   0-Angeloylretronecine (**0**)      \+                    \+              \+                 \+   \+   \+   0-Angeloylretronecine (**0**)      \+                    \+              \+                 \+   \+   \+   0-Tigloylretronecine (**0**)       \+                    \+              \+                 \+   \+   \+   0-Tigloylretronecine (**0**)       \+                    \+              \+                           