Manna Douglas fir

A distinct feature of honeydew honey is the trisaccharide melezi-tose, which has been identified in the exudate manna of the Douglas fir the European larch, and the North American Jack or scrub pine. According to the late Professor C. S. Hudson, Turkestan manna contains 20-38% of melezitose, and Douglas-fir manna, 50% of melezitose. At one time, melezitose formed 20-30% of the total... 

Douglas fir, pentosan content, V, 271 Douglas fir manna, II, 11 DP. Definition as degree of polymerization, V, 106... 

In 1918 Miss Helene M. Boas, of the New York Botanical Garden, sent to the writer a sample of manna which had been collected by James A. Teit near Spence s Bridge, British Columbia, from Douglas fir trees (Pseudotsuga taxifolia Brit., syn. P. Douglasii Carr.). The dry, white, crystalline manna (42.5 g.), in which some small stems and needles of the tree (4 g.) were encrusted, was entirely soluble in water and it proved to consist principally of melezitose.17 The authors stated that if the manna can be obtained in large quantities, which appears to be the case, it will indeed furnish an excellent source for melezitose. However, there was found within a few months by the same workers an abundant... 

Mandelic acid, hexahydro-, optical rotation of, IV, 72 Manna, Alhagi, II, 4, 10 of ash tree, II, 3 III, 145 from Douglas fir, II, 11 larch, of Brian gon Persian, II, 6, 7 Turkestan, II, 5 Manna sugar. See D-Mannitol. 

Occurrence. The sugar, discovered by Berthelot in 1859, is a constituent of the sweet exudations of many plants such as the honeydew of limes and poplars, and the manna exuded from insect-produced wounds of the Douglas fir, Virginia pine, larch, etc. In dry seasons when the supply of flower nectar is insufficient, bees may collect these mannas or honeydews, and the honeys may contain considerable quantities of melezitose (151). When the quantity of the trisaccharide is great, crystallization of the honey may take place in the comb. Probably because of the resistance of the melezitose to hydrolysis by invertase, honeys which contain this sugar will not serve as food for bees. 

The rare trisaccharide melezitose [0-a-D-glucopyranosyl-(l- 3)-yff-D-fruc-to-furanosyl-(l- 2)-a-D-glucopyranose] occurs in the manna of Douglas-fir Pseudotsuga menziesii) (95), Virginia pine (Pinus virginiana), and Alhagi camelorum as a result of insect attack. 

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