What Sarge posted tells you what Pennzane is. Pennzoil used it as a marketing tool in one of their synthetics years ago. Pennzane is a very expensive product and there was just enough in the oil to say it was. Not enough to make any difference.
Z-7 is a very old trademark of Pennzoil. Nothing magic either. The Z is the Z in PennZoil and the 7 was the 7 additives used in the oil (detergents, antifoam, etc.)