臺灣博碩士論文加值系統

荔枝是為廣為人知的亞熱帶及熱帶水果，具高經濟價值，其所含諸多有益人體之成分，且野外荔枝樹下發現鮮少植物的生長，因此本研究分成兩部分，第一部分分離及純化荔枝葉中具保健功能潛力之天然化合物，第二部分則探討荔枝樹具植物相生相剋之潛力天然物。
第一部分以利用管柱色層分析法從荔枝葉中萃取分離、純化並鑑定天然物。共分出九種新的三烯生育醇 (tocotrienols)，分別為litchtocotrienol A~I，及四種已知化合物，4-hydroxybenzaldehye、procyanidin A2、(-)-epicatechin、4-hydroxy-3-methoxybisnbola-1,10-diene。Tocotrienols類衍生物已有文獻指出具抗癌和抗氧化活性，本研究所分離出的tocotrienols類是否具生物活性，則可進一步研究荔枝葉是否適合開發為抗癌保健食品。
第二部分以荔枝葉粉混土壤於盆栽實驗，以檢試對大花咸豐草之生長影響栽培之前二十三天對大花咸豐草之苗木具生長抑制效果，亦降低生物量，但第三十五天後卻喪失抑制效果。進一步將荔枝土壤經滅菌 (sterilization) 後將土壤置於培養盆中並加入二十分之一量的荔枝葉粉，再種植大花咸豐草幼苗。結果顯示，荔枝葉粉混以滅菌土壤後不具抑制效用，並對大花咸豐草幼苗和生物量具促進作用。然而無滅菌土壤則仍具抑制效用。此顯示土壤經滅菌後已失去土壤微生物，無法將荔枝葉的天然物分解成植物相生相剋作用物質，但無滅菌的土壤仍具微生物的作用，使荔枝葉的天然物釋放出來而相生相剋作用。進一步研究指出葉分解的化合物為4-hydroxy benzaldehye，其濃度在1 mM以上才具顯著抑制效果，上述結果知荔枝葉中相生相剋化合物與土壤中微生物可能具有直接相關，未來將進一步深入研究其機制。

Litchi (Litchi chinensis Sonn.) is a tropical and subtropical plant with high commercial value. In the field, there are relatively few understory species on the floor of litchi plants. Firstly, litchi leaves contain many natural product, and we have tried to isolate pure compounds in order to develop these compounds to be highly potential as a healthy food. Secondly, it is aiming to understand whether litchi plants may exhibit allelochemical potential.
In part one, methanolic extracts of litchi leaves were subjected to column chromatography. Nine new tocotrienols compounds (Litchitocotrienol A~I), and four known compounds (4-hydroxybenzaldehye, procyanidin A2, (-)-epicatechin, 4-hydroxy-3-methoxybisnbola-1,10-diene) were isolated and identified. These compounds exhibit anti-cancer and anti-oxidant activity. The above results of litchi leaves have the high potential to develop as anti-cancer healthy food.
In part two of pot experiment the lithci leaves exhibited inhibitory effect on seedling growth of Bidens pilosa during the first 23 days. But the inhibitory effect was disappeared 35 days after. However, the inhibitory effect of leaf powder against B. pilosa was decreased in the sterilized soil, indicating that the sterilized soil might lose the microbial involvement leading the litchi leaves were not be add to degrade the products into allelochemical agent. The alleolchemical, 4-hydroxybenzaldehye, isolated in the litchi leaves exhibited inhibitory effects on radicle growth of B. pilosa at 1 mM in the bioassay. It is concluded that allelochemicals in litchi leaves may involve in the interaction between plants and microbes. Futher studies should clarify the interaction between litchi leaves with soil microorganisms.

