Robert A. Hill

Production of macrosphelide A by the mycoparasite Coniothyrium minitans

Coniothyrium minitans, a mycoparasite of sclerotia of Sclerotinia sclerotiorum and Sclerotium cepivorum, produced four closely related metabolites inhibitory to fungal growth. The major metabolite, identified as macrosphelide A, had IG(50) values (the concentration of metabolite to inhibit growth by 50%) of 46.6 and 2.9 microgram ml(-1) against S. sclerotiorum and S. cepivorum, respectively. This is the first report of both antifungal activity due to macrosphelide A as well as isolation of macrosphelide A from C. minitans.

Naturally Occurring Isocoumarins

Isocoumarins have been isolated from a wide variety of microbial, plant and insect sources and have been shown to possess an impressive array of biological activities. Since the review by Barry in 1963 (24), the number of known naturally occurring isocoumarins has increased dramatically. This increase is largely due to improvements in isolation procedures and structural analysis. Previous reviews have concentrated on fungal isocoumarins (293, 294) and mycotoxic isocoumarins (301). This review lists over 160 naturally occurring isocoumarins. Leading references on isolation, structure elucidation, biosynthesis and synthesis are given in the accompanying Tables.

Production of catechols and muconic acids from various aromatics by the styrene-degraderRhodococcus rhodochrous NCIMB 13259

SummaryIntact cells ofRhodococcus rhodochrous NCIMB 13259 which had been grown in the presence of styrene were used to produce metabolic intermediates from other aromatic substrates in the presence of 3-fluorocatechol as an inhibitor of catechol oxygenase. Toluene and ethylbenzene gave 3-methylcatechol and 3-ethylcatechol respectively. The enol form of 3-acetylcatechol was produced from acetophenone and 1-phenylethanol. Benzoic acid was produced from cinnamic acid. This organism cannot metabolise muconic acids, and methylmuconic acid and ethylmuconic acid accumulated under appropriate conditions. 2-Fluoromuconic acid was also produced from the added 3-fluorocatechol. This organism provides a convenient tool for producing catechols and muconic acids from a variety of substrates without need for gentic manipulation.

Antimicrobial activity of Coniothyrium minitans and its macrolide antibiotic macrosphelide A

Aims:u2002 Assessment of antimicrobial activity of the mycoparasite Coniothyrium minitans and its macrolide antibiotic macrosphelide A.

7 Marine natural products

This review covers the literature on marine natural products published in 2003. Methods of isolation and structure elucidation continue to improve with the result that the number of new marine natural products increases each year. This review covers a small part of the literature to highlight some of the diverse structural types and associated biological activities. Marine sponges are the source of the largest number of new natural products this year, however the large range of metabolites available from cultured marine microorganisms is of growing interest. This review is organised similarly to the last one with the natural products grouped loosely under their biogenetic origins of polyketides, terpenoids and alkaloids and peptides.

Some environmental factors affect growth and antibiotic production by the mycoparasite Coniothyrium minitans

Abstract The effects of temperature and pH on growth and antibiotic production by three isolates of Coniothyrium minitans (Conio, Contans and IVT1), known to produce the macrolide antibiotic macrosphelide A, were examined in modified Czapek Dox broth (MCD). Antibiotic production was determined by incorporating heated (60°C for 5 min) C. minitans spent culture filtrates of MCD (10%, v/v) into potato dextrose broth and assessing the ability of the filtrates to inhibit growth of S. sclerotiorum. All isolates grew over the temperature range of 10–30°C, with the optimum at approximately 15–20°C. Antibiotics were produced by all isolates at 10–30°C. Culture filtrates of MCD from all isolates incorporated into PDB inhibited growth of S. sclerotiorum by >50%, whereas there was a reduction in inhibition at 30°C for Conio and IVT1 but not Contans. All three isolates grew over the pH range of 3–7, with greater biomass production in buffered pH 3–5 than the unbuffered control (pH 4.8) media. Antibiotics were produced by all isolates at pH 3–5. Culture filtrates of MCD from all three isolates grown at pH 3–5 inhibited growth of S. sclerotiorum, with the greatest effect on inhibition observed at pH 3. There were no differences in growth inhibition between isolates at pH 3 and 4, but culture filtrates from Conio grown at pH 5 inhibited S. sclerotiorum more than those of IVT1 grown at the same pH. The significance of these results for biocontrol and optimizing antibiotic production by C. minitans is discussed.

5 Marine natural products

This review covers the literature on marine natural products published in 2002. As in previous years there has been enormous interest in the structure elucidation, synthesis, activity and ecology of marine natural products. Marine sources produce compounds of new structural types with an intriguing array of biological activities. Sponges are the commonest organisms to be studied, however, algae, bacteria and fungi have been far from neglected. The bioactivity-guided extraction and purification of crude extracts has produced highly potent compounds. Marine species have been interacting chemically for billions of years and it is no wonder that there have evolved natural products with such high activity. Some are highly toxic whereas others have very selective activities and have the potential to be used therapeutically.

Inhibition of phospholipid signalling and proliferation of Swiss 3T3 cells by the wortmannin analogue demethoxyviridin

Growth factors and certain oncogenes activate a range of phospholipid-mediated signal transduction pathways resulting in cell proliferation. Demethoxyviridin (DMV), a structural analogue of wortmannin and recently reported as a potent inhibitor of phosphoinositide-3-kinase, inhibited bombesin plus insulin-stimulated increase in cell number in Swiss 3T3 cells, a model of cell proliferation. The drug produced cytostatic effects at concentrations below 1 microM and cytotoxic effects at 10 microM. In intact Swiss 3T3 cells DMV inhibited insulin-stimulated PI 3- and 4-kinases and bombesin-stimulated phospholipases C, D and A2 in the nanomolar range. DMV also inhibited bombesin-stimulated tyrosine phosphorylation of a range of proteins at nM concentrations. This study shows that DMV inhibited multiple stimulated signalling pathways which lead to increased Swiss 3T3 cell proliferation. A stable analogue of DMV may have chemotherapeutic potential.

Gospel, poverty and Catholic schools

Abstract Catholic schools in Scotland have a long history of serving the needs of the poor and are called to share in the contemporary Catholic preferential option for the poor and the international and national initiatives that include addressing the problem of child poverty through school education. The Catholic preferential option for the poor and the international/national discourse on the eradication of poverty in relation to Catholic schools are, however, underpinned by some fundamental concepts and discussions that require deeper exploration. First, the gospel conceptualisation of poverty, heavily rooted in the Jewish understanding of the poor and the role of the poor, requires elucidation as it is often underdeveloped. Second, the contemporary discussion about the nature and scope of poverty in the Western world and, in particular, how this impacts on children and their education, also requires attention as this will have significant implications for Catholic schools. This article aims to provide an initial exploration of these fundamental concepts and discussions and attempts to identify possible correlation and links between the gospel concept of poverty and the contemporary discussion on Western poverty. The article will explore the Lukan concept of the poor as ‘the excluded’ and the contemporary potential for exclusion within school contexts experienced by children from poor backgrounds within Scotland, focussing on Catholic schools. This will be followed by a reflective response to the issues raised in this article by Mr Michael McGrath, the director of the Scottish Catholic Education Service. The article will conclude by suggesting that this correlation and these links are important for Catholic schools in Scotland if they are to be consistent in their preferential option for the poor. This may also have implications for the wider international network of Catholic schools.

Correction: Hot off the press.

Correction for Hot off the press by Robert A. Hill et al., Nat. Prod. Rep., 2016, DOI: 10.1039/c6np90039a.