(R)-mandelate + NAD(+) <=> phenylglyoxylate + NADH + H(+)
(r)-mandelate + nad(+) <=> phenylglyoxylate + nadh + h(+)
(R)-mandelate + NAD(+) <=> phenylglyoxylate + NADH + H(+)
(r)-mandelate + nad(+) <=> phenylglyoxylate + nadh + h(+)