Trehangelin E, a bisacyl trehalose with plant growth promoting activity from a rare actinomycete Polymorphospora sp. RD064483.

Trehangelin E (1), a new bisacyl trehalose, was isolated from the culture extract of an actinomycete Polymorphospora sp. RD064483, along with three known congeners, trehangelins A, B, and D. Compound 1 is a new trehalose derivative acylated with (Z)-2-methyl-2-butenoic acid (angelic acid) at 3- and 6'-positions, as determined by NMR and MS analyses. Compound 1 promoted root elongation of germinated lettuce seeds by 30% at 1 μM and 90% at 10 μM compared to the nontreated seeds. Similar promoting activity of root elongation was also observed with trehangelins A and B at the same level.