Isolates sweet potatoes

Most of the anthocyanins acylated with caffeic acid have this cinnamyl moiety linked to a glucosyl position 6, as in gooseberries, some grape cultivars, ° " ° black carrots, red cabbage,red radishes," and sweet potatoes. Some anthocyanins isolated from species of potatoes have a caffeyl group located at position 4 of the rhamnosyl unit of the rutinose disaccharide. " ... 

Among the hydroxycinnamic acids, anthocyanins acylated with sinapic acid are not widespread in foods they have been isolated only in black carrots " and red cabbages." Anthocyanins that are acylated with p-hydroxybenzoic acid were only found in black carrots " and sweet potatoes. This acyl group was located within the 6 position of a glucoside moiety. 

The literature on concentrated sweet potato protein is sparse. Amino acid patterns for sweet potato protein isolates have been reported by three groups (16, 45, 46). One report showed that when compared to the FAO standard (47), no amino acids were limiting. The other reports showed total sulfur amino acids and lysine to be limiting (Table III). The patterns indicate a nutritionally well balanced protein. The improvement in nutritional quality, when compared to amino acid patterns from whole sweet potato, is due to the fact that whole sweet potatoes contain substantial amounts of NPN, which consists mainly of nonessential amino acids. This effectively dilutes the EAA and lowers the amino acid score. 

Feeding studies with the rat as the test animal verified the high nutritional quality indicated by the amino acid pattern (45). Using isolates and concentrates prepared from Jewel and Centennial cultivars, PER values were equal to that of casein (milk protein) (Table IV). Examination of the amino acid patterns of sweet potato protein and casein revealed that both contained... 

Peterson JK, Harrison HE (1991) Isolation of Substance from Sweet Potato Ipomoea batatas) Periderm Tissue that Inhibits Seed Germination. J Chem Ecol 17 943... 

Purple acid phosphatase (PAP) or tartrate-resistant phosphatase is not thought to be a protein phosphatase but it has a very similar dimetallic active site structure to that found in protein phosphatases. PAPs have been identified in bacteria, plants, mammals, and fungi. The molecular weights (animal 35 kDa, plant 55 kDa) are different and they exhibit low sequence homology between kingdoms but the residues involved in coordination of the metal ions are invariant. " There has been considerable debate as to the identity of the metal ions in PAPs in vivo. Sweet potato, Ipomoea batatas, has been shown to possess two different PAP enzymes and the active site of one of them has been shown to contain one Fe and one Zn " " ion. Another report has established that the active site of a PAP from sweet potato contains one Fe " and one Mn +. The well-characterized red kidney bean enzyme and the soybean enzyme contain Fe " and Zn. Claims that PAP from sweet potato has 2Fe ions or 2Mn ions have been discussed elsewhere. One explanation is that these are different forms of the enzyme, another is that because the metal ions are labile and are rapidly incorporated into the active site, the enzyme contains a mixture of metal ions in vivo and the form isolated depends on the conditions of isolation. 

Torres et al. (2006) reported a novel microwave processing technique to produce biodegradable scaffolds for tissue engineering from different types of starch-based polymers. Potato, sweet potato, com starch, and non-isolated amaranth and quinoa starch were used along with water and glycerol as plasticizers to produce porous stmctures. Figure 16.1 shows the manufacturing procedure of microwaved starch scaffolds. 

The dihydrofurans ( )-ipomeamarone (482) and ( )-epiipomeamarone (483) were isolated from Myoporum desertii and exist in mould-damaged sweet potatoes as phytoalexins (73AJC375). The tetrahydrofuran derivatives (484) and (485) are potent antidepressants (74JOC1042). 

