title: Four analogues of spiroleptosphol isolated from Leptosphaeria doliolum.
abstract: Spiroleptosphol B (2), spiroleptosphol C (3), norleptosphol C (4) and hydroleptosphol (5) were isolated from ascomycete Leptosphaeria doliolum. Detailed (1)H and (13)C NMR spectral analyses revealed these were structural analogues of spiroleptosphol (1) which we have recently isolated from the same fungi. Spiroleptosphol B (2) carried an unprecedent 5,3-dioxatricyclo[4.4.0.1(1.4)]undecane framework in place of the spirobicyclo ring system of 1. Spiroleptosphol C (3) was a 17-(R)-hydroxy derivative of 1. Norleptosphol C (4) was deduced to be the monocyclic structure biosynthetically resulted by decarboxylation from 3. Although 5 gave broaden (1)H NMR spectrum, it was gradually transformed to 2 which suggested being a hydrolysate of 1.
authors.affiliation: Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-Cho, Hirosaki, Aomori 036-8561, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Murakami
authors.forename: Taro
authors.initials: T
authors.lastname: Tsushima
authors.forename: Noboru
authors.initials: N
authors.lastname: Takada
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Tanaka
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nihei
authors.forename: Tomisato
authors.initials: T
authors.lastname: Miura
authors.forename: Masaru
authors.initials: M
authors.lastname: Hashimoto
mesh_terms: D001203:Ascomycota / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D013141:Spiro Compounds; C532933:spirolephtoshol