Manna larch

M. Berthelot, Ann. chim. phya., [3], 46, 66 (1856) [3], 06, 269 (1859) also Compt. rend., 47, 224 (1858). Berthelot gave the name melezitose (from le milhze, the larch tree) to the new sugar that he, following Bonastre, had crystallized from the larch manna of Briangon. 

Lactose, phenylosotriazole, III, 38 a-Lactose, acetochloro-, I, 40, 41 Lactyl chloride, acetyl-, III, 367 Laminarin, IV, 275, 282 Langenbeck s formulation of enzymatic glycoside hydrolysis, V, 58 Larch, e-galactan of, II, 249 Larch manna. See Manna. 

The occurrence of crystalline melezitose in a European honey was established conclusively in 1929 by Nottbohm and Lucius the source of this honey was the honeydew of linden trees one recalls that Maquenne isolated melezitose from honeydew of the linden in 1893. In their second article they report crystalline melezitose in a honey (Larchen-honig), the source of which was honeydew from larch trees of Austria, as reported to them by the entomologist Ludwig Amhart of Vienna. Two articles by Arnhart are of special importance regarding the caus of the occurrence of larch manna or honeydew. His observations convinced him that the saccharine material is to be attributed to the activity of plant lice of several kinds and he remarks that one can be deceived easily because some species are detectable on larch twigs only by a very careful examination. In some seasons of drought the dry, white manna... 

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... 

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. 

At least a dozen of these carbohydrate alcohols have been found widely distributed in plants, where they may represent a form of carbohydrate storage or a by-product in sugar metabolism. The most familiar are Erythrol, C4Hj(OH)4, found in algm and mosses D-Mannitol, CjHg(OH)g, the alcohol corresponding to mannose, found widely distributed in fungi and manna from tree sap, especially that of the larch Ji-Sorbilol, an isomer of D-Mannitol, found in the fruit of the mountain ash and most Rosaceoe. 

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