Some acid phosphatases from animals and plants are violet in color and contain iron (Chapter 16) and an Mn3+-containing acid phosphatase has been isolated from sweet potatoes.720 These enzymes have dimetal centers, often containing one Zn2+ and one Fe3+ with bridging carboxylate and hydroxide ions between the metals. Imidazole, tyrosinate, and carboxylate side chains hold the metals as in Fig. 16-20. A water molecule bound to the Fe3+ is thought to dissociate with a low pKa of 4.8 to give an Fe3+ OH complex. The hydroxyl ion can then attack the phospho groups, one... 

A number of purple acid phosphatases821 have been isolated from animal sources, including bovine spleen, rat bone and the enamel organ of rat molars. Other phosphatases may belong to this class but the identification is not yet certain. Purple acid phosphatase from the sweet potato, as noted in Section 62.1.3.6.1, contains manganese. 

Acyl silanes can display disparate behaviour when treated with carbon nucleophiles, even of related types5,61149. For example, when aroyl silanes were treated with a Wittig reagent, none of the expected alkenes was obtained, and the only reaction products isolated were silyl enol ether and triphenylphosphine (Scheme 73)182,183. When alkanoyl silanes were treated with Wittig reagents, however, only the normal olefinated vinyl silane products were isolated (Scheme 74)182-184 Under soluble lithium salt conditions, Z-vinyl silanes were produced with very high selectivities the reaction was used to prepare a pheromone component (50) of the sweet potato leaf folder moth (Scheme 75)183. 

In 1998, Krebs and co-authors reported the crystal structures of the catechol oxidase isolated from sweet potatoes (Ipomoea batatas) in three catalytic states the native met (CunCun) state (Figure 5.2a), the reduced deoxy (Cu Cu1) form, and the complex with the inhibitor phenylthiourea (Figure 5.2b) [19]. Typically for the type 3 active site, each copper ion is coordinated by three histidine residues from the protein backbone. In the native met state, the two copper ions are 2.9 A apart and, in addition to six histidine residues, a bridging solvent molecule, most likely a hydroxide anion, has been refined in close proximity to the two metal centers... 

Maltose (3-amylases are primarily found in plants and have been isolated from sweet potatoes,27 soybeans,28 barley29 and wheat.30 Maltose (3-amylases are also elaborated by bacteria, e.g. by Bacillus polymyxa,31 B. megaterium,32 B. cereus33 and Pseudomonas sp. BQ6.34 These (3-amylases all produce (3-maltose and a high molecular weight (3-limit dextrin. The limit dextrins result when the enzyme reaches an a-(l—>-6) branch linkage, which it cannot pass. Approximately half of an amylopectin molecule is converted to (3-maltose the remaining half is the (3-limit dextrin. 

The isolation of the first manganese-containing acid phosphatase was reported in 1971 from the juice of the sweet potato (Kokei No. 14) (67). The enzyme was unique in that it was distinctly purple, the color resulting from a broad absorption band with a maximum at 555 nm. The enzyme was determined to be 110 kDa, composed of two 55-kDa subunits. The purple enzyme was capable of hydrolyzing a variety of biologically relevant phosphates as well as inorganic pyrophosphate [Eq. (2)]. Emission spectroscopy revealed the presence of Mn (68). 

Similar Mn-containing enzymes were subsequently isolated from other plant sources spinach leaves (71), rice plant cultured cells (72), soybeans (73-75), and the tubers of the sweet potato Kintoki (76-81) (Table III). Sweet potatoes have recently been reported to possess two different acid phosphatases which were immunologically distinct but which have similar molecular weights and metal content (106). Interestingly, sulfhydryl reagents have been shown to inactivate the soybean enzyme (75). 

Two new toxic sesquiterpenoids, myodesmone (36) and isomyodesmone (37), have been isolated from the essential oils of certain Myoporum species. It has been suggested that these two compounds may be derived from myoporone (38), also found in some specimens of Myoporum deserti, by an in vivo aldolization-dehydration process via the ketol (39). In addition to ipomeamarone (40 R = H), it is reportedthat a new sesquiterpenoid, ipomeamaronol (40 R = OH) also occurs in diseased sweet potato root tissue. 

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