Abstract: Pyridine derivatives useful for preventing or treating peptic ulcers, pharmaceutical preparations and methods of treating peptic ulcers are disclosed.

Abstract: A pyridinium salt useful as an antiulcer agent, defined by formula (I) is disclosed. It includes a sulphenamide compound and a pyridinium compound. J is benzimidazole, K is --S-- or --SSR-- and Z is hydroxy or alkoxy.

Abstract: There are disclosed polyprenyl sulfone derivatives of the general formula: ##STR1## wherein n represents an integer of 1-4, R.sub.1 represents an aryl group d R.sub.2 represents a hydroxymethyl or carboxyl group. The polyprenyl sulfone derivatives are prepared by cultivating a microorganism of the genus Nocardia capable of oxidizing a compound of the general formula: ##STR2## wherein n and R.sub.1 have the same meanings as defined above, in a culture medium containing a compound of the above general formula (II), and then collecting the oxidation product from the culture mixture. The polyprenyl sulfone derivatives are useful as intermediates for preparing various useful polyprenyl compounds.