| patellamide e: a new cyclic peptide from the ascidian lissoclinum patella. | a new cyclic peptide, patellamide e [1], was isolated from the ascidian lissoclinum patella collected at pulau salu, singapore. its structure was determined by nmr spectroscopy, and its absolute configuration by acid hydrolysis and analysis of the derivatized constituent amino acids by hplc. patellamide e was mildly cytotoxic against human colon tumor cells in vitro. | 1992 | 1593285 |
| multiple evolutionary origins of prochlorophytes within the cyanobacterial radiation. | the taxonomic group prochlorales (lewin 1977) burger-wiersma, stal and mur 1989 was established to accommodate a set of prokaryotic oxygenic phototrophs which, like plant, green algal and euglenoid chloroplasts, contain chlorophyll b instead of phycobiliproteins. prochlorophytes were originally proposed (with concomitant scepticism) to be a monophyletic group sharing a common ancestry with these 'green' chloroplasts. results from molecular sequence phylogenies, however, have suggested that proch ... | 1992 | 1731225 |
| lissoclinolide, the first non-nitrogenous metabolite from a lissoclinum tunicate. | the isolation and characterization of a new metabolite from the tunicate lissoclinum patella is described. the structure of lissoclinolide [1] was solved using spectral and chemical methods, and it is shown to be the first non-nitrogenous, non-sulfur-containing compound to be isolated from the genus lissoclinum. | 1990 | 2095371 |
| structure-activity relationships of the lissoclinamides: cytotoxic cyclic peptides from the ascidian lissoclinum patella. | two new lissoclinamides (lissoclinamides 7 and 8) have been isolated from the aplousobranch ascidian lissoclinum patella. these lissoclinamides are cyclic heptapeptides with the same structural features as lissoclinamides 4 and 5 reported earlier, containing an oxazoline ring, one proline, one valine, two phenylalanine residues, and thiazole and/or thiazoline rings. all four peptides have the same sequence of amino acids around the ring and differ from one another only in their stereochemistry o ... | 1990 | 2342056 |
| new cyclic peptides with cytotoxic activity from the ascidian lissoclinum patella. | the isolation and structures of a new patellamide (patellamide d) and two new lissoclinamides (lissoclinamides 4 and 5) from the aplousobranch ascidian lissoclinum patella are described. structures were determined largely by using two-dimensional nmr techniques and mass spectrometry. these peptides and other members of the patellamide and lissoclinamide families that have been reported previously are found within the obligate algal symbiont of the genus prochloron. the cytotoxicities of the comp ... | 1989 | 2724305 |
| novel cytotoxic compounds from the ascidian lissoclinum bistratum. | the isolation and structures of two new cyclic hexapeptides and two new macrocyclic ethers from the aplousobranch ascidian lissoclinum bistratum are described. their structures were determined by two-dimensional nmr techniques. the hexapeptides, named bistratamide a and bistratamide b, differ only by the presence or absence of one double bond. they were tested for cytotoxicity toward human fibroblast and tumor cell lines and displayed similar toxicities to the octapeptides called patellamides fr ... | 1989 | 2724306 |
| identification of | [8-vinyl]-protochlorophyllide a1 was isolated from a prochloron sp. associated with the host ascidian, lissoclinum patella. to obtain sufficient amounts for identification of the purified pigment, suitable extraction procedures and hplc systems were developed. the structure was finally elucidated by uv-vis and fluorescence spectroscopy, mass spectrometry and nmr (rotating-frame overhauser enhancement spectroscopy). [8-vinyl]-protochlorophyllide a was originally detected only as an intermediate i ... | 1999 | 10082792 |
| localization studies of ioactive cyclic peptides in the ascidian lissoclinum patella. | a palauan specimen of the ascidian lissoclinum patella contained the cyclic peptides patellamides a-c. in contrast to previous reports concerning the location of cyclic peptides in l. patella and l. bistratum, it has been demonstrated that these cyclic peptides were not located in the symbiotic cyanobacterium prochloron sp. but were instead distributed throughout the ascidian tunic. the relevance of these results with respect to the biosynthetic origins of the patellamides is discussed. | 2002 | 12027743 |
| ultraviolet-light-absorbing tunic cells in didemnid ascidians hosting a symbiotic photo-oxygenic prokaryote, prochloron. | coral reef invertebrates that host phototrophic symbionts are thought to protect themselves and their symbionts with mycosporine-like amino acids (maas)-uv-absorbing substances that act as sunscreens (dunlap, w. c., and j. m. shick, 1998. j. phycol. 34: 418-430). however, the histological distribution of maas in the host tissues has not yet been visualized. we have localized the uv-absorbing substances in the tissues of two colonial didemnid ascidians-lissoclinum patella and diplosoma sp.-that c ... | 2003 | 12700141 |
| photosynthesis of prochloron as affected by environmental factors. | the effects of light intensity, ph, temperature, and uv irradiation on the photosynthetic rate of prochloron isolated from the ascidian host lissoclinum patella, collected from palau, were examined. photosynthesis increased with light intensity with saturation at 500 micromol/m(2) per second. it was maximum at ph 8 to 9 but almost completely suppressed below ph 7. the optimum temperature was 35 degrees to 40 degrees c, but the photosynthesis was absent at < or =20 degrees c and at 45 degrees c. ... | 2001 | 14961393 |
