Osladin

Colorless crystals

Fixed

202-204 ° C

Very low in water

Template: Infobox chemical / molecular formula search available

Osladin (of tschech. osladič " Polypody " to osladit " sweet ") is a steroid saponin, which in the rhizome of the ordinary Tüpfelfarns ( Polypodium vulgare) occurs.

The glycoside has a sweet taste, its sweetening power is about 500 times as large as that of sucrose. Hence the name Engelsüßwurzelstock dates for the rhizome of the fern. For toxicological reasons osladin is not suitable as a sweetener.

Structure and sweetening

The substance was first isolated in 1971 and elucidated its structure as a steroid saponin 1975. After the first total synthesis in 1993 by Yamada and Nishizawa, the product is not found to be sweet tasting. This led to the finding that the sweetening potency of the compound of the stereochemistry at the carbon atoms 22, 25 and 26 ( with tetrahydropyran Rhamnosylrest at the C- 26) depends, that had been neglected in the structure elucidation in 1975. Thus, the carbon atom is located at position 22 in the R, which in the S- and C -26 in the R- configuration, the C- 25.

The use of osladin as a sweetener preclude addition to the toxicity and low water solubility. While in first releases still called compared to cane sugar in 1971 and 1975, a 3,000 times sweeter, this value could be checked against the total synthesis and corrected 500 times the value.

Polypodosid A

Polypodosid A is closely related with osladin Sapoin that the rhizome of Polypodium glycyrrhiza ( licorice fern, Eng. Licorice far) occurs. It has at position C7 and C8 double bond equivalent, but otherwise osladin. Compared to a 6 % sucrose solution, it is about 600 times sweeter, but as osladin relatively insoluble in water. In addition, it has a slight licorice -like taste, and examples.

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