Marine organisms provide several biologically active compounds that include alkaloids with high cytotoxic activity but only a few of them have so far reached clinical stage, due partly to their limited supply and complex structural features. In an attempt to develop novel anticancer compounds, w...

Topsentins and related bis-indole alkaloids may be efficiently synthesized through an addition/oxidation sequence leading to 2-(3-indolylcarbonyl)-imidazole derivatives followed by a Pd-catalyzed heteroarylation with the appropriate 3-stannylindoles.

Osteoporotic fracture is a significant public health problem, resulting in fractures in >50% of women and in almost one third of men age 65 and older. Most of the existing therapies act by slowing bone loss, through inhibiting the action of bone resorbing cells. However, more substantial reducti...

Yessotoxin (YTX) is a marine phycotoxin produced by dinoflagellates and accumulated in filter feeding shellfish. YTX content in shellfish is regulated by many food safety authorities to protect human health, although currently no human intoxication episodes have been unequivocally related to YTX...

A large dinoflagellate bloom in Walker Bay (South Africa) in January 2017 impacted 3 land-based abalone farms resulting in the death of several million animals. Satellite-derived images of Chl-a from the Ocean and Land Colour Imager (OLCI) on board the European Space Agency Sentinel-3 A showed b...

Series of gain-of-function missense mutations in PDR1 and PDR3 that encode transcription factors are known to increase the expression of ABC transporters that extrude various kinds of drugs out of a cell, leading to pleiotropic drug resistance (PDR). Previously, the PDR1-H176 (L309S) allele from...

The yeast transcription factors Pdr1 and Pdr3 control pleiotropic drug resistance (PDR) development, since they regulate expression of ATP-binding cassette (ABC) drug efflux pumps through binding to cis-acting sites known as PDREs (PDRresponsiveelements). In this report, we show by Northern blot...

Vegetation is critical to stabilize and remediate mine tailing sites, but plant growth is often poor due to toxicity from heavy metal(loid)s (HMs). A non-symbiotic endophytic fungus, Trichoderma sp. PDR1-7, isolated from Pb-contaminated mine tailing soil, exhibited both high tolerance to HMs and...

Overexpression and purification of membrane proteins has been a bottleneck for their functional and structural study for a long time. Both homologous and heterologous expression of membrane proteins with suitable tags for purification presents unique challenges for cloning and expression. Saccha...

The C-terminal 69 residues of the J-protein Zuo1 are sufficient to activate Pdr1, a transcription factor involved in both pleiotropic drug resistance and growth control. Little is understood about the pathway of activation by this primarily ribosome associated Hsp40 co-chaperone. Here, we report...

The cytotoxic compound, virgaureasaponin 1, was converted using several optimized enzyme-catalysed hydrolyses to the 28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-fucopyranoside (2), and the 28-O-α-l-rhamnopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl...

A new 3,28-bisdesmosidic triterpenoid glycoside was isolated from the mixture of deacylated saponins from the aerial parts of Solidago virgaurea. The structure of virgaureasaponin 3 was determined as 3-O-β-d-glucopyranosyl-(1→3)-β-d-glucopyranosylpolygalacic acid mainly by various 2D NMR tech...

Trifolitoxin production by Rhizobium leguminosarum bv. trifolii T24 was observed in three sterile soils. The three soils differed in texture and fertility. Two of these soils were silt loams while the third soil was a silty sand. One of the silt loams was amended with manure and composted. The a...

A rapid quantitative bioassay was developed which allows the measurement of trifolitoxin activity in 7 h. The previous assay required 2 days to observe trifolitoxin activity and was not quantitative. With this assay, we have defined a unit of trifolitoxin activity as that amount required to obse...

The present paper describes the formation of N-triflyl-7,8-dihydro-8(R),5′-O-cyclonucleosides during our efforts to introduce the triflate leaving group at the 5′-position of purine ribonucleoside derivatives. The chemical structure of these original cyclonucleosides, including the absolute co...

A series of C-6 alkyl, cycloalkyl, and aryl-9-(β-d-ribofuranosyl)purines were synthesized and their substrate activities with Escherichia coli purine nucleoside phosphorylase (E. coli PNP) were evaluated. (Ph3P)4Pd-mediated cross-coupling reactions of 6-chloro-9-(2,3,5-tri-O-acetyl-β-d-ribofur...

Studies of myocardial utilization of fatty acids and analogs has focused on coronary heart disease. This study addresses the topic of radioiodinated fatty acid utilization in hypertensive-cardiomyopathy. The new fatty acid analog 19-iodo-3,3-dimethyl-18 nonadecenoic acid (DMIVN) was studied by a...

The effect of methyl-branching at the 3(β-)-position on myocardial uptake and retention of fatty acids where radioiodide has been stabilized as a terminal trans-(E)-vinyl iodide has been evaluated in fasted rats. The syntheses of two new dimethyl-branched fatty acids, 17-iodo-3,3-dimethylheptad...

5′-O-Dimethoxytrityl deoxyribonucleoside 3′-O-phosphorbisdiethylamidites were prepared by the selective phosphitylation of 5′-O-dinethoxytrityl deoxyribonucleosides with tris(diethylamino)phosphine in the presence of amino and tetrazole as catalyst. The bisamidites activated by p-nitrophenylt...

Novel acid mono azo and mordent acid mono azo dyes were synthesized by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. The resulting dyes were characterized by spectral techniques like elemental analysis, IR, 1H-NMR and U...