Cyathane diterpenes from Sarcodon cyrneus and evaluation of their activities of neuritegenesis and nerve growth factor production

Two new cyathane diterpenes, cyrneine C (4) and D (5), were isolated from the mushroom Sarcodon cyrneus, along with previously isolated cyrneine A, B and glaucopine C. The structures of the novel diterpenoids were determined by the analysis of spectroscopic data. Effects of the cyrneines and glaucopine C on the NGF gene expression in 1321N1 cells and on neurite outgrowth on PC12 cells were evaluated.     

Furfural formation from d-xylose: the use of different halides in dilute aqueous acidic solutions allows for exceptionally high yields

Starting from the results achieved in a previous work on the effects of Cl⁻ ions on furfural formation in aqueous acid solution [Marcotullio, G. et al., Green Chem.2010, 12, 1739], the general effect of different halides is addressed. Experimental results show the halides to influence at least two distinct steps in the reaction leading from d-xylose to furfural under acidic conditions, via different mechanisms. The nucleophilicity of the halides appears to be critical for the dehydration, but not for the initial enolization reaction. By combining different halides synergic effects become evident resulting in very high selectivities and furfural yields.     

Suppressors of hedgehog signaling

Subversion of signals that physiologically suppress Hedgehog pathway results in aberrant neural progenitor development and medulloblastoma, a malignancy of the cerebellum. The Hedgehog antagonist RENKCTD11 maps to chromosome 17p13.2 and is involved in the withdrawal of the Hedgehog signaling at the granule cell progenitor transition from the outer to the inner external germinal layers, thus promoting growth arrest and differentiation. Deletion of chromosome 17p, the most frequent genetic lesion observed in this tumor, is responsible for the loss of function of RENKCTD11, resulting in upregulated Hedgehog signaling and medulloblastoma. Persistence of signals that limit Hedgehog activity is also associated with malignancy. Hedgehog signaling- induced downregulation of ErbB4 receptor expression is attenuated in medulloblastoma subsets in which the extent of Hedgehog pathway activity is limited, thus favoring the accumulation of ErbB4 with imbalanced alternative splice CYT-1 isoform over the CYT-2. This is responsible for both Neuregulin ligand-induced CYT-1-dependent prosurvival activity and loss of CYT-2-mediated growth arrest.