Distribution and seasonal variation of allohydroxy-l-proline in Santalum album L

Abstract

AlloHydroxy-L-proline is widely distribu- ted in the genus Santalum. existing largely in the free state. The distribution of allohydroxy-L-proline in the sandal tree has been studied in the vegetative and reproductive phases of growth. In the former stage the imino acid content is highest in the apical leaves of any one branch, whereas in the latter stage the pericap of the green fruit contains a remarkable high concentration of the free imino acid. Buds and flowers also contain large amounts of the imino acid. Fruit ripening is accompanied by a steady decline in the allohydroxy-L-proline content of the pericap and a concomitant increase in that of the seed. The seasonal distribution of allohydroxy-L-proline in a healthy and in a diseased ("spiked") tree has been studied. The content in the leaves of the spiked tree was uniformly higher than that of leaves from the healthy one. The amount of allohydroxy-L-proline present in healthy leaves reached a peak value just before the onset of flowering. Drying of sandal leaves at relatively low temperatures (50[degree]) or stronger them at room temperature causes an increase in the content of allohydroxy-L-proline. The increase is apparently not due to protein breakdown. Preliminary investigations suggest that ornithine and glutamic acid and, under certain conditions, proline are the likely precursors of allonydroxy-L-proline in the sandal tree.