Apache to Nginx rewrite rules

Apache to Nginx rewrite rules

I have Apache rules for a Web application that look like so:
RewriteEngine On
RewriteRule ^unsubscribe/([-A-z0-9]+)/?(.*)$
/list/unsubscribe.php?id=$1&why=$2 [L,QSA]
RewriteRule ^unsub/([-A-z0-9]+)/?(.*)$ /list/subscribe.php?id=$1&why=$2
[L,QSA]
I've tried:
rewrite ^unsubscribe/([-A-z0-9]+)/?(.*)$ /list/unsubscribe.php?id=$1&why=$2;
Which didn't seem to match and results in a 404.
location /unsubscribe {
rewrite ^/unsubscribe/([-A-z0-9]+)/?(.*)$
/list/unsubscribe.php?id=$1&why=$2 break;
}
Results in serving the file, but without PHP processed
http://sg.hackandtell.org/unsubscribe/foo/bar
Perhaps can someone recommend some debug strategies?