George M. Strunz

Enniatins fromFusarium avenaceum isolated from balsam fir foliage and their toxicity to spruce budworm larvae,Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae)

Material extracted from hyphae ofFusarium avenaceum, isolated from foliage of balsam fir,Abies balsamea, was toxic to spruce budworm larvae when incorporated into insect diet. The major insecticidal component of the toxic fraction was identified by chemical and spectroscopic methods as enniatin complex, rich in enniatin A/A1. Possible ecological implications of these observations are considered.

Synthesis of pungenin, a foliar constituent of some spruce species, and investigation of its efficacy as a feeding deterrent for spruce budworm [Choristoneura fumiferana (Clem.)].

Pungenin was synthesized from 3,4-dihydroxyacetophenone by a short sequence involving manipulation of protecting groups on the 3 and 4 hydroxyl functions. Bioassays indicated that the glucoside is a modest feeding deterrent for sixth-instar spruce budworm larvae, but it does not appear to retard the development of small larvae or lead to increased mortality.

Scytalidin: a new fungitoxic metabolite produced by a Scytalidium species

A new fungitoxic metabolite, designated scytalidin, was isolated from culture medium which had supported growth of Scytalidium sp., an imperfect fungus. The structure (3) of scytalidin (10-butyl-5,9,10,11-tetrahydro-10-hydroxy-4-pentyl-4H-cyclonona[1,2-c:5,6-c′]difuran-1,3,6,8-tetraone) was established on the basis of spectrometric and chemical investigations. The metabolite is related structurally and biosynthetically to the nonadrides.

Trichothecene mycotoxins produced byFusarium sporotrichioides daom 197255 and their effects on spruce budworm,Choristoneura fumiferana

Trichothecene mycotoxins were produced byFusarium sporotrichioides DAOM 197255 isolated from a spruce budworm cadaver. An extract from the culture filtrate containing these metabolites was toxic to budworm when ingested at concentrations as low as 10 ppm in diet, and survivors were predisposed to infection with a fungal entomopathogen. The possible role of these metabolites in the balsam fir-spruce budworm habitat is discussed.

Butenolides from citraconic anhydride and acetophenone: rearrangement to a 2,3-dihydro-3-furanone related to bullatenone

Two related butenolides, one having fungitoxic properties, were obtained from the reaction of acetophenone with citraconic anhydride in the presence of n-butyllithium. The butenolides rearranged to a 3(2H)-furanone related to bullatenone on acid treatment.

Hyalodendrin: a new fungitoxic epidithiodioxopiperazine produced by a Hyalodendron species

A new fungitoxic metabolite, designated hyalodendrin, isolated from a culture medium which had supported growth of Hyalodendron sp., an imperfect fungus, was identified as 3-benzyl-6-hydroxymethyl-1,4-dimethyl-3,6-epidithiopiperazine-2,5-dione on the basis of spectrometric and chemical investigations.

The action of hypochlorite on m-cresol. Part 2. Muconic acid derivatives

Two new crystalline products were isolated from the chlorination of m-cresol in cold alkaline solution. These products have been identified as E,Z-2-chloro-5-methyl muconic acid and 5Z-carboxymethylene-3-chloro-4-methyl-2(5H) furanone.

On the synthesis of cryptosporiopsin: stereochemistry of early intermediates

The relative configurations of two intermediates in the synthetic route to cryptosporiopsin are clarified through the structure of 3,5-dichloro-1,4-dihydroxy-2-methylcyclopent-2-ene-1-carboxylic acid methyl ester, which was determined by single crystal X-ray techniques. The crystal was monoclinic, space group P21/c, a = 7.352(1), b = 8.868 (3), c = 16.300(7) A; β = 96.49(2)°. The structure was solved by direct methods and refined to a final R of 0.057.