104 



POLYHYDRIC ALCOHOLS 



[50-51. 



above i-erythritol, another modification, d-ery- 

 thritol : 



H OH 

 I I 

 HO . H 2 C . C . C . CH 2 . OH 



I I 

 H HO 



on reduction (Bertrand, Comp. Rend. 130, 

 1472). A partial synthesis of 1-erythritol start- 

 ing from 1-xylose has been effected by Maquenne 

 (Comp. Eend. 130, 1402). 



51. Mannitol ; 

 1 : 2 : 3 : 4 : 5 : 6 - Hexanehexol. 



H H HO HO 



HO. H 2 C- C C C-C CH 2 . OH 



I I I I 

 HOHO H H 



(Dextro-modification). 



NATURAL SOURCES. 



Mannitol is widely distributed through- 

 out the vegetable kingdom. Occurs in 

 ' manna/ the thickened sap of the 

 manna ash, Fraxinus ornus = Ornus 

 europce.a and 0. rotundifolia (Proust, 

 Ann. Chim. 57, 143 ; Tanret, Bull. Soc. 

 [3] 27, 947); in Australian manna from 

 Ulyoporum platycarpum (Fliickiger, Ch. 

 Zeit. 18, 1 85) ; in root of monkshood, 

 Aconitum wapellus (Smith, Jahresber. 

 1850, 535) ; in celery, Apium graveolens 

 (Pay en, Ann. 12, 60 ; Monteverde, Ann. 

 Agronom. 19, 444), parsley (Monte- 

 verde, he. tit.), and pomegranate root 

 (Boutron-Charlard and Guillemette, 

 Journ. Pharm. 21, 169) ; in leaves and 

 twigs of lilac, Syringa vulgaris (Roussin, 

 Jahresber. 1851, 550 ; Ludwig, Ibid. 

 1857, 503 : see also Monteverde, loc. 

 cit.}; in bark of Canella alba (Meyer 

 and Reiche, Ann. 47, 234 ; Petroz and 

 Robiquet, Journ. Pharm. 8, 198), and 

 of ash, Fraxinus excelsior (Rochleder 

 and Schwarz, Ann. 87, 186). 



Mannitol exists also in the sap of 

 Coniferse such as Pinus and Abies, &c. 

 (Kachler, Monats. 7, 410) ; in coffee 

 berries (Boussingault, Comp. Rend. 91, 

 639) and berries of EpJieclra distachya 

 (Meunier, Ann. Chim. [6] 22, 412) ; in 

 fruit of cherry laurel,Prw?/ laurocerasus 

 (Vincent and Delachanal, Comp. Rend. 

 114, 486) ; in olives (De Luca, Jahres- 

 ber. 1861, 740 ; 1862, 505 ; Bull. Soc. 



1863, 372) ; in pine-apple (Lindet, Ibid. 

 [2] 40, 65), and in the fruit of Cactus 

 opuntia (Berthelot, Ann. Chim. [3] 

 46, 66). The ' manna' of olives is an 

 exudation resulting from a bacterial 

 disease of the cambium layer and con- 

 tains 52 per cent, of mannitol (Trabut 

 and Schweinfurth, Comp. Rend. 132, 

 225 : see also Battandier, Journ. Pharm. 

 [6] 13, 1 77). 



Mannitol occurs in the cambium layer 

 of larch, Larix europcea, and other Coni- 

 ferse in the water dropwort, (Enanthe 

 crocata ; in Meum athamanticum Poly- 

 podium vulgare ; Scorzonera kispanica 

 Triticum repens; root-bark of Punica 

 granatum ; in leaves of privet, Ligustrum 

 vulgare ; in fruit of Laurus persea, and 

 in leaves of the cocoanut palm, Cocos 

 nucifera (Watts's Diet. Morley and Muir, 

 III, 189). 



Mannitol occurs also in the tubercles 

 of Cyclamen europceum (De Luca, Comp. 

 Rend. 47, 295 ; 87, 297 ; Bull. Soc. [2] 

 32, 417). The mannitol complex ap- 

 pears to be contained in cyclamin, the 

 glucoside occurring in this and other 

 species of Cyclamen and in Primulacese. 

 Mannitol has been found in certain 

 Scrophulariacese (272 species) of the 

 genera Rkinanthus and EupJirasia and in 

 some Orobancheacese, Oleacese, and Um- 

 belliferse (Monteverde, Ann. Agronom. 

 19, 444 ; Journ. Ch. Soc. 66, II, abst. 

 25) ; in leaves and bark of Genipa brasi- 

 liensis (Kwasnik, Ch. Zeit. 16, 109) ; 

 in leaves and bark of Basanacantha 

 spinosa,v&r.ferox (Griitzner and Pecholt, 

 Arch. Pharm. 233, i) ; in leaves of 

 Catha edulis (Beitler, Ibid. 239, 17); in 

 sap of the sea buckthorn, Hippophae 

 rhamnoides (Erdmann, Ber. 32, 3353). 



A true manna found on Andropogon 

 annulatus contains 58 per cent, manni- 

 tol (Baker and Smith, Journ. and Proc. 

 Roy. Soc. N. S. Wales, 30, 291). The 

 lichens Pfiyscia (Xanthoria} parietina and 

 Callopisma vitellinum contain mannitol 

 (Zopf, Ann. 30O, 354 ; for the former 

 Zopf quotes Lilienthal). 



Mannitol occurs in algse and fungi: 

 Laminaria saccharina (Stenhouse, Ann. 

 51, 349 ; Russula Integra (= Agaricus 

 integer] to the extent of 20 per cent. 

 (Thorner, Ber. 12, 1635); Lactarius 



