Theonella mirabilis

More recently, miraziridine A (113) was isolated from a marine sponge related to Theonella mirabilis and shown to inhibit the cysteine protease cathepsin B. It has been shown that the aziridine ring plays a key role in this biological activity and gives rise to irreversible inhibition of cathepsins B and L, presumably through... 

Nonribosomai peptide from sponge -Theonella mirabilis and Theonella swinhoei... 

Analysis of the extracts obtained from Papua New Guinea collections of Theonella mirabilis and Theonella swinhoei resulted in the isolation of four novel cyclic depsipeptides, papuamides A-D [52]. The structures of papuamide A (56) and B (57) were determined from a combination of spectroscopic analysis, chemical degradation and derivatization studies. 

Hydroxyethyl)dimethylsuIfoxonium chloride (1), the causative agent of Dogger Bank Itch which has previously been isolated from the marine bryozoan Alcyonidium gelatinosum [26], has now been isolated as a cytotoxic component of the marine sponge Theonella aff. mirabilis [506],... 

Nakao, Y.,Fujita,M.,Warabi,K.etfl/. (2000) Miraziridine A, a novel cysteine protease inhibitor from the marine sponge Theonella aff. mirabilis. Journal of the American Chemical Society, 122, 10462-10463. 

Miraziridine A 7 is a pentapeptide natural product isolated from the marine sponge Theonella aff. mirabilis in Japan in 2000 [3], It was also isolated 12 years later from the red sea sponge Theonella swinhoei [4], Miraziridine A inhibits cathepsin B with an IC50 value of 1.4 pg/ml. The sequencing of the amino acid residues and the absolute stereochemistry of each residue were achieved by a combination of Marfey analysis and nuclear magnetic resonance (NMR) data and resulted in the following sequence (2/ ,3J )-aziridine-2,3-dicarboxylic acid (Azd) (CO)/L-leucine (Leu) (NH), Leu (CO)/(35,45)-statine (Sta) (NH), Sta (CO)/(5)-a-aminobutyric acid... 

Miraziridine A (59) isolated from the marine sponge Theonella aff. mirabilis unifies within one molecule three structurally privileged elements (a) (2R,3R)-aziridine-2,3-dicarboxylic acid, (b) (35,45)-4-amino-3-hydroxy-6-methyUieptanoic acid (statine), and (c) (E)-(5)-4-amino-7-guanidino-hept-2-enoic acid (vinylogous arginine). 

Fusetani, N., Fujita, M., Nakao, Y, and Matsunaga. S. (1999a) Tokaramide A, a new cathepsin B inhibitor from the marine sponge Theonella aff, mirabilis. Biotg, Med. Chem. Lett., 9, 3397-3402. 

---