Previously, we reported an interesting reaction by which esculeogenin A [(5a a,22S,23S,25S)-3b b,23,27-trihydroxyspirosolane], a sapogenol of tomato-saponin, esculeoside A, was easily converted into a pregnane derivative, 5a a-pregn-16-en-3b b-ol-20-one, merely by refluxing with pyridine and water. Its chemical mechanism including air oxidation is here described.

No abstract

The purpose of our research is information access support based on the contents of a comic book. For this purpose, it is necessary to obtain information related to the story and the characters. In our previous research, we extracted the information using a review sentence and built a comic search system based on the extraction results. This system determined the relationship between comics using the TF-IDF method. However, the TF-IDF method cannot take into account the meaning of each word included in the review sentence. Therefore, this system may not be able to provide accurate results based on comic relationships. In this study, we analyze the review sentence using a hierarchical topic classification. On the other hand, the extracted topics often contain words that hinder the user from guessing the contents of the comic. Especially, the named entities defined in the comic tend to cause the problem. The amount of information obtained by the user varies greatly based on the user's knowledge about the named entities. Therefore, we investigated the influence of the named entity extracted from the comic reviews as the feature words. Our experiment revealed that the user's understandability was improved when the proportion of the named entities was decreased. Furthermore, we build an exploratory search system based on the topic.