Steroids from the fungus Fomitopsis pinicola

Tirucallane triterpenes from the roots of Ozoroa insignis

“…The stereochemistry of the tetracyclic nucleus and orientation of the side chain were deduced from the following correlations observed in the NOESY spectrum: H-3 with 19-CH 3 and 29-CH 3 ; H-5 with 28-CH 3 ; H-17 with 30-CH 3 ; H-20 with 18-CH 3 ; and 19-CH 3 with 29-CH 3 . Nevertheless, when comparing the NMR spectral data of 1 with those reported for tetracyclic triterpenes (Knight, 1974;Ben Harref and Lavergne, 1985;Emmons et al, 1989;Gewal et al, 1990;Keller et al, 1996;Lin et al, 1997;Akihisa et al, 1998;Rö secke and Kö nig, 1999;Su et al, 2000;Wang et al, 2003;Usubillaga et al, 2004), it was not possible to confirm its structure as a tirucallane, euphane, or lanostane triterpenoid, since the corresponding carbon resonances are very similar, and occasionally, wrong assignments have been reported in literature (Emmons et al, 1989;Gewal et al, 1990). An essential aid that has been used for the discrimination of euphane (20R)/tirucallane (20S), is the NOE correlation of H-21 with H-16a,b in euphanes, and with H-12a in tirucallanes (Akihisa et al, 1996a(Akihisa et al, ,b, 1998Mohamad et al, 1999;Wang et al, 2003), but the oxidation of 21-CH 3 in compound 1 precluded the application of this tool.…”

Relaxing effects of Phellinus gilvus extract and purified ebricoic acid on rat aortic rings

“…The EtOAc extract was sequentially defatted with 150 ml of hexane and 150 ml of CH 2 Cl 2 to give the insoluble precipitate (279 mg). This precipitate, which showed a vasorelaxant effect on rat aorta, was run on HPLC using a reversed phase column (MeOH/H 2 O 95:5) to give eburicolic acid [5][6][7] (1:49 mg) and trametenolic acid B [8][9][10] (2:47 mg) (Fig. 1).…”

New polyhydroxylated steroids from the marine pulmonate Trimusculus peruvianus

“…Further considerations of 13 C NMR data showed that the C-17 chemical shift (δ ∼ 50 ppm) of compounds 1 and 2 is shielding by 5 ppm when compared with the corresponding C-17 in a reduced C-21 carbon (21-CH 3 ) of compounds 4a, 4b (Tables 1 and 2) and 5, Figure 7 (depicted as ring D and side-chain only). Also, in both 21-CH 2 OH and 21-CH 3 compounds 7a and 7b, respectively, isolated from a basidiomycete fungus 14 and with a known 20R configuration, similar shielding differences ∆δ ROH −δ RH ∼ 6 were also found. This may be rationalized as C-17, in compounds 1, 2, and 7a, are in a γ-gauche, 1,3 synperiplanar orientations, with the polar C-21-hydroxyl substituent, absorbing at significantly higher field than their reduced counterparts of compounds 5 and 7b.…”