Neue Pyoverdin-Siderophore ausPseudomonas putida C

Abstract

New Pyoverdin Siderophores from Pseudomonas putida C Four new pyoverdins (C 2A, C 2B, C 3A, C 3B) were isolated from cultures of Pseudomonas putida C. Their structures were elucidated by chemical and spectroscopic methods. The compounds consist of a chromophore – (1S)‐5‐amino‐2,3‐dihydro‐8,9‐dihydroxy‐1H‐pyrimido [1,2‐a]quinoline‐1‐carboxylic acid – substituted at the amino group with a dicarboxylic acid or its amide. The carboxyl group of the chromophore is amidically bound to the N‐terminus of L‐Asp‐D‐[N5‐hydroxy‐N5‐(D‐β‐hydroxybutyryl)] Orn‐D‐Dab‐L‐Thr‐Gly‐D‐Ser‐L‐Ser‐L‐threo‐β‐hydroxy‐Asp‐L‐Thr. The four pyoverdins differ only in the nature of the dicarboxylic acid (amide), viz. L‐malamoyl‐ (C 2A), succinamoyl‐ (C 2B), L‐3‐carboxy‐2‐hydroxypropanoyl‐ (C 3A) or 3‐carboxypropanoyl (C 3B) residue. The hydroxamate function consists of N5‐hydroxy‐Orn and β‐hydroxybutyric acid, a structural unit which has been encountered for the first time in a pyoverdin.

Characterization of the chromophores of pyoverdins and related siderophores by electrospray tandem mass spectrometry

“…Succinic acid is symmetrical and for glutamic acid and ketoglutaric acid the binding site had been established by chemical degradation. For malic acid some not really convincing and partially contradicting NMR arguments had been advanced (Seinsche et al 1993). Commonly attachment to the chromophore NH 2 -group by the carboxyl group neighboring the CH 2 is formulated.…”

Secondary metabolites from fluorescent pseudomonads

“…Free succinic acid is a hydrolysis product. Malamide has been found to co-occur with succinamide [21] in 216 accordance with the progress in the citric acid cycle. [45].…”

“…The complexing constants of pyoverdins lie between 1024 and ]0 26 at pH 7.0 and between 10 17 and 102o at pH [12][13][14]27,28,34]. Asp-BuOHOrn-Dab-Thr-Gly-Ser-Ser-OHAsp-Th r [21 ] Ser-Lys-Gly-FoOHOrn-Lys-FoOHOrn-Ser Ser-Lys [22] _Al_a_-L_ys-Gly-Oly-OtL~s_p-_G_ln_-_Da_b-SersA_la-cOH_Orn G i n / D a b , c O H O r n [38] h.…”

“…Malic acid is bound by its /3-carboxyl group [15,21]. In solution amides of o~-ketoglutaric acid form equilibria between various open and cyclic forms [9,13,32] which can be separated by HPLC [40].…”

Microbial Siderophores

“…For glutamic and 2-oxoglutaric acid the binding to the chromophore by their g-carboxyl groups has been established by chemical degradation (124). For malic acid some not really convincing and partially contradictory NMR arguments have been advanced (319) for the binding by the carboxyl group neighboring the CH 2 group. Recently mass spectrometric arguments were reported suggesting a binding via the other carboxyl group (45).…”