Convert from dalton to zentner [Germany]

Unit Definition (dalton)
The dalton is an alternate name for the unified atomic mass unit (u or amu). The dalton is often used in microbiology and biochemistry to state the masses of large organic molecules; these measurements are typically in kilodaltons (kDa). It seems necessary to have such a unit, since "kilo-amu" would be such a clumsy name. The SI accepts the dalton as an alternate name for the unified atomic mass unit and specifies Da as its proper symbol. The unit honors the English chemist John Dalton (1766-1844), who proposed the atomic theory of matter in 1803.

Unit Definition (zentner [Germany])
The zentner is a traditional German unit of weight or mass, comparable to the traditional quintal and to the English hundredweight. Similar units were used in Scandinavia. Originally the zentner was equal to 100 pfund, or German pounds. 100 pfund varied from 110 to as much as 120 pounds avoirdupois (49.9-54.4 kilograms), depending on the market. After the introduction of the metric system in Germany, the zentner was redefined to equal to exactly 50 kilograms, which is about 110.231 pounds. In English, the zentner is commonly spelled centner.