No abstract

A novel metabolite was isolated from the culture supernatants of Rhodobacter sphaeroides OU5 when grown on L-tryptophan as sole source of nitrogen under photoheterotrophic conditions. It was identified by IR, NMR ((1)H, (13)C) and MS as an indole terpenoid ether [3-hydroxy-6-(1H-indol-3-yloxy)-4-methylhexanoic acid] and is named as rhodethrin. Rhodethrin at 0.5 microM gave positive test in auxin bioassay and initiated early rooting in tissue-cultured plants than IAA at 5 microM. Rhodethrin has cytotoxic activity against Sup-T(1) lymphoma and Colo-125 cancer cell lines at 10 nM.

An efficient total synthesis of (+)-goniodiol was illustrated by using Carreira alkynylation and Sharpless asymmetric dihydroxylation as key steps.

An enzyme involved in the catabolism of 3,4-dihydroxyphenylalanine (DOPA) was isolated from Rhodobacter sphaeroides OU5. The enzyme catalyzes the formation of 3,4-dihydroxyphenylpyruvic acid (DOPP) and ammonia from DOPA. Formation of ammonia by DOPA oxidative deaminase was O2 dependent and the enzyme isolated to its homogeneity has 100% affinity for DOPA. DOPA oxidative deaminase is functional at low concentrations of the substrate (< 100 micromol.L(-1)) and is independent of NADH. The molecular mass of the purified enzyme is approximately 190 kDa and the enzyme could be a pentamer of 54, 42, 34, 25, and 23 kDa subunits as determined by SDS-PAGE.