Two new alkaloids, oryzadiamines A and B (1 and 2), were isolated from the bran of an Oryza sativa mutant with yellow grains. The structures of 1 and 2 were elucidated with spectroscopic analyses. Oryzadiamines A and B (1 and 2) are new natural products possessing unique nitrogen-containing heterocyclic ring systems. Oryzadiamine A (1) may play a significant role in the yellow color of the grain.

中文翻译：

---

Oryzadiamines A和B，从生物碱稻与黄色晶

从带有黄色颗粒的水稻突变体的麸皮中分离出两种新的生物碱，米杂二胺A和B（1和2）。光谱分析阐明了1和2的结构。谷氨酰胺A和B（1和2）是具有独特的含氮杂环系统的新天然产物。米杂二胺A（1）可能在谷物的黄色中起重要作用。