I. batatas

The jalapin-like chloroform-soluble material from the dried tubers of I. batatas was subjected to successive column chromatography over silica gel and HPLC to yield batatosides J-L (55-57) with the oligosaccharide core based on operculinic acid E. The lactonization site was placed at C-2 of the first rhamnose unit. Cinnamic acid was present as the esterifying residue at the C-2 position of the third rhamnose unit. These resin glycosides also contain esterifying residues composed of n-dodecanoic or (25)-methylbutyric acids at the C-2 or C-3 positions on the second rhamnose unit of the oligosaccharide core as well as n-decanoic or n-dodecanoic acids at C-4 on the third rhamnose (40). 

Native to tropical America, sweet potato (I. batatas) is a perennial morning glory vine that has been cultivated for over 5,000 years for its edible tubers in Mexico, Central and lowland South America, and the West Indies. Today, sweet potato is cultivated around the world, especially in developing countries (Plate 4). A decoction made from the leaves of this plant is used in folk remedies as a gargle to treat mouth and throat tumors, and poultices are prepared for inflammatory tumors (64). In Mexico, leaf decoctions are considered to be of cold nature , to reduce excessive body heat, contemporarily defined as such illnesses as diarrhea, dysentery, heart disease, stomach distress, fever, and gastrointestinal infection. In Chinese traditional medicine, the tubers have been used as a medicinal herb to eliminate secretion in perceived abnormal quantities of blood or other body fluids (79). 

This idea agrees well with a similar hypothesis presented for the solved structure of the catecholoxidase from I. batatas after superimposing the C-terminal sequence, which is not structurally resolved, on the known sttucture of the Octopus Here a leucine residue, Leu439 in... 

I. leptophylla I. carnea I. arborescens I. umbraticola I. batatas I. cairica... 

In case of I. batatas, the biosynthesis of chlorogenic acid proceeds via 1-0-caffeoyl-P-glucose in contrast to different solanaceous species e.g., Nicotiana taba-cum, which used caffeoyl-CoA for that purpose (Strack et al. 1987 and references therein). Furthermore, it was shown that chlorogenic acid acted as the acyl donor in the biosynthesis of isochlorogenic acid in the roots of this species (Kojima and Kondo 1985) which was also shown to produce neochlorogenic acid. 

There are cultivars of I. batatas which are only used for ornamental purposes (flowers, leaves) and not for tuber production This colour development is mostly caused by the free hydroxyl at C-5 of the anthocyanidin nucleus (Yoshida et al. 2003)... 

Simonin I from the tuber of I. batatas, ipomoeassins D/E from I. squamosa (Eig. 8.3), and leptophylhn A from the leaf/stem of I. leptophylla are the rare examples for a trani-cinnamoyl residue. 

Cmde polar extracts of sweet potato (/. batatas) root periderm tissue also inhibited germination of different species attempts to isolate the inhibiting principle failed (Peterson and Harrison 1991 and references therein). However, simonin IV, the major constituent from a certain variety of I. batatas, showed allelopathic potential including inhibition of radicle growth in a dose-dependent manner (Peieda-Miranda and Bah 2003 and references therein) though in a diminished extent compared to tricolorin A. 

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