The results of a single-crystal structure determination when in CIF format can now be validated routinely by automatic procedures. In this way, many errors in published papers can be avoided. The validation software generates a set of ALERTS detailing issues to be addressed by the experimenter, author, referee and publication journal. Validation was pioneered by the IUCr journal Acta Crystallographica Section C and is currently standard procedure for structures submitted for publication in all IUCr journals. The implementation of validation procedures by other journals is in progress. This paper describes the concepts of validation and the classes of checks that are carried out by the program PLATON as part of the IUCr checkCIF facility. PLATON validation can be run at any stage of the structure refinement, independent of the structure determination package used, and is recommended for use as a routine tool during or at least at the completion of every structure determination. Two examples are discussed where proper validation procedures could have avoided the publication of incorrect structures that had serious consequences for the chemistry involved.

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Single-crystal structure validation with the program PLATON

Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes.

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Physiological and ecological constraints play key roles in the evolution of plant growth patterns, especially in relation to defenses against herbivores. Phenotypic and life history theories are unified within the growth-differentiation balance (GDB) framework, forming an integrated system of theories explaining and predicting patterns of plant defense and competitive interactions in ecological and evolutionary time. Plant activity at the cellular level can be classified as growth (cell division and enlargement) of differentiation (chemical and morphological changes leading to cell maturation and specialization). The GDB hypothesis of plant defense is premised upon a physiological trade-off between growth and differentiation processes. The trade-off between growth and defense exists because secondary metabolism and structural reinforcement are physiologically constrained in dividing and enlarging cells, and because they divert resources from the production of new leaf area. Hence the dilemma of plants: Th...

https://www.jstor.org/stable/pdfplus/2830650.pdf

The dilemma of plants: To grow or defend.

Advances in flavonoid research since 1992.

Simple antibiotics from the red seaweed Dasya pedicellata var. Stanfordiana

The chemistry of marine bacteria

Neomarinone (1), a novel metabolite possessing a new sesquiterpene- and polyketide-derived carbon skeleton, and several derivatives, 3–5, of the marinone class of naphthoquinone antibiotics, were isolated from the fermentation broth of a taxonomically-novel marine actinomycete (strain #CNH-099). The structures of the new compounds were determined by comprehensive NMR and mass spectral analyses. Neomarinone (1) and several of the marinone derivatives were shown to be moderately cytotoxic toward human cancer cells in in vitro testing.

Neomarinone, and New Cytotoxic Marinone Derivatives, Produced by a Marine Filamentous Bacterium (Actinomycetales).

10-bromo-α-chamigrene

Marine micro-organisms represent an under explored resource for the discovery of novel antiviral agents. Here, we describe a series of peptides designated halovirs A-E (1-5) that are produced during the saline fermentation of a marine-derived fungus of the genus Scytalidium. These lipophilic, linear peptides are potent in vitro inhibitors of the herpes simplex viruses 1 and 2. Evidence is presented that the halovirs directly inactivate herpes viruses, a mechanism of action that could be applicable in the prevention of HSV transmission. The total structures of these new compounds were established by a combination of spectral and chemical techniques. Salient structural features of the halovir hexapeptides include a nitrogen terminus acylated by myristic (C14) or lauric (C12) acid, an unusual Aib-Hyp dipeptide segment, and a carboxyl terminus reduced to a primary alcohol. A qualitative analysis of the secondary structures of these molecules using variable temperature NMR experiments and NOE analyses is also reported.

William Fenical

Papers

Simple antibiotics from the red seaweed Dasya pedicellata var. Stanfordiana

The chemistry of marine bacteria

Neomarinone, and New Cytotoxic Marinone Derivatives, Produced by a Marine Filamentous Bacterium (Actinomycetales).

10-bromo-α-chamigrene

Halovirs A‐E, New Antiviral Agents from a Marine‐Derived Fungus of the Genus Scytalidium.