| a profile of the in vitro antitumor activity of lissoclinolide. | lissoclinolide is a small non-nitrogenous lactone isolated from the marine ascidian lissoclinum patella. previous studies of lissoclinolide (isolated from a fungus and an actinomycete) have identified varying activity against both gram-negative and gram-positive bacteria. in this study, lissoclinolide was able to inhibit cell growth in various mammalian tumor lines at an average ic(50) of 395 nm (determined by mtt conversion after 48-h treatment). treatment of hct 116 human colon tumor cells wit ... | 2004 | 14962505 |
| patellamide a and c biosynthesis by a microcin-like pathway in prochloron didemni, the cyanobacterial symbiont of lissoclinum patella. | prochloron spp. are obligate cyanobacterial symbionts of many didemnid family ascidians. it has been proposed that the cyclic peptides of the patellamide class found in didemnid extracts are synthesized by prochloron spp., but studies in which host and symbiont cells are separated and chemically analyzed to identify the biosynthetic source have yielded inconclusive results. as part of the prochloron didemni sequencing project, we identified patellamide biosynthetic genes and confirmed their func ... | 2005 | 15883371 |
| photoadaptation and protection against active forms of oxygen in the symbiotic procaryote prochloron sp. and its ascidian host. | superoxide dismutase, ascorbate peroxidase, and catalase activities were studied in the symbiotic photosynthetic procaryote prochloron sp. and its ascidian host lissoclinum patella. the protein-specific activities of these antioxidant enzymes in the prochloron sp. and l. patella collected at different depths from the great barrier reef, australia, were directly proportional to irradiance, whereas the pigment concentrations in the prochloron sp. were inversely proportional to irradiance. the pres ... | 1990 | 16348202 |
| identifying bacterial genes and endosymbiont dna with glimmer. | the glimmer gene-finding software has been successfully used for finding genes in bacteria, archaea and viruses representing hundreds of species. we describe several major changes to the glimmer system, including improved methods for identifying both coding regions and start codons. we also describe a new module of glimmer that can distinguish host and endosymbiont dna. this module was developed in response to the discovery that eukaryotic genome sequencing projects sometimes inadvertently captu ... | 2007 | 17237039 |
| azole-based cyclic peptides from the sea squirt lissoclinum patella: old scaffolds, new avenues. | | 2010 | 20632432 |
| Complex microbiome underlying secondary and primary metabolism in the tunicate-Prochloron symbiosis. | The relationship between tunicates and the uncultivated cyanobacterium Prochloron didemni has long provided a model symbiosis. P. didemni is required for survival of animals such as Lissoclinum patella and also makes secondary metabolites of pharmaceutical interest. Here, we present the metagenomes, chemistry, and microbiomes of four related L. patella tunicate samples from a wide geographical range of the tropical Pacific. The remarkably similar P. didemni genomes are the most complex so far as ... | 2011 | 22123943 |
| Microbial diversity of biofilm communities in microniches associated with the didemnid ascidian Lissoclinum patella. | We assessed the microbial diversity and microenvironmental niche characteristics in the didemnid ascidian Lissoclinum patella using 16S rRNA gene sequencing, microsensor and imaging techniques. L. patella harbors three distinct microbial communities spatially separated by few millimeters of tunic tissue: (i) a biofilm on its upper surface exposed to high irradiance and O(2) levels, (ii) a cloacal cavity dominated by the prochlorophyte Prochloron spp. characterized by strong depletion of visible ... | 2011 | 22134643 |
| the structure of ulithiacyclamide b. antitumor evaluation of cyclic peptides and macrolides from lissoclinum patella. | the major cytotoxic metabolites of lissoclinum patella from pohnpei have been isolated and identified. most of the cytotoxicity is attributed to a new cyclic peptide, ulithiacyclamide b [4], which is closely related to ulithiacyclamide [1]. the proposed structure of 4 is based on spectroscopic analysis and chemical degradation. compound 4 exhibits an ic50 of 17 ng/ml against the kb cell line but does not show selective cytotoxicity against solid tumor cells in the corbett assay. | 1999 | 2809606 |
| microenvironmental ecology of the chlorophyll b-containing symbiotic cyanobacterium prochloron in the didemnid ascidian lissoclinum patella. | the discovery of the cyanobacterium prochloron was the first finding of a bacterial oxyphototroph with chlorophyll (chl) b, in addition to chl a. it was first described as prochloron didemni but a number of clades have since been described. prochloron is a conspicuously large (7-25 μm) unicellular cyanobacterium living in a symbiotic relationship, primarily with (sub-) tropical didemnid ascidians; it has resisted numerous cultivation attempts and appears truly obligatory symbiotic. recently, a p ... | 2012 | 23226144 |
| bacterial endosymbiosis in a chordate host: long-term co-evolution and conservation of secondary metabolism. | intracellular symbiosis is known to be widespread in insects, but there are few described examples in other types of host. these symbionts carry out useful activities such as synthesizing nutrients and conferring resistance against adverse events such as parasitism. such symbionts persist through host speciation events, being passed down through vertical transmission. due to various evolutionary forces, symbionts go through a process of genome reduction, eventually resulting in tiny genomes wher ... | 2013 | 24324632 |