Fusicoccin. Part III. The structure of fusicoccin H

Abstract

J 9.5 Hz) (H-9) and a double doublet ( J 9.5 and 44 Hz) (H-8) were assigned to the allylic a-glycol unit on the basis of comparison with the corresponding fusicoccin derivative. The signals at 7 8.68 (3H, s), 9.02 (6H, d, J 6-5 Hz), and 9.1 (3H, d, J 6-5 Hz) account for one tertiaryiand three secondary methyl groups in the niolecule. The presence of the allylic a-glycol unit was confirmed by periodate oxidation of the aglycone (IVa), R2 0, C H2.OR' CH2.OH (rY) ( Y ) a; R1= R 2 = I1 b; R1 = 13, R2RL = CMe, c ; R1 = Me, R2R2 = CMe, giving the ap-unsaturated aldehyde (V), vmx.

Studies Towards the Total Synthesis of Di- and Sesterterpenes with Dicyclopenta[a,d]cyclooctane Skeletons. Three-component Approach to the A/B Rings Building Block

“…Fusicoccins A ( Scheme 2 ) and related diterpenoids [ 4 , 5 ] embrace the same dicyclopenta[a,d]- cyclooctane ring system, with the side chain shorter by one isoprene unit. The main representatives of this group have been isolated from the fungus Fusicoccum amygdali causing wilting disease of peach and almond trees.…”

“…The biosynthetic origins of ophiobolins were revealed some time ago [ 5 , 6 ]. Geranylfarnesyl pyrophosphate undergoes macrocyclisation as illustrated in Scheme 3 .…”

Fusicoccins P and Q, and 3-Epifusicoccins H and Q, New Polar Fusicoccins from Isolate Niigata 2-A of a Peach Fusicoccum Canker Fungus

“…Deisopentenyl-16-Odemethyl-FC J was prepared from 16-O-demethyl- Known FC H newly isolated from the fungus was identiˆed by its molecular formula, [a]D value, 4) and 1 H-NMR data.…”

“…Fusicoccins H(FC H) 4) and J(FC J) 5,6) (Fig. 1) have been isolated as important biosynthetic intermediates for FC A of FCs from the fungus by British and Italian workers.…”

An Enzyme Catalyzing O‐Prenylation of the Glucose Moiety of Fusicoccin A, a Diterpene Glucoside Produced by the Fungus Phomopsis amygdali

“…In vitro assay of PAPT: The assay mixture (100 mL) for PAPT contained FC P [40] or FC H (0.5 mm), [41] DMAPP (0.5 mm), Tris·HCl (50 mm, pH 7.5), and an appropriate amount of PAPT. This mixture was incubated at 30 8C for 2 h and the reaction was stopped by the addition of methanol (100 mL).…”