Stachybocins, Novel Endothelin Receptor Antagonists, Produced by Stachybotrys sp. M6222. II. Structure Determination of Stachybocins A, B and C.

Marilines A–C: Novel Phthalimidines from the Sponge‐Derived Fungus Stachylidium sp.

“…The structurally most simple phthalimidines possess an unsubstituted nitrogen atom as found in mariline C ( 3 ), namely 6‐hydroxy‐4‐methoxy‐5‐methylphthalimidine (cichorine),2, 3 zinnimidine,4 duricaulic acid,29 memnobotrin A and the related stachybotrylactam30 and the more complex xylactam 31. Reported N‐substituted phthalimidines include compounds with a phenylethyl,13, 32 ethyl‐1‐ol,6, 7 or a carbonic acid9, 12 moiety attached. Of these, examples of fungal phthalimidines structurally related to marilines A 1 and A 2 ( 1 a and 1 b ) include hericenone B and stachybotrin C,13, 32 both with a phenylethyl moiety connected to the nitrogen atom.…”

“…and are reported to possess endothelin receptor antagonistic effects. The latter also has HIV‐1 protease inhibitory properties 9. 10 The antifungal pestalachlorides isolated from Pestalotopsis adusta ,11 the aldose reductase inhibitors salfredins from Crucibulum sp.,12 and the cytotoxic hericenone B isolated from Hericium erinaceum 13 additionally demonstrate the broad spectrum of bioactivity found for fungal‐derived phthalimidine‐like structures.…”

Spirocyclic Drimanes from the Marine Fungus Stachybotrys sp. Strain MF347

“…Therefore, the structure of this compound was elucidated as a new spirocyclic drimane coupled by two drimane fragment building blocks and given the trivial name stachyin B. Most dimeric spirodihydrobenzofuranlactams isolated from natural resources are those whose the monomers are connected by a N and N connecting unit, such as N–C(OOH)CH 2 CH 2 CH 2 CH 2 –N in compounds 11 and 12 [16]. The structure of 2 is the first example of spirocyclic drimane coupled by a spirodihydrobenzofuranlactam unit and a spirodihydroisobenzofuran unit, and the connecting position being an N–C instead of an N and N connecting unit.…”

“…Furthermore, six known spirocyclic drimanes, chartarlactam O [23], chartarlactam K [23], F1839A ( 7 ) [21], stachybotrylactam ( 8 ) [3], stachybotramide ( 9 ) [3] and 2α-acetoxystachybotrylactam acetate ( 10 ) [1], and two known spirocyclic drimanes featured by two sesquiterpene-spirobenzofuran structural units connected by a lysine residue, stachybocin B ( 11 ) [16] and stachybocin A ( 12 ) [16], and a known sesquiterpene, ilicicolin B ( 13 ) [24] were identified by comparison of their spectroscopic data with those reported in the literature [3,16,21,23,24]. …”

“…However, dialdehyde derivatives were rarely isolated from the genus Stachybotrys , since dialdehydes are relatively unstable and often undergo conversion to stachybotrylactones [14]. Although many spirocyclic drimanes were reported to be toxins, they showed various biological effects, such as immunosuppressive activity [13], endothelin receptor antagonistic activity [15,16], and tyrosine kinase inhibitory activity [17]. …”