Pyropia haitanensis polysaccharide extends lifespan by inhibiting protein aggregation in Caenorhabditis elegans

Pyropia haitanensis polysaccharide(LP)have been found for having many excellent functions such as anti-aging.Using Caenorhabditis elegans models,we evaluated the anti-aging activity of LP by observing the lifespan,reproduction,pharyngeal pumping,stress response,quantitative fluorescence of polyglutamic acid,and nuclear localization of DAF-16 of worms.The results reveal that LP could extend the adult lifespan of wild-type and polyQ nematodes,indicating a connection of its anti-aging benefit with the toxicity-suppressing effect.The number of polyglutamic acid aggregates in high concentration groups decreased by 24.39%(P<0.05)to the control.The high-dose group strongly induced DAF-16 nuclear translocation over intermediate and cytosolic localizations compared with the control(P<0.001).Therefore,we believe that LP could extend the lifespan and reduce the protein aggregation in C.elegans through nuclear DAF-16∷GFP expression.

Structural diversification of phenylspirodrimane lactams by employing a biosynthetic intermediate

Phenylspirodrimanes are a kind of meroterpenoids with structural diversity and complexity,exhibiting a wide of biological properties,especially for the lactam derivatives consisting a y-lactam moiety and N-linked side chains.These compounds were derived from multi-step combination of enzymatic and non-enzymatic conversions of intermediates in their biosynthetic pathways.Stachbotrydial(2)with an o-phthalaldehyde unit was supposed as the high-reactivity intermediate of phenylspirodrimane lactams via nonenzymatic reaction with amines.In the present work,an effective and non-enzymatic diversification strategy was developed for the structural diversification of phenylspirodrimane lactams including monomers and dimers from 2 by feeding structurally various mono-and diamines in the fungus Stachybotrys chartarum cultures.In total,24 phenylspirodrimane lactams(1,3-25)including 18 new compounds were synthesized.Among them,stachybocin A(1),a bioactive phenylspirodrimane lactam dimer,was produced with the yield of 18.7 mg/g of cell dry weight.The structures of these compounds were elucidated by extensive spectroscopic data,single-crystal X-ray diffraction(Cu Kα),and calculated electronic circular dichroism(ECD)analyses.Bioassay revealed that compounds 1,17,and 24 displayed significant inhibitory effect on the inactivated state of hNav 1.2 channels with IC_(50) values of 0.22,2.08,and 0.53μmol/L,respectively.In addition,1 showed potent protein tyrosine phosphatase 1B(PTP1B)inhibitory N-methyl-b-aspartate(NMDA)receptor antagonistic,and anti-inflammatory activities.