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A toxic substance produced by Nocardia otitidiscaviarum isolated from cutaneous nocardiosis
1Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan.
Abstract:
During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans.
Insights
Researchers discovered a potent toxin, HS-6, from Nocardia otitidiscaviarum. This macrocyclic compound exhibits significant in vitro and in vivo toxicity and antifungal activity.
Area of Science:
- Microbiology
- Toxicology
- Natural Products Chemistry
Background:
- Nocardia species are known producers of bioactive compounds.
- Cutaneous nocardiosis is an infection caused by Nocardia bacteria.
- The exploration of novel toxic substances from clinical isolates is crucial for drug discovery.
Purpose of the Study:
- To isolate and characterize a novel toxic substance from Nocardia otitidiscaviarum.
- To determine the chemical structure and toxicity profile of the isolated substance.
- To evaluate the potential antifungal activity of the compound.
Main Methods:
- Isolation and purification of the toxic substance HS-6 from Nocardia otitidiscaviarum.
- Determination of the chemical structure using spectroscopic methods.
- Assessment of in vitro and in vivo toxicity in mouse models and cell cultures.
- Evaluation of antifungal activity against pathogenic fungi.
Main Results:
- A novel toxic substance, HS-6, was isolated from Nocardia otitidiscaviarum.
- HS-6 is a 16-membered macrocyclic compound (C43H68O12).
- HS-6 demonstrated high toxicity with a mouse intraperitoneal LD50 of 1.25 mg/kg and an ED50 of 0.3 ng/ml for L1210 cells.
- The compound exhibited activity against Cryptococcus neoformans.
Conclusions:
- Nocardia otitidiscaviarum produces a potent macrocyclic toxin, HS-6.
- HS-6 possesses significant cytotoxic and antifungal properties.
- The structural elucidation of HS-6 opens avenues for further investigation into its therapeutic potential.