Diplodia

The formation of optically active acyloins is also catalyzed by the yeast Candida Pareri if the bacteria Zymomonas mobilis and Zymomonas carlbergensis42 and the fungus Diplodia gossypina43. The latter microorganism produces (3/ ,66 )-6-hydroxy-7-oxo-8-norcitronellene from (/ )-citronellene by a reaction sequence that converts (7d)-citronellene to (/ )-4-methyl-5-butenal followed by addition of the acetyl moiety to the / e-face of the aldehyde. 

Diplodia. This disease has been reported from many areas of cacao production as caused by Botryodiplodia theobromae. It is associated with dieback of young branches and rotting of overripe pods. It is considered of little importance. 

In the first case the cutting undergoes a rot on its base, resulting in its death. In Ecuador and in Costa Rica isolations made of infected material have given Colletorichum, Fusarium, and Diplodia, as well as bacteria. 

Fruit Decay. Finally in the field of diseases are the decays of fruit in transit. Much of the Brazilian fruit is exported, giving a long period from harvest to utilization and in Argentina a slow rail transport plus the use of uninsulated metal cars adds to the problem. Stem-end rot (Diaporthe citri Wolfe and Diplodia natalen-sis Pole-Evans) plus blue and green molds (Penicillium italicum, Wehmer, and P. digitatum, Sacc.) are rampant, and while the Dowicide A (sodium orthophenyl phe-nate)-Hexamine (hexamethylenetetramine) treatment worked out in Florida is satisfactory, import difficulties stand in the way of obtaining needed materials. 

Recently, a patent described the use of Diplodia gossypina ATCC 10936 for the production of natural jasmonic acid [47]. With submerged cultures, up to 1.5 g L" jasmonic acid was obtained after 11 days of incubation the addition of 10-oxo-8-fra s-decenoic acid, a hormone stimulating mycelial growth, proved to be advantageous methyl jasmonate was obtained by autoclaving the... 

Fig. (3). Hydroxylation of myrcene by Diplodia gossypina (after[24]> and by Ganoderma applanatum and Pleurotus sp. (after [25])...

Another example of fungal bioconversion of linalool was described in literature the biotransformation by Diplodia gossypina ATCC 10936 [61]. A conversion scheme for the bioconversion of both (/ )-(-)- and (S)-(+)-linalool was proposed. 

The same group also studied the bioconversion of Z- and -nerolidol with three more fungal species Diplodia gossypina, Corynespora cassiicola and Gibberella cyanea [112]. It was found that all strains hydroxylated the substrates to their respective vicinal diols (glycols). The highest yield was obtained with the strain G. cyanea (79.5%) and the substrate -nerolidol. Also hydroxyketones were found in lower yields (0.5-5%) and in some cases traces of epoxides were produced. 

Abraham et al. [144-146] studied the biotransformation of caryophyllene (190) and humulene (196) by Diplodia gossypina (ATCC 10936) and two strains of Chaetomium cochliodes (DSM 63353 and ATCC 10195), Fig. (38) and Fig. (39). Sixty three products, including 49 that had never been described previously, were obtained and tested for their biological activity [147]. More recently, the bioconversion of (-)-caryophyllene by Chaetomium cochliodes IFO 30576 was also studied by another group [148]. The substrate was first epoxidized at the C-C double bond, producing (-)-caryophyllene-4,5-oxide (191), which was then hydroxylated at the ge/n-dimethyl group and C-7 position giving 193. 

Fig. (38). Main biotransformation products of caryophyllene by Diplodia gossypina and Chaetomium cochliodes (after [144,145])...

GE Brown, HS Lee. Interactions of ethylene with citrus stem-end rot caused by Diplodia natalensis. Phytopathology 83 1204-1208, 1993. 

A new toxic cytochalasin, chaetoglobosin K, isolated from Diplodia macro-spora, has the structure (24), according to the X-ray crystal-structure determination.24 Compared with chaetoglobosin A, metabolite K has additional methyl groups at positions 10 and 11 this raises the interesting possibility (among others) that propionic acid may be implicated in its biosynthesis. 

Introduction of a l/ -hydroxy group into 19-norsteroids has been carried out with Botryo-diplodia malorum. For example, the fermentation of 19-nortestosterone (3) gave, by direct crystallization of the crude reaction mixture, a single IjS-hydroxy-compound in about 30% yield79. 

Compound 117 is also a key intermediate in the synthesis of diplodiatoxin, a toxin produced by Diplodia maydis on maize and responsible for cattle disease [99]. The two chiral centers present in 117 are transferred in the target compound and induce all other chiralities of this bicyclic strucmre constructed via an intramolecular Diels-Alder reaction (Scheme 11.29). 

Ichibara, A, Kawagishi, H, Tokugawa, N, Sakamura, S, Stereoselective total synthesis and stereochemistry of diplodiatoxin, a mycotoxin from Diplodia maydis. Tetrahedron Lett, 27, 1347-1350, 1986. 

Most of these D-xylanase preparations, with the exception of that from Diplodia viticola, degraded D-xylan randomly, liberating xylose as well as oligosaccharides. The absence of D-xylose from the enzymic hydrolyzates from the latter source may be due to the fact that samples were only assayed in the early stages of hydrolysis (24 h). 

The diplodialides are a family of ten-membered ring macrocyclic lactones isolated from the pathogenic fungus Diplodia pinea. Structural studies by Wada in 1976 had shown these compounds to be quite similar to recifeiolide (1), with an additional oxygen functionality included p to the lactone carbonyl. Diplodialides A, B, C, and D (47-50) are the four most common members of this group. 

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