致謝 I
摘要 II
Abstract III
目錄 V
表目錄 VIII
圖目錄 IX
壹、 前言 1
一、 研究目的和動機 1
二、 生育醇 (tocopherol) 和三烯生育醇 (tocotrienol) 之文獻回顧 3
三、 荔枝介紹 7
(一)、 形態特徵 7
(二)、 歷史典故 7
(三)、 氣候環境 7
三、 荔枝藥用和化合物分析之文獻回顧 8
(一)、 中醫藥 8
(二)、 西醫 8
四、 植物相生相剋研究之概述 12
(一)、 揮發作用 (volatilization) 13
(二)、 淋溶作用 (leaching) 13
(三)、 分泌作用 (root exudation) 13
(四)、 植株殘體於土壤中的分解作用(decompostition of plant residues in soil) 14
貳、 材料與方法(一) 15
荔枝 (Litchi chinensis) 中化合物分離與純化 15
一、 實驗材料與儀器 15
二、 分離流程 15
參、 結果(一) 21
一、 荔枝甲醇萃取物之成分分離結果 21
(一)、 化合物1 (Litchtocotrienol A) 21
(二)、 化合物2 (Litchtocotrienol B) 34
(三)、 化合物3 (Litchtocotrienol C) 45
(四)、 化合物4 (Litchtocotrienol D) 56
(五)、 化合物5 (Litchtocotrienol E) 67
(六)、 化合物6 (Litchtocotrienol F) 78
(七)、 化合物7 (Litchtocotrienol G) 90
(八)、 化合物8 (Litchtocotrienol H) 102
(九)、 化合物9 (Litchtocotrienol I) 115
(十)、 化合物10 (4-hydroxybenzaldehyde) (10) 128
(十一)、 化合物11 (Procyanidin A2) (11) 130
(十二)、 化合物12 (4-hydroxy-3-methoxybisnbola-1,10-diene) (12) 132
(十三)、 化合物13 ((-)-epicatechin) (13) 134
肆、 討論 (一) 136
伍、 材料與方法(二) 138
荔枝葉之相生相剋研究 138
一、 實驗材料與儀器 138
二、 實驗方法 138
(一)、 荔枝葉粉和土壤對大花咸豐草生長抑制分析及土壤性質分析 138
(二)、 土壤pH值測定 139
(三)、 荔枝土壤消毒滅菌之抑制活性實驗 139
(四)、 生物活性測定 (Standard sponge bioassay) 140
(五)、 土壤性質分析 140
陸、 結果(二) 141
一、 荔枝樹土壤分析 141
二、 荔枝土壤生物分析 141
三、 化合物活性測定和種子生物分析 143
柒、 討論(二) 145
捌、 結論 148
玖、 參考文獻 149

李時珍 2009。 本草綱目。台灣，西北國際出版社

周昌弘 1990。 植物生態學。台北市，聯經出版社 第252-260頁。

張介賓 1959。景岳全書。上海市，上海科學技術出版社影印本

蘇玉和 2007。 荔枝之植物相生相剋潛能。屏東縣，屏東科技大學生物科技研究所碩士論文

顏立興 2010。 荔枝之植物相生相剋潛能。台中市，中國醫藥大學生態暨演化生物學研究所碩士論文

劉翰、馬志、翟煦、張素、王從蘊、吳復圭、王光祐、陳昭遇、安自良 1983。開寶本草。台北市，中國文化大學中華百科學書典藏版

歐陽脩、宋祁、范鎮、呂夏卿 2003。新唐書。北京 中華書局

An, M., J. E. Pratley, and T. Haig. 2001. Phytotoxicity of vulpia residues: IV. Dynamics of allelochemicals during decomposition of vulpia residues and their corresponding phytotoxicity. J. Chem. Ecol. 27:395-409.

Barbehenn, R. V., C. P. Jones, M. Karonen, and J. P. Salminen. 2006. Tannin composition affects the oxidative activities of tree leaves. J. Chem. Ecol.32:2235-51.

Barto, E. Kathryn, Monika Hilker, Frank Muller, Brian K. Mohney, Jeffrey D. Weidenhamer, and Matthias C. Rillig. 2011. The fungal fast lane: common mycorrhizal networks extend bioactive zones of allelochemicals in soils. PLoS ONE 6:27195.

Beyeler, M., and W. Heyser. 1997. The influence of mycorrhizal colonization on growth in the greenhouse and on catechin, epicatechin and procyanidin in roots of Fagus sylvatica L. Mycorrhiza 7:171-177.

Birt, Diane F., Suzanne H., and Weiqun, W. 2001. Dietary agents in cancer prevention: flavonoids and isoflavonoids. Pharmac. and Therape. 90:157-177.

Burdeos, G. C., K. Nakagawa, F. Kimura, and T. Miyazawa. 2012. Tocotrienol attenuates triglyceride accumulation in HepG2 cells and F344 rats. Lipids 47:471-81.

Chemda, D., Jiusheng, D., Avigdor, B., Ruth, E., Moshe, G., Shmuel, G. 2003. Identifying Lychee (Litchi chinensis Sonn.) cultivars and their genetic relationships using Intersimple Sequence Repeat (ISSR) markers. J. Amer. Soc. Hort. Sci 128:838-845.

Chou, C. H. 2006. Introduction to allelopathy.p.1-9 In Allelopathy, edited by M. J. Reigosa, N. Pedrol and L. Gonzalez (eds.): Springer Netherlands.

Chou, C. H., and Chiou, S. J. 1979. Autointoxication mechanism of Oryza sativa. J. Chem. Ecol. 5:839-859.

Chou, C. H., and Kuo, Y. L. 1986. Allelopathic research of subtropical vegetation in Taiwan. J. Chem. Ecol. 12:1431-1448.

Chou, C. H., and Lin H. J. 1976. Autointoxication mechanism of Oryza sativa I. Phytotoxic effects of decomposing rice residues in soil. J. Chem. Ecol. 2:353-367.

