Conversion of the spirosolane-type glycoside, esculeoside A, a major component contained in the ripe tomato Lycopersicon esculentum fruits, into a solanocapsine-type sapogenol, esculeogenin B-2, (5alpha,22S,23R,25S)-22,26-epimino-16beta,23-epoxy-3beta,23,27-trihydroxycholestane, and esculeogenin B-1, (5alpha,22R,23S,25S)-22,26-epimino-16beta,23-epoxy-3beta,23,27-trihydroxycholestane, which are ...

The aim of this report is to present a new two-piece thyroid-neck phantom produced by the concurrent use of epoxy resin and poly(methyl methacrylate) (PMMA: plexiglass) soft tissue equivalent materials. Accordingly, mass attenuation coefficients of the epoxy resin and the plexiglass compounds were obtained from simulation (NIST XCOM 3.1) and measurements (practical dosimetry) and compared to th...

A methylene chloride extract of the pulp of Annona muricata L. was fractionated in search for scarcely functionalized Annonaceous acetogenins (type E). Previously known C-35 and C-37 mono-epoxy unsaturated compounds, epomuricenins-A and -B (1+2) and epomusenins-A and -B (3+4), were obtained. Two new mono-epoxy saturated C-35 representatives, epomurinins-A and -B (5+6) were also isolated.

Research for a reliable solid-form semiconductor neutron detector continues because such a device would have greater efficiency, in a compact form, than present day gas-filled He and BF3 detectors. The Li(n,t)He reaction yields a total Q value of 4.78 MeV, larger than B, and easily identified above background radiations. Hence, devices composed of either natural Li (nominally 7.5% Li) or enrich...

Three new megastigmane glucopyranosides, komaroveside A [(3S,4R,5Z,7E)-3,4-dihydroxy-5,7-megastigmadien-9-one-3-O-β-D-glucopyranoside] (1), komaroveside B [(3S,4S,5S,6R,7E)-5,6-epoxy-3,4-dihydroxy-7-megastigmen-9-one-3-O-β-D-glucopyranoside] (2) and komaroveside C [(3S,4S,5S,6R,7E,9S)-5,6-epoxy-3,4,9-trihydroxy-7-megastigmen-3-O-β-D-glucopyranoside] (3) were isolated, together with eight known ...

A phytochemical study of an ethanol-soluble extract from the root barks of Daphne tangutica Maxim., a traditional Tibetan herb medicine, led to the isolation of 30 compounds, including eight daphnane diterpenes, nine coumarines, six lignans, five phenylpropanoid derivatives, beta-sitosterol and p-hydroxy benzonate. Two compounds out of these isolates are new daphne diterpene analogs, and their ...

Three new macrocyclic diterpenes, kansuinins F (1), G (2), and H (3), together with four known jatrophane diterpenes, kansuinins D (4), E (5), and A (6) and 3beta,5alpha,7beta,15beta-tetraacetoxy-9alpha-nicotinoyloxyjatropha-6(17)-11E-dien-14-one, were isolated from the roots of Euphorbia kansui. Compounds 1 and 2 were assigned as 6(17)-en-11,12-epoxy-14-one-type jatrophane diterpenes, and comp...

The presence of thermal mismatch between different materials of plastic IC packages was found to cause reliability and moldability issues such as delamination and warpage phenomenon. Delamination and warpage between the mold compound and die attach adhesive material were evaluated for Quad Flat No-lead (QFN) package. Evaluation was conducted on two set of different materials combination of epox...

Two new eudesmane sesquiterpenes, 2alpha-hydroxy pterodontic acid (1) and pterodolide [3alpha-(2-methyl-2,3-epoxy)-butyric-4alpha-acetoxy-8beta-ethoxy eudesma-7(11)-en-8alpha,12-olide (2), along with five known compounds (3-7) were isolated from the aerial parts of Laggera pterodonta. Their structures were elucidated on the basis of spectroscopic methods. The immunosuppressive activity of the i...

Herein we shed light on the mechanism of the reaction of epoxides with ammonium thiocyanate to give the corresponding thiiranes in water, and we present a computational mechanistic model for this highly useful reaction.