Identification, Heterologous Expression, and Characterization of the Tolypodiol Biosynthetic Gene Cluster through an Integrated Approach.

Cyanobacteria are tremendous producers of biologically active natural products, including the potent anti-inflammatory compound tolypodiol. However, linking biosynthetic gene clusters with compound production in cyanobacteria has lagged behind that in other bacterial genera. Tolypodiol is a meroterpenoid originally isolated from the cyanobacterium HT-58-2.

Lipopolysaccharide from the Cyanobacterium sp. Induces Neutrophil Infiltration and Lung Inflammation.

Glucocorticoid-resistant asthma, which predominates with neutrophils instead of eosinophils, is an increasing health concern. One potential source for the induction of neutrophil-predominant asthma is aerosolized lipopolysaccharide (LPS). Cyanobacteria have recently caused significant tidal blooms, and aerosolized cyanobacterial LPS has been detected near the cyanobacterial overgrowth.

6-Deoxy- and 11-Hydroxytolypodiols: Meroterpenoids from the Cyanobacterium HT-58-2.

Chemical investigation of cyanobacterial strain HT-58-2, which most closely aligns with the genus , has led to the isolation of two compounds related to tolypodiol. The structures and absolute configuration of 6-deoxytolypodiol () and 11-hydroxytolypodiol () were elucidated by spectroscopic and spectrometric analysis. While tolypodiol previously showed anti-inflammatory activity in a mouse ear edema assay, only reduced thromboxane B and superoxide anion (O) generation from lipopolysaccharide-activated rat neonatal microglia to any appreciable degree.

Tolyporphins L-R: Unusual Tetrapyrroles from a sp. of Cyanobacterium.

Tolyporphins L-R (-) have been isolated from a mixed cyanobacterium-microbial culture. The structures of tolyporphins L and M have been revised to four constitutional isomers, isolated as two mixtures of dioxobacteriochlorins (/ and /). In contrast, tolyporphin P () is a fully oxidized tetrapyrrole, while tolyporphins Q and R ( and ) are oxochlorins.

-Selective Synthesis and Coordination Chemistry of Pyridine-Phosphaalkenes: Five Ligands Produce Four Distinct Types of Ru(II) Complexes.

Pyridine-phosphaalkene (PN) ligands were prepared in an -selective fashion using phospha-Wittig methodology. Treatment of these five ligands, varying only in their 6-substituent with RuCl(PPh), produced four distinct types of coordination complexes: pyridine-phosphaalkene-derived , cyclized , and six-coordinate and . Prolonged heating of in THF resulted in C-H activation of the Mes* group and cyclization to give featuring a bidentate pyridine-phospholane ligand bound to the metal center.

Biochemical and Functional Analysis of Cyanobacterium Geitlerinema sp. LPS on Human Monocytes.

Cyanobacterial blooms are an increasing source of environmental toxins that affect both human and animals. After ingestion of cyanobacteria, such as Geitlerinema sp., toxins and lipopolysaccharide (LPS) from this organism induce fever, gastrointestinal illness, and even death.

Quantitation of Tolyporphins, Diverse Tetrapyrrole Secondary Metabolites with Chlorophyll-Like Absorption, from a Filamentous Cyanobacterium-Microbial Community.

Introduction: Tolyporphins are unusual tetrapyrrole macrocycles produced by a non-axenic filamentous cyanobacterium (HT-58-2). Tolyporphins A-J, L, and M share a common dioxobacteriochlorin core, differ in peripheral substituents, and exhibit absorption spectra that overlap that of the dominant cyanobacterial pigment, chlorophyll a. Identification and accurate quantitation of the various tolyporphins in these chlorophyll-rich samples presents challenges.