Citrus natsudaidai

The specificity of pectinesterase is not so marked with respect to the alcohol moiety of the ester, as it hydrolyzes ethyl esters of D-galacturonans at a rate 6-16% that of de-esterification of the methyl esters.36 Citrus natsudaidai pectinesterase de-esterifies the ethyl esters of pectic acid at a rate l/5th to l/7th of that for the methyl esters the propyl and allyl esters are attacked at l/20th to l/80th of the rate.38 The tomato, citrus, alfalfa, and papaya pectinesterases do not hydrolyze the glycol and glycerol esters of pectin.39... 

More recently, Manabe (3A) purified PE from Citrus natsudaidai fruit by chromatography on a DEAE-cellulose column followed by Sephadex G-100 column adsorption of the active fraction. The final preparation was homogeneous as determined by disc electrophoresis and was A60 times as active as the original extract on a protein basis. 

Manabe, M. Purification and properties of Citrus natsudaidai pectinesterase. Agric. Biol. Chem., 1973, 37, 1487-1491. ... 

The flavonoid glycosides hesperidin (60) and naringin (61) (Fig. 11.25) from Citrus natsudaidai stimulated oviposition by Papilio protenor (Honda, 1986). Again, the compounds were inactive alone, but were active when combined with a more polar extract of the plant. 

Ohta, Y., and Y. Hirose Constituents of Cold-Pressed Peel Oil of Citrus natsudaidai Hayata. Agric. Biol. Chem. 30, 1196 (1966). 

Also obtained by alkaline degradation of Natsudaidain methyl ether (3,5,6,7,8,3, 4 -heptamethoxy-flavone) (SM) (m.p. 130-131°) [4970], (m.p. 128°) [4988] with potassium hydroxide in refluxing ethanol [4970], (75%) [4988]. SM was isolated from oil of the baric of bitter orange [4970] or was prepared by melhy-lation of Natsudaidain (3-hydroxy-5,6,7,8,3, 4 -hexamethoxyflavone) (m.p. 146°), itself isolated from the peel oil of Citrus natsudaidai HAYATA [4988]. 

Limonin and nomilin are two bitter limonoids present in citrus juices. Systematic organoleptic tests showed that the bitterness threshold is 6 ppm (5) for limonin, and 6 ppm (6) or 3 ppm (7) for nomilin. The bitterness due to limonin develops gradually in juices after extraction from certain varieties of oranges, grapefruit, lemon, Natsudaidai, mandarin and some other minor citrus such as Iyokan and Ponkan. This phenomenon is generally referred to as "delayed bitterness". 

Natsucitrine-1 1,6-diOH, 3,5-diOMe, 10-H Citrus hybrid Yalaha (C. paradisi x C. tangerina) [30], C. natsudaidai [19], C. sulcata [26]... 

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