Alternative Biosynthetic Starter Units Enhance the Structural Diversity of Cyanobacterial Lipopeptides.

Puwainaphycins (PUWs) and minutissamides (MINs) are structurally analogous cyclic lipopeptides possessing cytotoxic activity. Both types of compound exhibit high structural variability, particularly in the fatty acid (FA) moiety. Although a biosynthetic gene cluster responsible for synthesis of several PUW variants has been proposed in a cyanobacterial strain, the genetic background for MINs remains unexplored.

Impaired secondary oxidant deactivation capacity and enhanced oxidative stress in serum from alveld affected lambs.

Alveld is a hepatogenous photosensitivity disorder in lambs. The aim of the study was to investigate if alveld affected lambs had a reduced capacity to handle oxidative stress induced from either endogenous and/or exogenous photosensitizers. Serum samples from alveld lambs (n=33) were compared to serum samples from control lambs (n=31) and exposed to a controlled amount of singlet oxygen ((1)O2).

Identification of singlet oxygen photosensitizes in lambs drinking water in an alveld risk area in West Norway.

Alveld is a hepatogenous photosensitivity disorder in lambs. Although alveld has been known in Norway for more than 100years, there are still questions related to the cause of the disease. Phytoporphyrin has long been incriminated as the photosensitizer in hepatogenous photosensitivity diseases but previous findings suggest that the photosensitizing mechanism in alveld is more complex, possibly involving other co-factors.

The apoptosis-inducing activity towards leukemia and lymphoma cells in a cyanobacterial culture collection is not associated with mouse bioassay toxicity.

Cyanobacteria (83 strains and seven natural populations) were screened for content of apoptosis (cell death)-inducing activity towards neoplastic cells of the immune (jurkat acute T-cell lymphoma) and hematopoetic (acute myelogenic leukemia) lineage. Apoptogenic activity was frequent, even in strains cultured for decades, and was unrelated to whether the cyanobacteria had been collected from polar, temperate, or tropic environments. The activity was more abundant in the genera Anabaena and Microcystis compared to Nostoc, Phormidium, Planktothrix, and Pseudanabaena.

Detection of singlet oxygen in blood serum samples of clinically healthy lambs and lambs suffering from alveld disease.

Alveld is a disease in lambs of domestic sheep (Ovis aries L.), characterized by a combination of photosensitivity and liver damage. Generation of singlet oxygen play a major role in phototoxicity reactions.