Example of Soft (but highly useful) Information Available on the Internet.

Refer: Structure Determination by Powder Diffractometry Round Robin [http://fluo.univ-lemans.fr:8001/SDPDRR/]

Searching on the molecular formula for sample 2. using "Inference find" (http://www.inference.com/infind/ - C22H24N2O8 - and C22H24N2O8.HCL) reveals not only the name and connectivity in pages such as TR-344 Toxicology and Carcinogenesis Studies of Tetracycline Hydrochloride (CAS No. 64-75-5) in F344/N Rats and B6C3F1 Mice (Feed Studies) (http://ntp-server.niehs.nih.gov/htdocs/LT-studies/tr344.html) but also a starting molecule in MDL Mol File format (http://ntp-server.niehs.nih.gov/htdocs/structures/3d/TR344.mol) | [local].

- - - - Gif from Webpage - - - - - Chemdraw derived MDL Mol file Directly in Rasmol

Compared to Connectivity Derived from Expensive Commercial Database