GRAINS-Soybeans down as record Brazilian crop could capture Chinese sales

* Prospect of record Brazilian soybean crop weakens prices * Cheap Russian wheat offered despite political risk * Stronger dollar trend weighs on grains and soybeans * Corn follows wheat down (Recasts with weakness in European trade, adds new comment, changes dateline) By Michael Hogan HAMBURG, Feb 16 (Reuters) – Chicago soybean, wheat and corn fell on Thursday, with the stronger trend in the dollar hampering export prospects for U.S. supplies at a time of intensifying competition, especially from Brazilian soybeans and Russian wheat. Chicago Board of Trade most-active soybeans were down 0.1% to $15.23-3/3 a bushel at 1211 GMT….