The present invention relates to a process for producing a beer tittering agent via enzyme catalyzed bioconversion of hop-derived isoalpha acids to dihydro-(rho)-isoalpha acids and to the novel enzyme catalysts which may be employed in such a process.

The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

The present invention relates to a process for producing a beer littering agent via enzyme catalyzed bioconversion of hop-derived isoalpha acids to dihydro-(rho)-isoalpha acids.

The present invention relates to a process for producing a beer littering agent via enzyme catalyzed bioconversion of hop-derived isoalpha acids to dihydro-(rho)-isoalpha acids.

The present invention relates to a process for producing a beer bittering agent via enzyme catalyzed bioconversion of hop-derived isoalpha acids to dihydro-(rho)-isoalpha acids.

The present invention relates to a process for producing a beer bittering agent via enzyme catalyzed bioconversion of hop-derived isoalpha acids to dihydro-(rho)-isoalpha acids.

A racemic or optically enriched compound of Formula 1:

##STR00001## wherein P is H or a protective group for hydroxyl groups; and X is Cl, Br, I, or CH.sub.2CH.sub.2CH.sub.2COOR.sub.1, wherein R.sub.1 is C.sub.1-7-alkyl or C.sub.7-11-aralkyl.