Oximes sponge

In the seven-step stereoselective total synthesis of ptilocaulin 44 [21 ], a potent antileukemic and antimicrobial agent isolated [22] from marine sponges, the oxime 36 was treated with NaOCl providing the tricyclic isoxazoline 38 in 89% yield without isolation of the nitrile oxide intermediate 37 (Scheme 5) [23]. Isoxazoline 38 was obtained as a mixture of four diastereomers and their ratio was... 

Psammaplysins appear to be biogenetically derived from dibromoty-rosine through an intermediate containing an arene oxide and oxime (329). Ianthelline (396) was isolated from the sponge Ianthella ardis collected in the Bahamas and possessed antimicrobial activity (330). 

Aerothionin, a tetrabromo derivative, has been isolated from sponges Aplysina aerophoba and Verongia thiona the proposed structure is 24 (46). The oxime 25 was formed by treatment of aerothionin with dilute alkali. The relative positions of the aromatic substituents in 25 were established by cleavage in hot 6 N HC1 to give 26 and a lactone subsequently converted by methylation to 27. The tetramethyl derivative of 25 was hydrolyzed to form... 

The isolation of psammaplin derivatives from the sponge PsammaplysiUa purpurea, in particular the only nonhalogenated analog, prepsammaplin A (105), allowed Jimenez and Crews to propose a biogenesis for this family of amino acid derivatives in which psammaplin A is formed by the linear combination of two bromotyrosine oxime derivatives and two rearranged cysteines [102]. 

Aerothionin (809), homoaerothionin (810) and aerophobin-1 (811), metabolites of sponges such as Aplysia flstularis and Veronia thionia, have a unique spiroisoxazohne framework. These metabolites must be biosynthesized in nature from a common phenylpyruvate oxime intermediate. 

The monomeric structural unit of the 3-alkylpiperidine alkaloids is readily apparent in a number of simple 3-alkylpyridines isolated from marine sponges. In all known examples, the 3-alkyl component of the monomeric unit is attached to a primary amine, methyl amine, methoxy amine, methoxy methyl amine, imine oxide or oxime methyl ether functionality at the distal terminus. 

As described above (see Section VILA), soluble ChE and oxime together detoxify OP compounds. These features were combined to developed a sponge product composed of ChE (FBS-AChE and EqBChE), organophosphate hydrolase (rabbit or bacterial OPH), oxime (2-PAM or HI-6), and polyurethane foam combinations for the removal and decontamination of OP compounds from medically important biological surfaces such as skin. This is an important extension of the bioscavenger approach to external decontamination and protection against organophosphate toxicity, since currently... 

Open chain or macrocyclic oximes (more than 30 described) from the south Pacific sponge lanihella basta. They are formed from 4 bromotyrosine units by single or double oxidative phenol coupling. B. act on the calcium channels of skeletal muscle. An example is B.-4 [Cj4H25BrjN40g, Mr 1017.11, yellow needles, mp. 250°C (decomp.)]. 

A rather different phenolic oxidation, that of the oxime (154) with thallium(III) trifluroacetate to give the isoxazole (155), followed by zinc borohydride reduction, has been used to give (156) which is a versatile intermediate for the synthesis of the sponge metabolites ( )-aerothionin (157a), ( )-homoaerothionin (157b), and ( )-aerophobin-1 (158). ... 

To increase the OP/enz5mie stoichiometry, polyurethane-immobilized enzymes were combined with oximes (enzyme reactivators such as HI-6 Peter et al., 2007) so that the catalytic activity of OP-inhibited AChE (or BChE) is rapidly and continuously restored before irreversible aging of the enzyme-OP complex can occur. Thus, the OP is continuously detoxified. A reusable immobilized-enzyme sponge of ChEs and oximes for OP decontamination is the envisioned product. Next, it... 

Calcul, L, Inman, W.D., Morris, A.A., Tenney K., Ratnam, J., McKerrow, J.H., Valeriote, F.A., and Crews, P. (2010b) Additiorial insights on the bastadins Isolation of analogues from the sponge lanthella cf reticulata and exploration of the oxime configurations. /. Nat. Prod., 73, 365-372... 

Kovganko, N.B. and Chernov, Y.G. (2000) Novel synthesis of (24R,6 )-24-ethylcholest-6-hydroxyimino-4-en-3-one, a steroidal oxime from Cinachyrella spp. sponges. Chem. Nat. Compd. (Eng. Trans.), 36,189-191. 

Alkaloid 178 was isolated from P. purpurea collected in the Seychelles by Faulkner s group (82). Since it is the presumed biogenetic precursor of 14-debromo-araplysillin-I (101), the name 14-debromoprearaplysiUin I was given. The isolation of spiroisoxazoline 101 and the oxime 178 from the same sponge was the first reported instance in which a spiroisoxazoline has been isolated together with its proposed precursor. 

Fusetani et al. reported nine new bromotyrosine-derived metabolites, purpur-amines A-I (179-187), from P. purpurea (121). The carboxylic acid oxime units present in the bromotyrosine-derived metabolites were exclusively derived from bromotyrosines, while the oxime function in purpuramines A-I (179-183) is part of a phenylalanine moiety, which is a new variant among verongid metabolites. Phenylpyruvic acid oxime (188), which is a building block for 179-183, was also isolated from the sponge. 

Purpuramines A-I (179-187) exhibited antibacterial activity against Staphylococcus aureus, but phenylpymvic acid oxime (188) was not active. Purpuramine J (189) was isolated from the Fijian sponge Psammaplysilla (Druinella) sp., along with purpuramine I (187), aplysamine 2 (172), and eight other bromotyrosine derivatives (86). Purpuramine J (189) is the first bromotyrosine derivative containing an A-oxide functionality, which is considered rare in marine natural products. 

The genus Verongia continues to yield tyrosine-derived bromo-compounds. The latest addition to this group is (227) from V. aurea 188). It represents a major departure from the previously reported compounds listed in Chart 1 in having a rearranged dibromotyrosine skeleton. The hypothesis of an oxime precursor of aerothionin (7), homoaerothionin (8) and the nitrile aeroplysinin-1 (4 and 5) (see 15 and 16) has received support by isolation of the oximinopyruvic acid (228) from a marine sponge Hymeniacidon sanguinea 189). 

Cimino, G., S. De Stefano, and L. Minale Occurrence of 4-hydroxyphenylpyruvic acid oxime in the marine sponge Hymeniacidon sanguinea. Experientia 31, 756 (1975). Cimino, G., S. De Stefano, A. Guerriero, and L. Minale Furanosesquiterpenoids in sponges-I Pallescensin-1, -2, and -3 from Disidea pallescens. Tetrahedron Letters 1975, 1417. 

---