Dancy Tangerine Research Articles

Two New Polymethoxylated Flavones, a Class of Compounds with Potential Anticancer Activity, Isolated from Cold Pressed Dancy Tangerine Peel Oil Solids

Ten polymethoxylated flavonoids were isolated and characterized from cold pressed tangerine oil solids; they are 5,6,7,3‘,4‘-pentamethoxyflavone (sinensetin) (I); 7-hydroxy-3,5,6,3‘,4‘-pentamethoxyflavone (II); 5-hydroxy-6,7,8,3‘,4‘-pentamethoxyflavone (III); 5,6,7,8,3‘,4‘-hexamethoxyflavone (nobiletin) (IV); 5,6,7,8,4‘-pentamethoxyflavone (tangeretin) (V); 5,7,8,4‘-tetramethoxyflavone (tetra-O-methylisoscutellarein) (VI); 7-hydroxy-3,5,6,8,3‘,4‘-hexamethoxyflavone (VII); 5,6,7,4‘-tetramethoxyflavone (tetra-O-methylisoscutellarein) (VIII); 3,5,6,7,8,3‘,4‘-heptamethoxyflavone (IX); and 5,7,8,3‘,4‘-pentamethoxyflavone (X). Structures of the compounds were elucidated on the basis of spectroscopic methods and chemical data. Compounds II and VII are novel natural products; compounds IV, V, and VIII have been reported with significant activity against various strains of carcinoma cells; and compounds I and IV decrease erythrocyte aggregation and sedimentation in vitro. A biological activity screen of other comp...

Constituents of Domestic Citrus Plants. Part XXVI. Studies on the Constituents of Yalaha. Structures of a New Acridone Alkaloid and Two New Coumarins.

A new acridone alkaloid, 1, 3, 5-trihydroxy-10-methylacridone (8), and two new coumarins, trans-clausarinol (9) and khelmarin-D (11), were isolated from the root of Yalaha [several hybrid seedlings resulting from a cross of Duncan grapefruit (Citrus paradisi MACF.)×Dancy tangerine (C. tangerina HORT. ex TANAKA)], and structures were determined on the basis of spectroscopic evidence. Seventy known coumarins, acridone alkaloids and miscellaneous compounds were also characterized.

Host-Specific Effects of Toxin from the Rough Lemon Pathotype of Alternaria alternata on Mitochondria

Host-specific toxin from the rough lemon (Citrus jambhiri Lush) pathotype of Alternaria alternata (ACR toxin) was tested for effects on mitochondria isolated from several citrus species. The toxin caused uncoupling of oxidative phosphorylation and changes in membrane potential in mitochondria from leaves of the susceptible host (rough lemon); the effects differed from those of carbonylcyanide-m-chlorophenylhydrazone, a typical protonophore. ACR toxin also inhibited malate oxidation, apparently because of lack of NAD(+) in the matrix. In contrast, the toxin had no effect on mitochondria from citrus species (Dancy tangerine and Emperor mandarin [Citrus reticulata Blanco], and grapefruit [Citrus paradisi Macf.]) that are not hosts of the fungus. The effects of the toxin on mitochondria from rough lemon are similar to the effects of a host-specific toxin from Helminthosporium maydis (HMT) on mitochondria from T-cytoplasm maize. Both ACR and HMT toxins are highly selective for the respective host plants. HMT toxin and methomyl had no effect (toxic or protective) on the activity of ACR toxin against mitochondria from rough lemon.

カンキツ類における果皮酸度の差異, 全酸, 遊離酸, および結合酸濃度間の関係およびそれら酸濃度の果肉汁酸濃度との関係

Total, free, and combined acidity of fruit rind were determined on 85 samples from 70 citrus species, to reveal their genetic variations.Free acidity of rind in most samples was below 17me/100g.Total acidity of rind in all samples lay between 4 and 23me/100g.The percentage of free acidity in total acidity was between 12 and 39% with two exceptions of 45% and 58%, and the average of all samples was 22%.Combined acidity in most samples was between 3 and 11me/100g. However, that of nine samples, namely Funadoko, Yuzu, Dancy tangerine, Jimikan, Rusk citrange, Mediterranean mandarin, and Miyauchi Iyo excceded 11me/100g, up to 23.2me/100g.There were high correlation coefficients among the three acidities within each group of samples. However, when all samples were observed as a whole, free acidity and combined acidity did not correlate significantly.Total, free, and combined acid content of rind per fruit were very high in Pummelo, which has the maximum weight of fruit and rind. Sudachi with the minimum weight of fruit and rind showed the lowest content of total, free, and combined acids. Acid content tended to be higher in species with heavier fruit weight and rind weight.However, the proportion of acid in rind to acid in whole fruit had no correlation to proportion of rind weight to whole fruit weight.The acid content of rind in relation to that of whole fruit was 0.8-47.5% for free acid, 2.3-48.7% for total acid, 18.0-72.5% for combined acid. Therefore, in order to get an accurate physiological understanding of the organic acids of citrus fruits, the total, free, and combined acid content of rind tissues should also be determined when estimating those of the whole fruit.

