4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 3,3-dimethyl-7-oxo-6-(sulfoamino)-, disodium salt, (2S-(2alpha,5alpha,6beta))- 6-Sulfoaminopenicillanic acid disodium 83671-00-5 FR-900318 disodium salt