Malus pumila

Epoxy-18-oxo C18 Dicarboxylic acids Malus pumila young fruit ... 

The composition of cutin shows species specificity although cutin from most plants contains different types of mixtures of the C16 and C18 family of acids. Composition of cutin can vary with the anatomical location. For example, cutin preparations from fruit, leaf, stigma, and flower petal of Malus pumila contain 73%, 35%, 14%, and 12%, respectively, of hydroxy and hydroxy-epoxy C18 monomers [23]. In general, fast-growing plant organs have higher content of C16 family of monomers. 

Occurs in apples -Malus pumila and Pyrus communis... 

Proanthocyanidins Apple Malus pumila) Reflectron ( + ) Linear ( + ) IAA/Ag+ 308... 

Trimers Epicatechin-(4p 8)-epicatechin-(4fJ —> 6)-epicatechin Craetagus laevigata Malus pumila 164, 165 ... 

Holloway, P.J. (1973) Cutins of Malus pumila fruits and leaves. Phytochemistry 12,... 

Chemical Name Prunus species Synonyms Prunus armeniaca (Apricot) P. avium (sweet cherry) P. caroliniana (cherry laurel) P. cerasus (sour cherry) P. domestica (common plum) P. dulcis (almond) P. malus pumila (common apple and crab apple) P. persica (peach) P. serotina (wild cherry) P. virginiana (chokecherry) Chemical/Pharmaceutical/Other Class Cyano-genic glycosides... 

Intact cortical tissues of Malus pumila cv. Golden Delicious fruit were used throughout these experiments. Tissue fixation and determination of free e.g., nonmethylated uronic acid concentrations were described previously (18). 

The insoluble nature of suberin prevents its analysis by conventional NMR spectroscopy. The development of solid sample C-NMR spectroscopy with cross polarization/magic-angle spinning provides an opportunity to obtain spectra of the intact polymer. The NMR spectrum of the cutin polymer from the fruit of Malus pumila indicates, as expected, that the majority of carbons are methylenes (CH2, 20-30 ppm). The spectrum of suberin from 5. tuberosum showed the presence of a high proportion of aliphatic CH2 but also had a large amount of CHOH (60 to 80 ppm) carbon, probably from contaminating cell wall carbohydrates. This presumed carbohydrate material was still present in the residue left after LiAlH4 reduction, whereas the majority of aliphatic CH2 had been removed by this treatment (Fig. 6.4.8). This result shows that not much of the... 

Fig. 6.4.8. Cross-polarization/magic-angle spinning NMR spectra of cutin from the fruit peel of Malus pumila suberin from the bark of Pseudotsuga menziesiiy suberin from the periderm of the tuber of Solarium tuberosum and the residue left after L1A1H4 depolymerization of S. tuberosum suberin. (Spectra courtesy of Regional NMR Center, Fort Collins, Colorado.)...

Trihydroxyoctadecanoic acid was generated from 9,10-epoxy-18-hy-droxyoctadecanoic acid by a 3000-g particulate fraction obtained from the skin of the young fruit of Malus pumila (91). This enzyme activity did not require any cofactors and showed fairly stringent substrate specificity. It catalyzed the hydration of the m-epoxide to the /ireo-product and this stereospecificity is consistent with the natural occurrence of the /Areo-product in cutin. The trihydroxy Cig acid thus generated probably is the biosynthetic precursor of 9,10-dihy-droxyoctadecanedioic acid, which has been found in several suberin polymers (244). 

Croteau R, Kolattukudy P E 1975 Biosynthesis of hydroxy fatty acid polymers. Enzymatic hydration of 18-hydroxy-cis-9,10-epoxystearic acid to threo-9,10,18-trihydroxystearic acid by a particulate preparation from apple Malus pumila). Arch Biochem Biophys 170 73 - 81... 

Holloway P J 1982 Suberins of Malus pumila stem and root corks. Phytochemistry 21 2517-2522... 

Mazliak P 1963 La cire cuticulaire des pommes (Malus pumila L.). Ph.D. Thesis. Univ Paris, 115 pp... 

Aucuparin has been found to be a fungicidic phytoalexin of the loquat (Eriobotry japonica, Rosaceae) (119) and the compound also occurs in the sap-wood of the apple tree (Malus pumila, Rosaceae) when infected with the fungus that causes silver leaf disease (Chondrostereum purpureum) (70). The infected wood of the closely related pear tree (Pyrus communis, Rosaceae) (69) and the infected wood of Cotoneaster lactea (Rosaceae) (20) contain phytoalexins of the biogenetically related dibenzofuran type (a-, P-, and y-pyrufuran, and cotone-furan, 23 a-d). 

Kemp M S, Holloway P J, Burden R S 1985 3>5,19a-Dihydro-2-oxours-12-en-28-oic acid a pen-tacyclic triterpene induced in the wood of Malus pumila Mill, infected with Chondrostereum pur-pureum (Pers. ex Fr.) Pouzar, and a constituent of the cuticular wax of apple fruits. J Chem Res (S) 154-155 J Chem Res (M) 1848-1876... 

Haslam (57) noted earlier that two distinct and very common patterns may be distinguished in the procyanidins (i) those based on epicatechin-4 (T and M) units with also an epicatechin terminal (B) unit, and (ii) those based on epicatechin-4 (T and M) with a contrasting catechin terminal (B) unit. Those included in Type (i) were procyanidins from Malus pumila, Crataegus oxyacantha, Theobroma cacao, Cotoneaster sp., Cydonia oblonga, Prunus cerasus, and Aes-cuius hippocastanum. We have confirmed that this holds true for the procyanidin polymers as well, and others of this type include those from Chaenomeles chinen-sis, Persea americana, and Actinidia chinensis. 

The aroma of apples Malus pumila, syn. M. domestica, Rosaceae) consists of more than 300 different compounds, of which the most important components are C5 carboxylic acids, alcohols and esters. Important acids are 2-methylbutyric and 3-methylbutyric (isovaleric) acids, which are found in the fruits in a ratio... 

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