Three dermacozines, dermacozines N–P (1–3), were isolated from the piezotolerant Actinomycete strain Dermacoccus abyssi MT 1.1T, which was isolated from a Mariana Trench sediment in 2006. Herein, we report the elucidation of their structures using a combination of 1D/2D NMR, LC-HRESI-MSn, UV–Visible, and IR spectroscopy. Further confirmation of the structures was achieved through the analysis of data from density functional theory (DFT)–UV–Visible spectral calculations and statistical analysis such as two tailed t-test, linear regression-, and multiple linear regression analysis applied to either solely experimental or to experimental and calculated 13C-NMR chemical shift data. Dermacozine N (1) bears a novel linear pentacyclic phenoxazine framework that has never been reported as a natural product. Dermacozine O (2) is a constitutional isomer of the known dermacozine F while dermacozine P (3) is 8-benzoyl-6-carbamoylphenazine-1-carboxylic acid. Dermacozine N (1) is unique among phenoxazines due to its near infrared (NIR) absorption maxima, which would make this compound an excellent candidate for research in biosensing chemistry, photodynamic therapy (PDT), opto-electronic applications, and metabolic mapping at the cellular level. Furthermore, dermacozine N (1) possesses weak cytotoxic activity against melanoma (A2058) and hepatocellular carcinoma cells (HepG2) with IC50 values of 51 and 38 μM, respectively.
Bibliographical noteFunding: Dawrin Pech-Puch received his postdoctoral fellowship from the National Council of Science and Technology (CONACYT) of Mexico.
Acknowledgments: The authors wish to express their thanks to Michael Goodfellow, School of Nat- ural and Environmental Sciences, Newcastle University for providing the pure colony of Dermacoccus abyssi MT 1.1T, to Wasu Pathom-Aree (Chiang Mai University, Thailand), who isolated the strain fur- thermore to the Kaiko operation team and the crew of M.S. Yokosuka, JAMSTEC, Yokosuka, Japan, for the sediment collection. The authors thank and acknowledge the significant contribution of John W. Still—SEM Specialist, ACEMAC Facility, The University of Aberdeen; Lucinda Wight—Microscope and Histology Specialist, School of Medicine, Medical Sciences and Nutrition, The University of Aberdeen for preparing the strain Dermacoccus abyssi MT 1.1T for EM imaging; Russel Gray for NMR measurements—The University of Aberdeen, Department of Chemistry, Marine Biodiscovery Centre, NMR Laboratory; Bella Juraj for NMR measurements—The University of Edinburgh, Joseph Black Building, School of Chemistry, NMR Laboratory. Marcel Jaspars and Bertalan Juhasz acknowledge the help of the University of Edinburgh through the EPSR Grant: EP/R030065/1 for the 800 MHz NMR measurements with the 5 mm TCI He Cryoprobe of compounds 1 and 2. Carlos Jimenéz and Dawrin Pech-Puch acknowledge the help of CESGA for the computational support. Bertalan Juhasz wishes to express his sincere gratitude to his supervisor, Marcel Jaspars, for his invaluable trust and support.
- deep sea natural products
- Mariana Trench
- Dermacoccus abyssi MT 1.1T
- 13C-NMR chemical shift linear and multiple regression
- (DFT)-UV-Vis spectral calculation
- absorption maxima in the near infrared region