Genetic analysis of leaf isozymes in citrus.

Leaf isozymes of four enzymes in citrus were analyzed using polyacrylamide gel electrophoresis to demonstrate the phylogenic relationship of the cultivars. Two loci for the superoxide dismutase(SOD) (EC1.15.1.1), one locus for the peroxidase (EC 1.11.1.7) and polyphenol oxidase (EC1.10.3.2), respectively were examined. In addition to the two loci of glutamate oxal-acetate transaminase(GOT) (EC2.6.1.1), reported in the former study, a new locus was detected in the present report. These experiments suggest that the mandarin cultivars originated from three genetic sources ; Indian, Chinese, and Japanese ones. Most of the Chinese mandarins including 'Kinokuni' showed identical genotypes, while the 'Ponkan' and 'Dancy tangerine' differed from the Chinese cultivars in their genotypes at the Px locus, and they were assumed to have originated from India as suggested by T. Tanaka. On the other hand, the Japanese mandarins were considered to be genetically affected by the'Chinese mandarins. But some of the Japanese mandarins including 'Yatsushiro' and 'Koji' exhibited genetic effects from Tachibana, the wild type of the mandarin in J.apan. The genotypes of the sweet orange cultivars were homogeneous and similar to those 0L the Chinese mandarins. Sour orange was heterozygous at several loci, and was assumed to be a hybrid between mandarin and pummelo. Among the pummelo cultivars, some heterogeneity was detected at some loci.

A quantitative and structural comparison of Citrus pollen tube development in cross-compatible and self-incompatible gynoecia

Pollen tube development in Orlando tangelo (Citrus paradisi Macf. × C. reticulata Blanco.) was compared within and between cross-compatible pollinations of Orlando pollen on Dancy tangerine (C. reticulata Blanco.) stigmas and self-incompatible pollinations on Orlando tangelo stigmas. Orlando and Dancy gynoecia were morphologically similar but differed slightly in stigma, style, and ovary lengths. Orlando pollen tube development was studied 1, 3, 6, 9, and 12 days after both cross- and self-pollination to record the number of pollen tubes at each of five levels: stigma surface, upper style, lower style, ovary, and entrance into ovules. In the incompatible cross (self-pollinated Orlando), the stigma was the primary region of pollen tube arrest. In the compatible cross (Orlando pollen on Dancy), some pollen tubes penetrated ovules between 9 and 12 days after cross pollination; however, other pollen tubes were arrested in the stigma. Pollen tubes that successfully penetrated ovules in the compatible cross differed morphologically from pollen tubes arrested in both the compatible and incompatible situations. Successful compatible pollen tubes were straight with thin-walled tips and regularly spaced callose plugs behind the growing tips. Many pollen tube abnormalities associated with the self-incompatible pollination of Orlando were also present among arrested pollen tubes from the compatible cross.

Studies on host-selective toxins produced by a pathotype of Alternaria citri causing brown spot disease of mandarins.

Two host-selective pathotoxins, ACTG-toxins A and B, and four related but less active toxins, C, D, E, and F, were isolated from the culture broth of Alternaria citri, a fungus that produces brown spot disease of Dancy tangerine (Citrus reticulata) and other mandarin cultivars. The basic common structural features of these toxins were the presence of a six-membered group bonded, via a methylene group, to a five-membered ring having an alkenyl substituent (Fig. 1). For Toxins A, B, C and F, the six-membered ring had an enolizable β-diketo group. For Toxin C, the five-membered ring was a tetrahydrofuran group. For Toxins D and E, an additional dihydropyran ring was formed by dehydration between a tertiary hydroxyl on the cyclopentene ring and an enolic hydroxyl group on the cyclohexane ring, and also the presence of a terminal hydroxymethyl group on the alkenyl substituent, instead of the methyl groups in Toxins A, B and C. In Toxin F, the terminal group was a formyl.

