Oocydin A, a chlorinated macrocyclic lactone with potent anti- oomycete activity from Serratia marcescens

Abstract

A unique chlorinated macrocyclic lactone, termed oocydin A, was isolated from a strain of Serratia marcescens growing as an epiphyte on Rhyncholacis pedicillata, an aquatic plant native to the Carrao river of the VenezuelanGuyanan region of South America. The lactone has a molecular mass of 470 Da, and contains one atom of chlorine, a carboxyl group and a tetrahydrofuran ring internal to a larger macrocyclic ring. MICs of approximately 003 µg ml N1were noted for oocydin A against such phytopathogenic oomycetes as Pythium ultimum, Phytophthora parasitica, Phytophthora cinnamomi and Phytophthora citrophora. With regard to the true fungi, oocydin A had either minimal or no effect against certain Fungi Imperfecti (including several pathogens of humans), two ascomycetes and a basidiomycete. Oocydin A may have potential as an antimycotic in agricultural applications and especially for crop protection.

Bacterial Biosynthetic Gene Clusters Encoding the Anti-cancer Haterumalide Class of Molecules

“…Besides the very high bioactivity that oocydin A shows against the oomycete, P. ultimum, we also tested its bioactive properties against fungal plant pathogens. In contrast to the report by Strobel et al (5), we observed that the halogenated molecule was also active against the fungus, V. dahliae, because all the producing strains show bioactivity against the fungus, whereas the A153 mutants defective in the ooc gene cluster had lost the anti-Verticillium activity ( Fig. 1H and supplemental Fig.…”

FR177391, A New Anti-hyperlipidemic Agent from Serratia

“…According to highresolution FAB-MS spectrometry, the molecular formula is C 23 H 31 ClO 8 . In the 13 C NMR spectrum, all the 13 C signals were consistent with the carbon backbone presented in Fig. 2 (1).…”

“…2. The structure has been reported as those of haterumalide NA [11] and oocydin A [13]. However, the optical rotation of FR177391 (ϩ32 : c0.85, MeOH) was distinct from those of haterumalide NA (Ϫ3.0 : c0.053, MeOH) and oocydin A (ϩ18.2 : c0.22, MeOH), indicating that the absolute structure of FR177391 is different from those of haterumalide NA and oocydin A.…”

“…The mass spectrum was recorded with VG ZAB-SE mass spectrometer. 1 H NMR (400 MHz) and 13 C NMR (100 MHz) spectra were acquired with a Bruker AM400wb spectrometer controlled with an ASPECT 3000 computer.…”

Endophytes: exploiting biodiversity for the improvement of natural product-based drug discovery

“…Still, the plant population remained quite healthy. Upon extraction and investigation of the endophytic flora of R. penicillata, a potent antifungal bacterium, Serratia marcescens, was identified, which in turn was shown to produce oocydin A (Figure 8), a novel anti-oomycetous compound that obviously provided the plant with the requisite protection from the water molds (Strobel et al 1999).…”