Abstract: Among commonly known 3?,3?-cGAMP is a lyophilized product. The lyophilized product needs a lyophilizer during the manufacture. This, itself, causes a limitation in scale-up for mass production. Thus, it has been desired to develop and obtain a large amount of their crystals in a simple manner without using a special apparatus such as a lyophilizer. In addition, conventionally known lyophilized products or ethanol precipitates are highly hygroscopic. Hence, the present invention addresses the problem of providing an easy-to-handle crystal with excellent shelf life. A hydrate crystal of 3?,3?-cGAMP according to the invention may be either a crystal of alkali metal salt or a crystal of free acid. Either is less hygroscopic than existing powder. Thus, each is easy to handle in various purposes and is thus useful as a pharmaceutical raw material or the like.

Abstract: Among commonly known 3?,3?-cGAMP is a lyophilized product. The lyophilized product needs a lyophilizer during the manufacture. This, itself, causes a limitation in scale-up for mass production. Thus, it has been desired to develop and obtain a large amount of their crystals in a simple manner without using a special apparatus such as a lyophilizer. In addition, conventionally known lyophilized products or ethanol precipitates are highly hygroscopic. Hence, the present invention addresses the problem of providing an easy-to-handle crystal with excellent shelf life. A hydrate crystal of 3?,3?-cGAMP according to the invention may be either a crystal of alkali metal salt or a crystal of free acid. Either is less hygroscopic than existing powder. Thus, each is easy to handle in various purposes and is thus useful as a pharmaceutical raw material or the like.