[Riboflavin and lumiflavin analogs and alloxazine derivatives. I. Effect on riboflavin synthesis by and growth of Bacillus subtilis].

Effect of riboflavin, lumiflavin and a number of alloxazine derivatives is studied on the growth of three Bacillus subtilis strains with different genetic state of riboflavin operon as well as their ability to show coenzyme and regulating properties characteristic of vitamin B2. The fission of the ribityl chain of the riboflavin molecule results in the complete loss of both coenzyme and regulating properties of vitamin B2 (analogues of lumiflavin and alloxazine derivatives). Different types of esterification of hydroxyl groups of ribityl chain or its replacement by dulcityl chain results in the decrease of regulating properties characteristic of riboflavin as an end product of biosynthetic pathway (tetraacetylriboflavin and its derivatives, tetrapropionyl- and tetrabutyrylriboflavin) or to the loss of coenzyme and regulating activities (galactoflavin and tetrabenzoylriboflavin). The length increase of hydrocarbon chain under esterification of hydroxyl groups in ribityl chain results in enhancing vitamin B2 non-specific inhibitory effect on the growth of Bacillus subtilis strains studied. The replacement of 8-CH3 group in the riboflavin molecule by amino- or D-ribitylaminogroup results in the formation of specific antimetabolites, 8-amino(nor)riboflavin and 8-D-ribitylamino(nor)riboflavin respectively. Depending on the nature of other alterations or replacements of the 8-CH3 group of riboflavin molecule and their combinations with alterations of ribityl chain the reduction of the regulating activity (8-alpha-bromtetraacetylriboflavin) or a sharp decrease of coenzyme and regulating functions (analogues N 9 to N 15) takes place. The replacement of riboflavin-5-N-oxide and 2-thioriboflavin type did not affect the studied properties of riboflavin.