Punctaporonins N–S, New Caryophyllene Sesquiterpenoids from Cytospora sp.

Abstract

Six new caryophyllene sesquiterpenoids, punctaporonins N–S (1–6), and three known ones, 6-hydroxypunctaporonins B (7), A (8), and E (9), have been isolated from solid cultures of Cytospora sp. The structures of 1–6 were elucidated primarily by NMR spectroscopy. The absolute configuration of 1 was assigned by X-ray crystallographic analysis of its S-MTPA ester. Compounds 2, 5, and 6 showed modest cytotoxicity against HeLa cells.

Identification of Insect-Deterrent Metabolites from Acremonium masseei strain CICY026, a Saprophytic Fungus from a Sinkhole in Yucatán

“…In addition, the double of doublet of doublets at 2.04 ppm, with coupling constants of 10. and H-5/H-8, respectively. These values match the trans arrangement revealed for coupling constants, suggesting a trans-fused bicyclic molecule as found in the structure of punctaporonin and analog metabolites [29][30][31].…”

“…The values of the dihedral angles were 178.5°, 171.7°, and 169.4° for H-5/H-4, H-5/H-6, and H-5/H-8, respectively. These values match the trans arrangement revealed for coupling constants, suggesting a trans-fused bicyclic molecule as found in the structure of punctaporonin and analog metabolites [29][30][31]. The relative configuration of 1 was deduced using a NOESY analysis, which displayed key spatial couplings between H-2 with H-4b, H-6, H-7b, and H-8, which led us to locate these protons on the same face of the structure.…”

A Review of Fungal Protoilludane Sesquiterpenoid Natural Products

“…Both 152 and 153 were investigated for their antimicrobial activities against B. subtilis ATCC6051, S. aureus ATCC29213, E. coli ATCC25922 and C. albicans ATCC14053 and 153 was found to exhibit weak activity against the two Gram-positive bacterial strains in disk diffusion assays at a loading of 100 µg per disk [ 105 ]. In addition, both compounds 152 and 153 were found to be non-cytotoxic against HeLa cells with IC 50 >100 µM [ 106 ].…”

“…A further five protoilludanes, punctaporonins O–S ( 161 – 165 ), were isolated from the plant pathogen, Cytospora sp. ( Figure 25 ) [ 106 ]. Determination of the absolute configuration of punctaporonin O ( 161 ) was achieved by comparison of optical rotations with 6-hydroxypunctaporonin A ( 152 ) which led to assignment of the remaining natural products by consideration of shared biogenetic origins.…”

“…Determination of the absolute configuration of punctaporonin O ( 161 ) was achieved by comparison of optical rotations with 6-hydroxypunctaporonin A ( 152 ) which led to assignment of the remaining natural products by consideration of shared biogenetic origins. The cytotoxicity of puctaporonins O–S ( 161 – 165 ) were investigated against HeLa cells, where 161 , 164 and 165 exhibited moderate cytotoxicity (IC 50 16.6, 10.4 and 47.4 µM, respectively), while 162 and 163 were non-cytotoxic (IC 50 >100 µM) [ 106 ].…”