Glycosylation enhances the anti-migratory activities of isomalyngamide A analogs

Antiangiogenic Effect of Isomalyngamide A Riboside CY01 in Breast Cancer Cells via Inhibition of Migration, Tube Formation and pVEGFR2/pAKT Signals

BACKGROUND

To block the metastatic and angiogenic pathways during the tumor progression arouses considerable pharmacological interests in the development of anticancer drugs.

OBJECTIVE

To develop alternative antiangiogenic and antimetastic agents, we designed and prepared a series of nature inspired isomalyngamide A analogs containing ribose conjugate with 1,2-diaminoethane or 1,3- diaminopropane linkers (1-8).

METHODS

The target glycosylated isomalyngamide A analogs 1-8 were constructed through condensation of the malonic acids 16-19 and the corresponding aminoethoxyl ribosides 20 and 21, using HBTU/DIPEA as the coupling agent. The cell growth inhibition assay, cell migration assay, transwell invasion assay, adhesion assay, tube formation assay and western blot analysis were used to validate the biological actions of compounds.

RESULTS

The most effective compound, isomalyngamide A riboside 1 (CY01), possessing a D-ribose core structure and a 1,3-diaminopropane linker, showed significant suppression of MDA-MB-231 cell migration and inhibited tube formation of Human Umbilical Vascular Endothelial Cells (HUVECs) in a dose-dependent manner. Effect of the latter is comparable to that of sorafenib, an orally active multikinase inhibitor and an inhibitor of angiogenesis. CY01 also showed slight inhibition on collagen type IV- and laminin-mediated cell adhesion. These actions may be regulated through the blockade of the VEGF/VEGFR2 signaling pathway by inhibiting the VEGF induced phosphorylation of p-VEGFR2 and p-AKT.

CONCLUSION

In this effort, we have discovered synthetic and glycosylated marine metabolites which may serve as an alternative antiangiogenic and antimetastic agent during multitherapy.

Glycorandomization: A promising diversification strategy for the drug development

Glycorandomization is a natural product derivatization strategy in which different sugar moieties are linked to the aglycone part of the naturally existing glycosides to create glycorandomized libraries. Sugars attached to the natural products are responsible for affecting their solubility, mechanism of action, target recognition, and toxicity and thus, by changing the sugar part, these properties could be modified. Glycorandomization can be done via two approaches (i) a synthetic approach known as neoglycorandomization, and (ii) chemoenzymatic approach including in-vitro and in-vivo glycorandomization. Glycorandomization can be a promising technology for the drug discovery that has proved its potential to improve pharmacokinetic (solubility) and pharmacodynamic profile (mechanism of action, toxicity, and target recognition) of the parent compounds. The substrate flexibility of glycosyltransferases and other enzymes towards sugars and/or aglycone substrates has made this technique versatile. Further, the enzymes can be altered by genetic engineering to generate glycorandomized libraries of diverse natural product scaffolds. This technique has the potential to produce new compounds that can be helpful to the mankind by treating the threatening disease states. This review covers the different strategies for glycorandomization as a tool in drug discovery and development. The fundamentals of glycorandomization, different types, and further development of differentially glycorandomized libraries of natural products and small molecule based drugs have been discussed.

One-Pot Synthesis of Rotationally Restricted, Conjugatable, BODIPY Derivatives from Phthalides

O-Ethylation of phthalides with Meerwein's reagent followed by reaction of the ensuing salts with pyrrole, results in the formation of 5-alkoxy-5-phenyl dipyrromethane derivatives, which function as ready precursors of ortho-substituted 8-aryl BODIPY derivatives by reaction with borontrifluoride etherate, an overall process that can be carried out in a one-pot operation.

Chemical compounds toxic to invertebrates isolated from marine cyanobacteria of potential relevance to the agricultural industry

In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.