marine Sponge Mycale
Long-term in situ observation of barnacle growth on soft substrates with different elasticity and wettability
In this paper, settlement, metamorphosis, and long term growth of barnacles on soft substrates with a wide elasticity range (modulus 0.01-0.47 MPa) as well as with the variation of wettability were investigated for the first time in vitro, in the laboratory environment. Tough double-network (DN) hydrogels and polydimethylsiloxane (PDMS) were used as the soft hydrophilic substrates and hydrophobic substrates, respectively, and polystyrene (PS), a hard and hydrophobic substrate, was used as a control. It was observed that 1) the initial settlement and metamorphosis of cyprid larvae dramatically increase with the substrate elastic modulus while does not show an explicit dependence on the substrate wettability; 2) the growth rate of barnacles on both DN gels and PDMSs does not show an explicit dependence on the elasticity of the soft substrates, while it shows a slightly higher value on the hydrophobic PDMSs than on the hydrophilic DN gels; 3) the growth rate on these soft substrates is explicitly lower than that on the rigid PS substrate at the late stage of the growth; 4) the "self-release" phenomenon of barnacles was observed for the PDMS substrate with modulus higher than 0.01 MPa. Based on these observations, the antifouling effects of the soft substrates on barnacles were discussed
Prolonged morphometric study of barnacles grown on soft substrata of hydrogels and elastomers
A long-term investigation of the shell shape and the basal morphology of barnacles grown on tough, double-network (DN) hydrogels and polydimethylsiloxane (PDMS) elastomer was conducted in a laboratory environment. The elastic modulus of these soft substrata varied between 0.01 and 0.47MPa. Polystyrene (PS) (elastic modulus, 3 GPa) was used as a hard substratum control. It was found that the shell shape and the basal plate morphology of barnacles were different on the rigid PS substratum compared to the soft substrata of PDMS and DN hydrogels. Barnacles on the PS substratum had a truncated cone shape with a flat basal plate while on soft PDMS and DN gels, barnacles had a pseudo-cylindrical shape and their basal plates showed curvature. In addition, a large adhesive layer was observed under barnacles on PDMS, but not on DN gels. The effect of substratum stiffness is discussed in terms of barnacle muscle contraction, whereby the relative stiffness of the substratum compared to that of the muscle is considered as the key parameter
Larval development and settlement of a whale barnacle
Larval development and settlement of whale barnacles have not previously been described, unlike intertidal barnacles. Indeed, the mechanisms of the association between barnacles and whales have not been studied. Here we describe the larval development and settlement of the whale barnacle, Coronula diadema, and possible involvement of a cue from the host in inducing larval settlement. Eight-cell stage embryos were collected from C. diadema on a stranded humpback whale, incubated in filtered seawater for 7 days, and nauplius larvae hatched out. When fed with Chaetoceros gracilis, the nauplii developed to stage VI, and finally metamorphosed to the cypris stage. The larval development looked similar to that of intertidal barnacles with planktotrophic larval stages. The cyprids did not settle in normal seawater, but did settle in polystyrene Petri dishes when incubated in seawater with a small piece of skin tissue from the host whale. This strongly suggests the involvement of a chemical cue from the host whale tissue to induce larval settlement
Design, Synthesis, and Antifouling Activity of Glucosamine-Based Isocyanides
Biofouling, an undesirable accumulation of organisms on sea-immersed structures such as ship hulls and fishing nets, is a serious economic issue whose effects include oil wastage and clogged nets. Organotin compounds were utilized since the 1960s as an antifouling material; however, the use of such compounds was later banned by the International Maritime Organization (IMO) due to their high toxicity toward marine organisms, resulting in masculinization and imposex. Since the ban, there have been extensive efforts to develop environmentally benign antifoulants. Natural antifouling products obtained from marine creatures have been the subject of considerable attention due to their potent antifouling activity and low toxicity. These antifouling compounds often contain isocyano groups, which are well known to have natural antifouling properties. On the basis of our previous total synthesis of natural isocyanoterpenoids, we envisaged the installation of an isocyano functional group onto glucosamine to produce an environmentally friendly antifouling material. This paper describes an effective synthetic method for various glucosamine-based isocyanides and evaluation of their antifouling activity and toxicity against cypris larvae of the barnacle Amphibalanus amphitrite. Glucosamine isocyanides with an ether functionality at the anomeric position exhibited potent antifouling activity, with EC50 values below 1 mu g/mL, without detectable toxicity even at a high concentration of 10 mu g/mL. Two isocyanides had EC50 values of 0.23 and 0.25 mu g/mL, comparable to that of CuSO4, which is used as a fouling inhibitor (EC50 = 0.27 mu g/mL)
Total synthesis and biological activity of dolastatin 16
The total synthesis of dolastatin 16, a macrocyclic depsipeptide first isolated from the sea hare Dolabella auricularia as a potential antineoplastic metabolite by Pettit et al., was achieved in a convergent manner. Dolastatin 16 was reported by Tan to exhibit strong antifouling activity, and thus shows promise for inhibiting the attachment of marine benthic organisms such as Amphibalanus amphitrite to ships and submerged artificial structures. Therefore, dolastatin 16 is a potential compound for a new, environmentally friendly antifouling material to replace banned tributyltin-based antifouling paints. The synthesis of dolastatin 16 involved the use of prolinol to prevent formation of a diketopiperazine composed of L-proline and N-methyl-D-valine during peptide coupling. This strategy for the elongation of peptide chains allowed the efficient and scalable synthesis of one segment, which was subsequently coupled with a second segment and cyclized to form the macrocyclic framework of dolastatin 16. The synthetic dolastatin 16 exhibited potent antifouling activity similar to that of natural dolastatin 16 toward cypris larvae of Amphibalanus amphitrite