Sterols from the Stems of Momordica charantia

Abstract

A new sterol, 5a,6a-epoxy-3b-hydroxy-(22E,24R)-ergosta-8,22-dien-7-one (1), together with eight known sterols, 5a,6a-epoxy-(22E,24R)-ergosta-8,22-diene-3b,7a-diol (2), 5a,6a-epoxy-(22E,24R)-ergosta-8,22-diene-3b,7b-diol (3), 5a,6a-epoxy-(22E,24R)-ergosta-8(14),22-diene-3b,7a-diol (4), 3b-hydroxy-(22E,24R)-ergosta-5,8,22-trien-7-one (5), ergosterol peroxide (6), clerosterol (7), decortinol (8), and decortinone (9), were isolated from the stems of Momordica charantia. Their structures were elucidated by mean of extensive spectroscopic methods, including 1 H, 13 C, 2D-NMR and HR-EI-MS, as well as comparison with the literature data. Compounds 1, 4, 5, 8, and 9 were not cytotoxic against the SK-Hep 1 cell line.

Halipanasterol, a New Sterol Isolated From the Marine Sponge Halichondria panicea

“…The very small J value of H-6 and H-7 ( J = 2.5 Hz) confirmed that these protons did not have the same axial orientation. The 13 C NMR data of C-5 (δ C 65.6), C-6 (δ C 62.6), and C-9 (δ C 134.5) of 1 were very similar to the corresponding data of 5 α ,6 α -epoxy-(22 E ,24 R )-ergosta-8,22-diene-3 β ,7 α -diol ( 1a ) (δ C 65.7, 62.6, and 134.4, respectively), 17 5 α ,6 α -epoxy-23-demethylgorgost-8-ene-3 β ,7 α -diol (δ C 65.6, 62.6, and 134.6, respectively), 21 and (24 R )-5 α ,6 α -epoxy-24-ethylcholest-8-ene-3 β ,7 α -diol (δ C 65.6, 62.5, and 134.5, respectively) 22 measured in the same solvent (CDCl 3 ). In addition, the chemical shifts of H-18 ( δ H 0.59) and H-19 ( δ H 1.14) of 1 were similar to the experimental, as well as the computational data for the structure 3 β ,7 α -dihydroxy-5 α ,6 α -epoxy-Δ 8 .…”

“…Detailed analysis of the 1 H and 13 C NMR data indicated that the structure of 1 was similar to those of 5α,6α-epoxy-(22E)-ergosta-8,22-diene-3β,7α-diol, except for the addition of a terminal double bond at C-25/C-26 (Table 1). [17][18][19][20] These suggestions were further confirmed by the HSQC, COSY, and HMBC spectra. The HMBC correlations from (δ C 62.6), and C-9 (δ C 134.5) of 1 were very similar to the corresponding data of 5α,6α-epoxy-(22E,24R)-ergosta-8,22diene-3β,7α-diol (1a) (δ C 65.7, 62.6, and 134.4, respectively), 17 5α,6α-epoxy-23-demethylgorgost-8-ene-3β,7α-diol (δ C 65.6, 62.6, and 134.6, respectively), 21 and (24R)-5α,6α-epoxy-24-ethylcholest-8-ene-3β,7α-diol (δ C 65.6, 62.5, and 134.5, respectively) 22 measured in the same solvent (CDCl 3 ).…”

“…Detailed analysis of the 1 H and 13 C NMR data indicated that the structure of 1 was similar to those of 5 α ,6 α -epoxy-(22 E )-ergosta-8,22-diene-3 β ,7 α -diol, except for the addition of a terminal double bond at C-25/C-26 (Table 1). 17–20 These suggestions were further confirmed by the HSQC, COSY, and HMBC spectra. The HMBC correlations from H 3 -19 ( δ H 1.14) to C-5 ( δ C 65.6), C-9 ( δ C 134.5) and C-10 ( δ C 38.0), from H-6 ( δ H 3.31) to C-7 ( δ C 67.1) and C-8 ( δ C 126.9), from H 3 -21 ( δ H 1.02) to C-17, C-20, C-22 ( δ C 135.7), from H 3 -28 ( δ H 1.08) to C-23 ( δ C 131.6), C-24 ( δ C 43.6), and C-25 ( δ C 149.8), and from H 3 -27 ( δ H 1.68) to C-24, C-25, and C-26 ( δ C 108.8) indicated 3 double bonds at C-8/C-9, C-22/C-23, and C-25/C-26, and the hydroxy group at C-7.…”

Polyaspers A and B, the First Ergosterol‐Polyether Adducts with Unprecedented 6/6/6/5/5/6/6/6/6 Nonacyclic Architecture from Aspergillus sp. TJ507

“…The structures of these compounds were established based on their NMR, HRESIMS, IR, ECD, and single‐crystal X‐ray diffraction data. Two known compounds were confirmed to be (3 β ,5 α ,6 α ,22 E )‐5,6‐epoxy‐3‐hydroxyergosta‐8,22‐dien‐7‐one ( 3 ), [ 32 ] and calvasterol B ( 4 ) [ 33 ] by comparing their NMR spectroscopic data as well as specific rotations with those reported in the literature.…”