* Cerus Corp., of Concord, Calif., received a $5 million equity investment from Baxter International Inc., of Deerfield, Ill., which received FDA approval for a Phase III trial of a platelet pathogen inactivation system developed by Cerus. The companies' agreement provides for two more $5 million equity investments when milestones are attained. Cerus' product is designed to make blood transfusions safer by deactivating infectious pathogens in blood components.

* Organogenesis Inc., of Canton, Mass., declared a 25 percent stock dividend. One share of common stock will be issued for every share owned, and no fractional shares will be issued. After the dividend, the company will have about 23 million shares outstanding, with 40 million authorized for issuance.

* The Scripps Research Institute, of La Jolla, Calif., has performed the first total chemical synthesis of potential antiancer compounds isolated from rare species of corals and related marine organisms. Scientists assembled the compounds by designing a multistep strategy using simple chemical building blocks, such as carvone, an oil from caraway or dill seeds. They hope to produce synthetic analogues for biological screening purposes that could lead to more effective and safer therapeutic agents than the original compounds.

* Terrapin Technologies Inc., of South San Francisco, completed a second closing of its private equity financing, receiving an additional $1.05 million from current and new investors. The amount brings the total raised in the most recent financing to $7.15 million, which will fund operations into 1999. Terrapin uses its proprietary chemoinformatics technology, which classifies and screens chemicals, with a diverse library of small molecule compounds to develop product leads.