Acer species

Bate-Smith, E. C., 1977, Astringent tannins of Acer species, Phytochem. 16 1421-1426. 

As evidenced by the dendrogram in Fig. 4.3, separation down to species level is superimposed by a high similarity within genera. Examples for a high chemical similarity within the same genus are the spectra obtained from two species of Prunus, Bird Cherry and Wild Cherry. They form a distinct group, as do also two Acer species, Norway Maple and Sycamore Maple (see Fig. 4.3). However, the pollen spectra from a third species of Acer, the Ash-leaf Maple (or Maple Ash), resemble those of oak and sycamore tree pollen rather than the other Acer species. The tree is native to North America, different from the other two Acer species, which are natives to Europe and Asia. 

Under the appropriate conditions, a sweet sap can be collected from most maple (Acer) species. In general, however, only the sap of sugar, black, and red maple is commonly used to make maple syrup. Where maple trees are found in abundance and weather conditions are appropriate, commercial maple production can occur. This ranges from Nova Scotia to Minnesota from east to west, and from southern Ontario and Quebec in the north to areas of West Virginia in the south (Heiligmann et ah, 2006). Boxelder is sometimes tapped in areas of Manitoba and the Pacific northwest. 

Trees. The major hypotheses that have been proposed to explain the patterns of decay development and its restriction in the wood (xylem) of living trees are outlined briefly. Furthermore, the current understanding of the biochemical and physiological events that contribute to the protection of pre-existing functional sapwood was reviewed with particular reference to the formation of reaction zones at the host-pathogen interface in Acer species, especially the European sycamore maple Acer pseudoplatanus). 

In a relatively small group of plants, more complex oxidative coupling occurs via pathway (c) to produce distinctive metabolites such as those found in some Geranium, Euphorbia, and Acer species (Fig. 12.10) (Haslam andLilley, 1986). Geraniin (26), widespread in plants, is one of these (Porter, 1989). 

Gramine (6) is found in several Acer species (Aceraceae, maples), barley (Hordeum vulgare), and a number of other plants. The mechanism of the side-chain modification which produces gramine from tiyptophan is not well understood. Tracer studies indicate fliat the indole unit is incorporated intact, but the origin of the second nitrogen atom is in doubt. The methylene carbon of gramine is the same as the methylene in the same position in tryptophan (Fig. 28.16). 

It is well known that, in the spring, the sap of the sugar maple Acer sac-charum) contains 3%-5% sucrose. Other Acer species generally contain less (1 % - 3.7%). In all Acer species, approximately 95% of the dry matter and 99.9% of the total sap sugar is sucrose (121, 175). For a discussion of sap extraction from Acer saccharum and measurement of soluble sugars, see Gregory and Hawkins... 

Bate-Smith E C 1978 Systematic aspects of the astringent tannins of Acer species. Phytochemistry 17 1945-1948... 

The distribution and mass budget of chemical species in the Oak Forest ecosystem have been studied in Hungary. The principal timber species is Quercurs petraea, accounting for 78% of the wood mass Quercus cents accounts for 22%. The shrubs are chiefly represented by Acer campestre and Cornus max, and the grass by the genera Carex, Dactylis, and Poa. 

In some species, however, e.g. ash, Fraxinus excelsior, cells of the traumatic axial parenchyma of the compartmentalization wall 4 may show no evidence of cell wall alterations, yet appear to act normally as a functional barrier to decay (Pearce, R.B., unpublished data). It is to be presumed that the spread of decay fungi is arrested either by chemical defences or by environmental constraints (cf. 26-28) in such species. Clearly, a contribution may be made by these defences in suberizing species also phytoalexin-like antifungal compounds have been detected in association with a suberized wall 4 barrier in Acer saccharinum (42). More work will be required to elucidate the long-term effectiveness of the various mechanisms maintaining the function of these barrier walls. 

Figure 3.4 Structures of the galactoglucomannan (a heteromannan) known to occur in the primary cell walls of several species of eudicotyledons and the glucuronoarabinoxylan (a heteroxylan) known to occur in the primary cell walls of sycamore (Acer pseudoplatanus). The structures of the heteromannans and heteroxylans in potato cell walls are unknown.

Patterns of polyphenol accumulation In leaves vary among the few temperate forest species which have been studied. Feeny s (42) classic study on oak leaves (Quercus robur) shows leaf tannin levels rising slowly until August, and then Increasing sharply. In the cases of sugar maple (Acer saccharum) and yellow birch (Betula lutea) (44), respectively. 

This is a north temperate family with some distribution in the mountains of the tropical zone. Trees are valued as ornamentals, as lumber, and, in northern North America at least, as the basis for the maple sugar industry (Acer saccharum). Of the species in the family, all but ten are assigned to the genus Acer. 

Fig. 8.1 Feeding preferences by free-ranging beavers Castor canadensis) for 3 species of northeastern deciduous trees and shrubs American beech (Fagus grandifolia), quaking aspen Populus tremuloides), striped maple (Acer pensylvanicum), witch hazel (Hamamelis virginiana), witch hobble (Viburnum lantanoides) and yellow birch (Betula alleghaniensis). The experiment was run over 10 days. Each morning the number of remaining sticks was counted. Only one of 10 beech sticks was taken after 10 days, while, at the other extreme, no sticks of aspen and striped maple remained after 4 and 5 days, respectively...

LESS SENSITIVE PLANTS Species of the genera Acer, Alnus, Populus, Quercus, Prunus, Rosa, Soknum, Zea, Vitis, Beta, Brassica, and species of the family of the Liliaceae 0.13 0.12 0.60 0.53... 

The maples are about 150 species of angiosperm trees and shrubs in the genus Acer, family Aceraceae. Most maples occur in temperate forests of the Northern Hemisphere. 

Open chain diarylheptanoids were isolated from Acer nicoense (Aceraceae), from Alnus and Betula species Betulaceae), from Alpinia, Curcuma and Zingiber species belonging to the family of gingers Zingiberaceae) and finally from certain Cenirolobium species (Leguminosae). Individual compounds will be classified according to the plant families in which they occur. 

Among leguminous Centrolobium species diarylheptanoids were first isolated from C. robustum in 1964 (5). It contains (-)-(R)-centrolobol (2), found later in several other plants too (Acer nicoense (Aceraceae) (6), Be tula pendula (Betulaceae) (24)) as well as two cyclic components, (3/ ,75)-centrolobin (67) and (3/ ,75)-de-0-methylcentrolobin (68) (47). First... 

The study of penetration by waterborne wood preservatives into wood was reported. Samples of three wood species, i.e. red maple Acer rubrum L.), ponderosa pine Finns ponderosa Dougl. ex Laws.) and aspen Populus tremuloides), containing different anatomical features, e.g. sapwood, heart-wood, early-wood, late-wood, and knots, were air-dried and pressure-treated with water. MRI provides a useful method for assessment of the penetrability of wood by water and consequently waterborne preservatives. 

---