Dermacoccus abyssi sp. nov., strains MT1.1 and MT1.2 are actinomycetes isolated from Mariana Trench sediment at a depth of 10 898 m. Fermentation using ISP2 and 410 media, respectively, lead to production of seven new oxidized and reduced phenazine-type pigments, dermacozines A–G (1–7), together with the known phenazine-1-carboxylic acid (8) and phenazine-1,6-dicarboxylic acid (9). Extensive use was made of 1D and 2D-NMR data, and high resolution MS to determine the structures of the compounds. To confirm the structure of the most complex pentacyclic analogue (5) we made use of electronic structure calculations to compare experimental and theoretical UV-Vis spectra, which confirmed a novel structural class of phenazine derivatives, the dermacozines. The absolute stereochemistry of dermacozine D (4) was determined as S by a combination of CD spectroscopy and electronic structure calculations. Dermacozines F (6) and G (7) exhibited moderate cytotoxic activity against leukaemia cell line K562 with IC50 values of 9 and 7 mM, respectively, while the highest radical scavenger activity was observed for dermacozine C (3) with an IC50 value of 8.4 mM.

We report here on the discovery and structure determination of three new diastereomeric pairs of cyclic ether acetogenins, laurefurenynes A–F, isolated from the aqueous extract of the alga Laurencia sp. collected in the Philippines. Extensive use was made of NMR spectroscopic data and high resolution MS to determine the structures of the pure compounds. The most stable and the lowest energy conformation was determined using molecular modelling, and their cytotoxic activity was tested against different tumour cells, a significant indication that laurefurenyne C and F are moderately cytotoxic, but non selective whilst the others are inactive.

Cyclodextrins (CyDs) were employed as protective stabilizers for the preparation of surfactant-free nanocrystals of indomethacin (IMC) by using the emulsion solvent diffusion method. The effect of changing the type and concentration of CyDs on the formation of IMC nanocrystals was investigated. Dispersions were freeze-dried to characterize the size, shape, nanoparticle yield, crystallinity, and dissolution behavior of the obtained particles. Submicron-sized particles of IMC with average diameters in the range of 300-500 nm were obtained by incorporating α-, β-, or γ-CyD in the outer phase of the primary emulsions. Quantitative determination demonstrated that more than 80% of IMC was recovered as fine particles smaller than 0.8 µm. The powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses of the freeze-dried samples confirmed the polymorphic change of IMC to the meta-stable form. A significant enhancement in the dissolution rate of IMC nanocrystals was observed when compared to the commercial powder.

The concept of mucoadhesion for the design of non-invasive drug delivery systems gained increasing attention in recent years. Within the current review, various mucoadhesive polymers, including poly(acrylates), chitosan, thiolated polymers and others, as well as their use in mucosal drug delivery are discussed. An emphasis has been put on the development of mucoadhesive formulations, and in particular on recently developed micro- and nanoparticulate systems. Moreover, the applications of the mucadhesive carrier systems for different administration routes such as the oral, nasal, pulmonary and ocular route are discussed.