Structures et stereochimie des sesquiterpenes de Penicillium roqueforti pr toxine et eremofortines a, b, c, d, e

Chemical constituents of the mangrove-associated fungus Capnodium sp. SZ-F22. A new eremophilane sesquiterpene

“…Compounds 2-14 were identified as 1-hydroxyeremophil-7(11), 9(10)-di-en-8-one (2) (Sørensen et al 2007), warburgiadione (3) (Yamakawa et al 1979), ere-mofortine A (4) (Moreau et al 1980), 1b-hydroxypetasol (5) (Le et al 2013), 3b-hydroxy-7bH-eremophil-1(2),9(10),11(12)-trien-8-one (6) (Lin et al 2014), 1-ace-tyl-b-carboline (7) (Zhou et al 1998), regiolone (8) (Gulder et al 2012), 2-oxosk-atole (9) (Hoenicke et al 2002), tyrosol (10) (Wang et al 2009), 1-phenyl-1,2-et-hanediol (11) (Zhao et al 2006), α-acetylorcinol (14) (Nukina & Marumo 1977) by comparison of the NMR data with literature ( Figure 1).…”

Four New Chloro-Eremophilane Sesquiterpenes from an Antarctic Deep-Sea Derived Fungus, Penicillium sp. PR19N-1

“…Key 1 H and 13 C NMR resonances (Table 1, Table 2), especially for the shielded methyl groups at δ H 1.04 ( J = 7.0 Hz) and δ H 1.20, led us to consider an eremophilane-type sesquiterpene skeleton for 2 . The presence of an epoxide moiety with 13 C peaks at C-7 (δ C 61.8) and C-11 (δ C 67.3) was suggested by comparison of the 13 C NMR spectrum with those of 5a [9,10], and was confirmed by HMBC correlations (Figure 2) from H-13 to C-7, C-11 and C-12, from H 2 -6 to C-7, C-10, C-11 and C-14, and from H-12 to C-7, C-11 and C-13. According to the 1 H– 1 H COSY correlation between 12-OH and H 2 -12, the sole primary alcohol was also located at C-12.…”

“…Its extract exhibited brine shrimp lethality activity. Studies on the active constituents of this fungus led to the isolation of four new chlorinated eremophilane sesquiterpenes 1 – 4 , along with a known compound, eremofortine C ( 5 ) [9,10] (Figure 1). Herein, we describe their isolation, structure elucidation and in vitro cytotoxicity evaluation.…”

Identification of Intermediates in the Biosynthesis of PR Toxin by Penicillium roqueforti

“…Ther esults from these feeding experiments rather prove that C12 oxidation is independent of the double-bond migration. Compound 12 was demonstrated to be ap athway intermediate of PR toxin biosynthesis through feeding with (11,12, C 3 )-12.M any pathway intermediates have been suggested so far, [12,16,17] but now we have the first experimental evidence for 12 being at rue intermediate.T he strategy of labeling three neighboring carbons in 12 allowed very sensitive detection of incorporation through the observation of satellite signals resulting from 13 C, 13 C-coupling.T he phenomenon of 13 C, 13 Ccoupling in 13 CNMR spectroscopy can also be used to follow rearrangements of carbon skeletons,f or example,d uring terpene cyclizations, through the observation of rearrange-ment-induced 13 C, 13 C-couplings, [27,28] or for structure elucidation by 13 C, 13 C-COSY NMR. [28][29][30] Further applications of isotopic labelling techniques for investigating key steps of biosynthetic pathways are currently being developed in our laboratories.…”

“…The obtained data cleared some wrongly assigned chemical shifts in the structure elucidation of 3 (confusion of C13 with C15) [8] and were in agreement with two later reports. [11,23] Subsequently,t he biosynthesis of 3 was investigated by feeding with (2-13 C)-and (6-13 C)mevalonolactone (17). [18,24] Thei sotopically labeled compounds were fed to fungal cultures on hydrated rice medium, [15] and after two weeks of incubation, 3 was isolated with ay ield of 50 mg from 15 go f medium.…”