The carotenoid pigments in the juice and flavedo of a mandarin hybrid (Citrus reticulata) cv michal during ripening

Abstract The carotenoid pigments ofthe mandarin hybrid ( Citrus reticulata ) cv Michal, in the juice and flavedo were characterized at three ripening stages, before, during and after colour break. During ripening the characteristic mandarin pattern was formed in the juice, which contained cryptoxanthin as the principal pigment. In the flavedo the chloroplast carotenoid pattern of the green fruit changed into the characteristic pattern of C. reticulata with a high level of citraurin which, together with cryptoxanthin, imparts an intensive reddish tint to the hybrid. The flavedo contained an unusual C 30 apocarotenoid, β-citraurinene (8′-apo-β-caroten-3-ol). The flavedo carotenoids of this accidental hybrid were compared with the carotenoids of the presumed parents Dancy tangerine and Clementine. The hybrid resembles more the second parent, from which it inherited the ability to biosynthesize a higher amount of citraurin as well as citraurinene. Citraurinene, considered a Citrus hybrid-specific pigment, was found for the first time in a Citrus variety. A possible biosynthetic pathway of the Citrus C 30 -apocarotenoids is proposed.

Pigment Changes in the Flavedo of Dancy Tangerine (Citrus reticulata) during Ripening

Summary Pigment changes in the flavedo of the Dancy tangerine were followed for an entire maturation period at two weeks intervals. The chlorophylls a and b gradually decreased at first but abruptly near the colour break and disappeared completely only in the mature fruit. The total carotenoid content decreased by half immediately at the beginning of the season and remained constant during a period of 14 weeks. Afterwards the level increased at an accelerated rate and reached a maximum value of about 300 µg/g. In the first period prior to the colour break the main carotenoid pattern was that found in photosynthetic tissue, containing: carotenes 20%, lutein 30%, violaxanthin 11% and neoxanthin 17%. A high level of α-carotene before the colour break was noteworthy. During maturation the chloroplast pigments decreased to minimal level of 1–2% except violaxanthin which rose to a level of 50%. Exactly at the colour break the biosynthesis of new pigments began, especially of the red β;-citraurin and the orange cryptoxanthin. Although their levels were not very high 8% and 14%, they are the pigments responsible for the orange-reddish colour of the tangerine. Phytofluene, ζ-carotene and the epoxides of cryptoxanthin were detectable at low levels in the last maturity stages. Some possible pathways of the C 30 -apocarotenals biosynthesis are discussed.

Effect of nutrient sprays on granulation and fruit quality of ‘Dancy tangerine’ mandarin

The efficacy of foliar spray of various macro- and micro-nutrients in different concentrations on granulation and fruit quality in ‘Dancy tangerine’ ( Citrus reticulata Blanco), a cultivar which suffers badly from granulation, was studied in the research orchard at the Punjab Agricultural University during 1974–1975 and 1975–1976. The combined spray of zinc sulphate 0.5% + copper sulphate 0.5% reduced the incidence of granulation to 45% from 78% in control during 1974–1975 (42% reduction over control). Potassium nitrate 1% (included in the second year of experimentation) gave the lowest granulation of 50% against 74% in control. The former treatment followed it closely. Low concentrations of boric acid (25 and 50 mg 1 −1) and calcium hydroxide 2% also markedly reduced the disorder. All these treatments improved the fruit quality and gave much more pulp, juice, T.S.S., sugars and ascorbic acid content than control, and they also markedly reduced peel, rag, total acidity and starch during both years. The application of nutrients is, therefore, considered to be a successful tool in reducing granulation in this cultivar of mandarin.

CITRUS PRODUCT COLOR ENHANCEMENT USING EXTRACTS OF PEEL OF DIFFERENT VARIETIES

SUMMARY— Colored fractions ware extracted and concentrated from peel of most commercial orange varieties and used to enhance the color of orange juice products. These included Pineapple, Hamlin, Parson Brown, Valencia, blood orange and Dancy tangerine. The relative yields of crude pigment per kg of peel were compared between he different varieties. The color extracts were analyzed for tristimulus yellowness (Y) and redness (RI factors. Crude pigment yields ranged from .34 g (Hamlin) to 1.29 g (Dancy tangerine) per kg of peel. R factors were highest for Dancy tangerine, followed by Pineapple orange and Valencia, and lowest for Hamlin. Y factors were highest for Dancy tangerine, followed by Valencia and Pineapple and lowest for Hamlin. Most color extracts were effective at a dilution of 113500 parts in improving the color of orange juice products.

The Occurrence of beta‐Citraurin and of beta‐Apo‐8′‐Carotenal in the Peels of California Tangerines and Oranges

SUMMARYbeta‐Citraurin was found to be a major component of the carotenoid mixtures of Clementine and Dancy tangerine peels, and a minor component in navel and Valencia orange peel carotenoids. beta‐Apo‐8′‐carotenal was present as a minor constituent in Clementine and Dancy tangerine peel carotenoids. A new carotenoid aldebyde, apo‐12′‐violaxanthal, was obtained from Clementine and Dancy tangerine peels.

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