New Insecticidal Antibiotics, Hydroxyfungerins A and B, Produced by Metarhizium sp. FKI-1079

Abstract

New insecticidal antibiotics designated hydroxyfungerins A and B were isolated from the culture broth of a fungal strain Metarhizium sp. FKI-1079 together with a known compound, fungerin. The structures of hydroxyfungerins A and B were elucidated by spectroscopic studies including various NMR experiments. Hydroxyfungerins A and B showed growth inhibitory activity against brine shrimps, Artemia salina.Keywords fungerin, insecticidal, brine shrimp, fungi, Metarhizium sp. IntroductionOur research group has focused on discovery of biological active compounds from microbial metabolites [1ϳ8]. In the course of our screening program for insecticidal antibiotics, we found that a fungal strain FKI-1079, which was isolated from soil collected at Yakushima, Kagoshima Prefecture, Japan, produced two new insecticidal antibiotics, named hydroxyfungerins A (2) and B (3), along with the known compound, fungerin (1) [9] (Fig. 1). The strain was identified as Metarhizium sp. from morphogical characteristics. Compounds 2 and 3 were structurally related to 1, previously reported antifungal antibiotic active against Penicillium chrysogenum, Colletorichum langenarium, Altenaria mali and Pyricularia oryzae [9]. In this paper, the taxonomy of the producing fungus and the fermentation, isolation, structure elucidation and biological properties of hydroxyfungerins are described. Furthermore, biological activities of 1 previously reported to have antifungal activity are also described.

Agrobacterium -Mediated Disruption of a Nonribosomal Peptide Synthetase Gene in the Invertebrate Pathogen Metarhizium anisopliae Reveals a Peptide Spore Factor

“…produce secondary metabolites in other chemical classes. These include the cytochalasins (1,24), helvolic acid (19), swainsonine (33,59), 12-hydroxyovalicin (47), viridoxins (29), fungerins (78), and metacytofilin (37). Although most of the known metabolites of Metarhizium exhibit biological activities in vitro against mammalian, insect, microbial, or plant cells, none has yet been demonstrated conclusively by genetic means to play an essential role in invertebrate disease.…”

Fusagerins A–F, New Alkaloids from the Fungus Fusarium sp.

“…Compounds 3 – 6 are closely related to fungerin ( 7 ) [ 14 ], all possessing the imidazole ring. To our knowledge, only three fungerin derivatives have been reported including visoltricin [ 50 ], and hydroxyfungerins A and B [ 51 ]. Compounds 3 – 6 differ from the above-mentioned natural products mainly on the identities of the side chains.…”

Yaequinolones, New Insecticidal Antibiotics Produced by Penicillium sp. FKI-2140

“…Antimicrobial activity against the following 14 microorganisms was measured by a paper disk method [1]. Bacteroides fragilis ATCC23745, Mycobacterium smegmatis ATCC607, Acholeplasma laidlawii PG8, Bacillus subtilis ATCC6633, Staphylococcus aureus FDA209P, Micrococcus luteus PCI1001, Escherichia coli NIHJJ-2 IFO12734, Pseudomonas aeruginosa IFO3080, Xanthomonas campestris pv.…”