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.

/pdf/single-crystal-structure-validation-with-the-program-platon-2pdiuo25f2.pdf

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.

The Junceellolides: New Antiinflammatory Diterpenoids of the Briarane Class from the Chinese Gorgonian Junceella fragilis.

Kozmin et al. contend that observations previously reported regarding the antimicrobial and antitumor activities of 6-N-hydroxy aminopurine (6-HAP) were incorrect. Their conclusions rely on poorly characterized reagents and focus strictly on in vitro techniques without validation in relevant mammalian model systems. We are pleased to be able to illuminate the weaknesses in their technical comment. The totality of current results continues to support our original conclusion that a strain of the common human commensal skin bacterium, Staphylococcus epidermidis, produces 6-HAP that can inhibit tumor growth.

/pdf/response-to-comment-on-a-commensal-strain-of-staphylococcus-3eg2ks9dne.pdf

Response to Comment on “A commensal strain of Staphylococcus epidermidis protects against skin neoplasia” by Nakatsuji et al.

A novel family of cyclic polyene natural products isolated from marine actinomycete strain CNQ 140 is provided. This novel strain of actinomycetes was obtained from a previously unstudied population of marine actinomycetes that reside in sediments off La Jolla, California. Compounds derived from strain CNQ 140 have been characterized as having a cyclic polyene-polyol structure; a molecular weight from about 996 to about 1010 in the core ring structure; and at least 58 carbons and at least 14 oxygens. The invention compounds have antitumor and/or anti-microbial activity.

Novel polyol macrolide antitumor-antibiotics from the novel marine actinomycete strain cnq140

Three new glycosphingolipids, thraustochytrosides A-C ( 1–3 ) were produced, in culture, by a marine protist, identified as Thraustochytrium globosum , collected in the Bahamas. Two-dimensional NMR methods, coupled with tandem mass spectrometry (MS-MS), were used to establish the structures of the new compounds.

Thraustochytrosides A—C: New Glycosphingolipids from a Unique Marine Protist, Thraustochytrium globosum.

Understanding the target and mode of action (MOA) of small molecules activity has become a critical feature in guiding the transition between drug discovery and clinical evaluation. While classically placed at the latter stages of a discovery program, we now describe how addressing the mode of action of natural products at the early stages of a program provides an important vehicle to inform the drug discovery process. In this review, we outline a streamlined cellular and molecular biological system and explore its utility through a series of four cases studies. We believe that this approach offers critical lessons to guide future drug discovery programs.

/pdf/elucidating-the-mode-of-action-of-marine-natural-products-tmy2uy3ezm.pdf

William Fenical

Papers

The Junceellolides: New Antiinflammatory Diterpenoids of the Briarane Class from the Chinese Gorgonian Junceella fragilis.

Response to Comment on “A commensal strain of Staphylococcus epidermidis protects against skin neoplasia” by Nakatsuji et al.

Novel polyol macrolide antitumor-antibiotics from the novel marine actinomycete strain cnq140

Thraustochytrosides A—C: New Glycosphingolipids from a Unique Marine Protist, Thraustochytrium globosum.

Elucidating the mode of action of marine natural products through an immunoaffinity fluorescent (IAF) approach