"Death before dishonor" in Klingon.
It's not really a trivial translation. No translation is, and I, in particular, can't leave anything with just one answer.
I think we have a toast actually invented by Marc Okrand, the inventor of the Klingon language, meaning "May you die before you are captured." That's {Dajonlu'pa' bIHeghjaj}. For "...before you are dishonored," it would be {bIquvHa'pa' bIHeghjaj}. It's hard to capture the immediacy and conciseness of the English, which really means something like "I would die rather than be dishonored, given the choice." You could say something like that in Klingon, but it would be as long-winded as the English, and not very pithy. Hmm... It departs from the English, but maybe {jIquvHa'Qo'! Hegh vImaS!}: "I refuse to be dishonored. I prefer death!"
For literalness, something like {jIquvHa'pa' jIHegh} is close (before I am dishonored, I die), though may sound more like a statement of fact. Or in "clipped" form {quvHa'pa' Hegh}, which could apply to anyone.