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.

There are provided, inter alia, derivatives of seriniquinone and methods useful for the treatment of cancer, and in particular treatment of melanoma and prostate cancer.

Seriniquinones, melanoma-specific anticancer agents

A novel tetracyclic polyketal from the marine red alga

Two new aromatic compounds, guaymasol (1) and epiguaymasol (2), have been isolated from cultures of a Bacillus species (isolate CNA-995) taken from a deep-sea sediment core. The structures, including relative stereochemistry, were assigned on the basis of spectral analyses of the natural products and their acetonide derivatives.

Guaymasol and Epiguaymasol: Aromatic Triols from a Deep-Sea Bacillus Isolate

Ammosamides A and B new cytotoxic alkaloids isolated from a marine Streptomyces sp

The intracellular localization and target of the napyradiomycin congeners CNQ525.510B and A80815C were explored using an immunoaffinity fluorescence (IAF) approach. Semi-synthetic methods were used to prepare probes from napyradiomycin CNQ525.510B and derivative A80815C. The results of confocal microscopy indicated that probes from both natural products localized predominantly within the endoplasmic reticulum (ER) of HCT-116 human colon carcinoma cells. Parallel immunoaffinity precipitation efforts using a monoclonal antibody designed against the IAF tag, resulted in the isolation of an Hsp90 family member. This protein was identified as human Grp94 (hGrp94), by its specific mass spectral signature. This observation was validated by Western blot analyses and by the result of an in vitro Grp94 binding assay. The fact that the napyradiomycins CNQ525.510B and A80815C bind to hGrp94, and their associated probes localize within the ER, suggest the use of these materials as molecular probes for monitoring ER-based chaperone function.

/pdf/napyradiomycins-cnq525-510b-and-a80915c-target-the-hsp90-2c2s5ciowf.pdf

William Fenical

Papers

Seriniquinones, melanoma-specific anticancer agents

A novel tetracyclic polyketal from the marine red alga

Guaymasol and Epiguaymasol: Aromatic Triols from a Deep-Sea Bacillus Isolate

Ammosamides A and B new cytotoxic alkaloids isolated from a marine Streptomyces sp

Napyradiomycins CNQ525.510B and A80915C target the Hsp90 paralogue Grp94.