AIDS-005404 AIDS005404 Penicillin Et(NH)2 dimer [2R-[2.alpha.(R*),4.-beta.-]]-4,4'-[1,2-Ethanediylbis[aminocarbonyl]]bis[5,5-dimethyl-.alpha.-[[(1,1'-biphenyl-2-yl)carbonyl]amino]-N-(caboxymethyl)-2-thiazolidineacetamide]