Limits...
Mass spectrometry imaging reveals new biological roles for choline esters and Tyrian purple precursors in muricid molluscs.

Rudd D, Ronci M, Johnston MR, Guinan T, Voelcker NH, Benkendorff K - Sci Rep (2015)

Bottom Line: But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation.Murexine was found to tranquilise the larvae and may relax the reproductive tract.This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Flinders University, Bedford Park, SA 5042, Australia.

ABSTRACT
Despite significant advances in chemical ecology, the biodistribution, temporal changes and ecological function of most marine secondary metabolites remain unknown. One such example is the association between choline esters and Tyrian purple precursors in muricid molluscs. Mass spectrometry imaging (MSI) on nano-structured surfaces has emerged as a sophisticated platform for spatial analysis of low molecular mass metabolites in heterogeneous tissues, ideal for low abundant secondary metabolites. Here we applied desorption-ionisation on porous silicon (DIOS) to examine in situ changes in biodistribution over the reproductive cycle. DIOS-MSI showed muscle-relaxing choline ester murexine to co-localise with tyrindoxyl sulfate in the biosynthetic hypobranchial glands. But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation. Murexine was found to tranquilise the larvae and may relax the reproductive tract. This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology.

No MeSH data available.


Related in: MedlinePlus

The enzymatic, oxidative and photolytic reaction of bioactive compounds found in D. orbita hypobranchial glands (Muricidae, Mollusca) with corresponding solubility indicator.aLog P was calculated using the chemoinformatics software Molinspiration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4555103&req=5

f1: The enzymatic, oxidative and photolytic reaction of bioactive compounds found in D. orbita hypobranchial glands (Muricidae, Mollusca) with corresponding solubility indicator.aLog P was calculated using the chemoinformatics software Molinspiration.

Mentions: Muricidae molluscs have been of significant interest as biological and chemical resources since antiquity2627. They are a source of biologically active brominated indoles (Fig. 1) that are precursors to the historically significant dye Tyrian purple28. Tyrian purple (6,6′-dibromoindigo) was the first marine natural product to be structurally elucidated (Friedlander 1909)29 and is still commonly used as a tool for teaching organic chemistry30. Nevertheless, the biological function of Tyrian purple remains unknown and is suggested to simply be an artefact31 formed from the degradation of indoxyl sulfate precursors, which are stored as salts of choline ester derivatives (e.g. murexine, Fig. 1) in the hypobranchial gland of these molluscs32. Tyrian purple production is initiated by reaction of the indoxyl sulfate precursors with an aryl sulfatase enzyme (Fig. 1), which is also produced and stored in the mollusc33, thus suggesting a regulated ecological function for the precursors. Muricidae choline esters show marked neuromuscular blocking activity34 and have been implicated in the paralysis of prey by these predatory molluscs34, whereas the brominated indole intermediates have antibacterial activity and have been implicated in the defense of the egg capsules35. The brominated indoles have also been found in extracts of the reproductive organs36, suggesting a maternal source for the egg capsules. However, it is unclear if the choline esters are also transferred into the egg capsules or why the molluscs constitutively produce and store these two distinct classes of compounds as an indoxyl sulfate-choline ester salt in the hypobranchial glands for controlled release on reaction with aryl sulfatase.


Mass spectrometry imaging reveals new biological roles for choline esters and Tyrian purple precursors in muricid molluscs.

Rudd D, Ronci M, Johnston MR, Guinan T, Voelcker NH, Benkendorff K - Sci Rep (2015)

The enzymatic, oxidative and photolytic reaction of bioactive compounds found in D. orbita hypobranchial glands (Muricidae, Mollusca) with corresponding solubility indicator.aLog P was calculated using the chemoinformatics software Molinspiration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555103&req=5

f1: The enzymatic, oxidative and photolytic reaction of bioactive compounds found in D. orbita hypobranchial glands (Muricidae, Mollusca) with corresponding solubility indicator.aLog P was calculated using the chemoinformatics software Molinspiration.
Mentions: Muricidae molluscs have been of significant interest as biological and chemical resources since antiquity2627. They are a source of biologically active brominated indoles (Fig. 1) that are precursors to the historically significant dye Tyrian purple28. Tyrian purple (6,6′-dibromoindigo) was the first marine natural product to be structurally elucidated (Friedlander 1909)29 and is still commonly used as a tool for teaching organic chemistry30. Nevertheless, the biological function of Tyrian purple remains unknown and is suggested to simply be an artefact31 formed from the degradation of indoxyl sulfate precursors, which are stored as salts of choline ester derivatives (e.g. murexine, Fig. 1) in the hypobranchial gland of these molluscs32. Tyrian purple production is initiated by reaction of the indoxyl sulfate precursors with an aryl sulfatase enzyme (Fig. 1), which is also produced and stored in the mollusc33, thus suggesting a regulated ecological function for the precursors. Muricidae choline esters show marked neuromuscular blocking activity34 and have been implicated in the paralysis of prey by these predatory molluscs34, whereas the brominated indole intermediates have antibacterial activity and have been implicated in the defense of the egg capsules35. The brominated indoles have also been found in extracts of the reproductive organs36, suggesting a maternal source for the egg capsules. However, it is unclear if the choline esters are also transferred into the egg capsules or why the molluscs constitutively produce and store these two distinct classes of compounds as an indoxyl sulfate-choline ester salt in the hypobranchial glands for controlled release on reaction with aryl sulfatase.

Bottom Line: But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation.Murexine was found to tranquilise the larvae and may relax the reproductive tract.This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Flinders University, Bedford Park, SA 5042, Australia.

ABSTRACT
Despite significant advances in chemical ecology, the biodistribution, temporal changes and ecological function of most marine secondary metabolites remain unknown. One such example is the association between choline esters and Tyrian purple precursors in muricid molluscs. Mass spectrometry imaging (MSI) on nano-structured surfaces has emerged as a sophisticated platform for spatial analysis of low molecular mass metabolites in heterogeneous tissues, ideal for low abundant secondary metabolites. Here we applied desorption-ionisation on porous silicon (DIOS) to examine in situ changes in biodistribution over the reproductive cycle. DIOS-MSI showed muscle-relaxing choline ester murexine to co-localise with tyrindoxyl sulfate in the biosynthetic hypobranchial glands. But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation. Murexine was found to tranquilise the larvae and may relax the reproductive tract. This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology.

No MeSH data available.


Related in: MedlinePlus