A new furostanol saponin from <i>Dendrobium chrysanthum</i> Lindl. with cytotoxic activity

<p>A new furostanol saponin, (25<i>R</i>)-26-<i>O</i>-(<i>α</i>-d-glucopyranosyl)-(1→2)-<i>α</i>-l-rhamnopyranosyl-furost-5-ene-3<i>β</i>, 22<i>α</i>, 26-triol-3-<i>O</i>-<i>α</i>-d-glucopyranoside (<b>1</b>), together with four known compounds <b>2–5</b> were isolated from the ethanolic extract of the stems of <i>Dendrobium chrysanthum</i> Lindl<i>.</i> The structures of these new compounds were identified by extensive spectroscopic analysis including 1D and 2D NMR and HR-ESI-MS, as well as chemical methods. Compounds <b>1–3</b> were isolated from <i>D. chrysanthum</i> for the first time. Furthermore, the inhibitory effects of the compounds on tumor cells were evaluated, and compounds <b>1–2</b> exhibited significant cytotoxic activities potentially against SPC-A1, MCF-7 and HeLa human cancer cell lines. Compounds <b>3–5</b> showed inhibitory activity against the SPC-A1 and MCF-7.</p

Matched Coupling of Propargylic Carbonates with Cyclopropanols

The ring opening–coupling reaction of cyclopropanols with propargylic carbonates affording synthetically attractive allenyl ketones has been developed. The mechanism involves the ligand-exchange reaction of in situ formed allenyl palladium methoxide with cyclopropanols followed by carbon–carbon bond cleavage and reductive elimination. The reactions proceeded smoothly under mild reaction conditions with Pd(0)/XPhos catalysis in the absence of any external base and displayed a wide scope and application to a steroidal skeleton. The efficiency of chirality transfer and synthetic utility of the allene products have also been demonstrated

Large scale newborn deafness genetic screening of 142,417 neonates in Wuhan, China

<div><p>Almost one third of the three million people in China suffering severe deafness are children, and 50% of these cases are believed to have genetic components to their etiology. Newborn hearing genetic screening can complement Universal Neonatal Hearing Screening for the diagnosis of congenital hearing loss as well as identifying children at risk for late-onset and progressive hearing impairment. The aim of this joint academic and Ministry of Health project was to prototype a cost effective newborn genetic screen in a community health setting on a city-wide level, and to ascertain the prevalence of variation at loci that have been associated with non-syndromic hearing loss. With the participation of 143 local hospitals in the city of Wuhan, China we screened 142,417 neonates born between May 2014 and Dec. 2015. The variants GJB2 c.235delC, SLC26A4 c.919-2A>G, and mitochondrial variants m.1555A>G and m.1494C>T were assayed using real time PCR. Newborns found to carry a variant were re-assayed by sequencing in duplicate. Within a subset of 707 newborns we assayed using real-time PCR and ARMS-PCR to compare cost, sensitivity and operating procedure. The most frequent hearing loss associated allele detected in this population was the 235delC variant in GJB2 gene. In total, 4289 (3.01%) newborns were found to carry at least one allele of either GJB2 c.235delC, SLC26A4 c.919-2A>G or two assayed MT-RNR1 variants. There was complete accordance between the real-time PCR and the ARMS PCR, though the real-time PCR had a much lower failure rate. Real-time PCR had a lower cost and operating time than ARMS PCR. Ongoing collaboration with the participating hospitals will determine the specificity and sensitivity of the association of the variants with hearing loss at birth and arising in early childhood, allowing an estimation of the benefits of newborn hearing genetic screening in a large-scale community setting.</p></div

Flow chart of neonates’ deafness gene screening.

<p>Flow chart of neonates’ deafness gene screening.</p

Genotype results comparison of the PCR methods.

<p>Genotype results comparison of the PCR methods.</p

Sequencing primers for four NSHL associated loci.

<p>Sequencing primers for four NSHL associated loci.</p

Failure rate of ARMS-PCR method.

<p>Failure rate of ARMS-PCR method.</p

Comparison of carrier frequency of mutations associated with hearing loss in 21 cities in China.

<p>Comparison of carrier frequency of mutations associated with hearing loss in 21 cities in China.</p

Frequency of compound-mutations among 142,417 neonates.

<p>Frequency of compound-mutations among 142,417 neonates.</p

Failure rate of real-time PCR.

<p>Failure rate of real-time PCR.</p