A light color or a low color rosin or a rosin ester composition is disclosed. Significant color improvement can be obtained for a low color rosin, or a rosin ester by using a co-catalyst. In one embodiment, the co-catalyst has a triplet formation quantum yield (ϕ T ) of greater than 0.5 and a triplet lifetime (τ T ) of greater than 0.5 microseconds In another embodiment, the co-catalyst is selected from acridone, anthrone, 9-fluorenone, thioxanthone, xanthone, derivatives and combinations thereof.

Light rosin ester compositions and methods of making same

The invention provides a tandem cyclization synthesis method of large-steric hindrance xanthone and derivatives thereof. The tandem cyclization synthesis method is characterized in that at 135-145 DEGC, according to an equivalent ratio of a compound shown as a general formula I to a compound shown as a general formula II of (1-2):(1-3), performing a reaction on the compound shown as the general formula I and the compound shown as the general formula II under the reactions of a copper catalyst and a triphenylphosphine additive to produce a compound shown as a general formula III, wherein the compound shown as the general formula I is as shown in the description, the compound shown as the general formula II is as shown in the description, the compound shown as the general formula III is asshown in the description, and in the general formulae, at least one of R1, R2, R3 and R4 is isopentenyl. By the tandem cyclization synthesis method, fragments at the two ends of a large-steric hindrancexanthone natural product compound are established respectively, an acylation tandem cyclization reaction is performed under copper catalysis, and synthesis of the large-steric hindrancexanthone natural product and the derivatives thereof is efficiently achieved.

Tandem cyclization synthesis method of large-steric hindrance xanthone and derivatives thereof

Use of sparstolonin B in inhibition of growth and/or viability of human neuroblastoma cells is described. The sparstolonin B can be naturally derived from the Chinese herb Sparganium stoloniferum or can be synthetic. The sparstolonin B is shown to be effective both in vitro and in vivo in inhibition of growth and/or viability of neuroblastoma cells of multiple different genetic backgrounds including N-myc amplified with wild p53 neuroblastoma cells, N-myc amplified with mutated p53 neuroblastoma cells, and N-myc nonamplified neuroblastoma cells.

Sparstolonin B based pharmaceutical agent for neuroblastoma treatment

Methods are provided for forming a xanthone derivative via reacting a 2-substituted benzaldehyde with a phenol derivative to form the xanthone derivative.

Qian Wang

Papers

Methodology for the synthesis of xanthones