Chou, C. H., and Patrick, Z. A. 1976. Identification and phytotoxic activity of compounds produced during decomposition of corn and rye residues in soil. J. Chem. Ecol. 2:369-387.

Chou, C. H., and G. R. Waller (eds.). 1983. Allelochemicals and pheromones. insitut of botany academia sinica monograph series No. 5. Taipei, Taiwan. ROC.
Crozier, A., Jaganath, I. B., and Clifford, M. N. 2006. p. 1-24 Phenols, polyphenols and tannins: an overview. Blackwell: Oxford, UK.

Davis, E. F. 1928. The toxic principle of Juglans nigra as identified with synthetic juglone and its toxic effects on tomato and alfalfa plants. Am. J. Bot, 15:620.

de Mesquita, M. L., Araujo, R. M., Bezerra, D. P., Filho, R. B., de Paula, J. E., Silveira, E. R., Pessoa, C., de Moraes, M. O., Costa Lotufo, L. V., and Espindola, L. S. 2011. Cytotoxicity of δ-tocotrienols from Kielmeyera coriacea against cancer cell lines. Bioorg. Med. Chem. 19:8-8.

Deba, F., Tran, D. X., Masaaki, Y., and Shinkichi, T. 2008. Chemical composition and antioxidant, antibacterial and antifungal activities of the essential oils from Bidens pilosa Linn. var. Radiata. Food Control 19:346-352.

Duke, StephenO, AmyC Blair, FranckE Dayan, RobertD Johnson, KumudiniM Meepagala, Daniel Cook, and Joanna Bajsa. 2009. Is (−)-catechin a novel weapon of spotted knapweed (Centaurea stoebe). J. Chem. Ecol. 35:141-153.

Edrada, R. A., Peter, P., Victor Wray, Ludger Witte, and Leen van Ofwegen. 1998. Four new bioactive Lobane diterpenes of the soft coral Lobophytum pauciflorum from Mindoro, Philippines. J. Nat. Prod. 61:358-361.

Evans, H. M., Emerson, O. H., and Emerson, G. A. 1936. The isolation from wheat germ oil of an alcohol, ??-tocopherol, having the properties of vitamin E. Baltimore: J. Biol. Chem. 113:319-332

Fan, Q., Chen, S., Zhou, R., Xiang, X., Liao, W., and Shi, S. 2011. Genetic variation of wild litchi (Litchi chinensis Sonn. subsp. chinensis) revealed by microsatellites. Conserv. Genet. 12:753-760.

Fiorentino, A., Ricci, A., D''Abrosca, B., Golino, A., Izzo, A., Teresa, M. P., Piccolella, S., and Esposito, A. 2009. Kaempferol glycosides from Lobularia maritima and their potential role in plant interactions. Chem. Biodivers. 6:204-217.

Fiorentino, A., Mastellone, C., D’Abrosca, B., Pacifico, S., Scognamiglio, M., Cefarelli, G., Caputo, R., and Monaco, P. 2009. ??-Tocomonoenol: A new vitamin E from kiwi (Actinidia chinensis) fruits. Food chem. 115:187-192.

Guan, F., Li, G., Liu, A. B., Lee, M. J., Yang, Z., Chen, Y. K., Lin, Y., Shih W. and Yang, C. S. 2012. δ-and γ-Tocopherols, but not α-Tocopherol, Inhibit Colon Carcinogenesis in Azoxymethane-Treated F344 Rats. Cancer Prev. Res. 5:644-654.

Grondin, I., Smadja, J., Farines, M., and Soulier, J. 1995. Study of the triterpenic fraction of Litchi sinensis Sonn. and Euphoria longana Lam. seed oils. Oleagineux Corps Gras Lipides 2.: p. 229-235
Hejl, AngelA M., FrankA Einhellig, and JamesA Rasmussen. 1993. Effects of juglone on growth, photosynthesis, and respiration. J. Chem. Ecol.19:559-568.

Jaiswal, B. P., N. L. Sah, and U. S. Prasad. 1987. Regulation of colour break during litchi (Litchi chinensis Sonn.) ripening. J. Exp. Biol. 25:66-72.

Jang, K. H., Lee, B. H., Choi, B. W., Lee, H. S., and Shin, J. 2005. Chromenes from the Brown Alga Sargassum s iliquastrum. J. Nat. Prod. 68:716-723.

Jangra, Pankaj Kumar , Pramod, K. S., and Vipin, K. G. 2010. Medicinal Plants Having Anticancer Properties. J. Pharm. Res. 3:3093.

Janos, D. P., Michelle, S. S., Bruce, S., and Jonathan, H. C. 2001. Inoculation with arbuscular mycorrhizal fungi enhances growth of Litchi chinensis Sonn. trees after propagation by air-layering. Plant and Soil 233:85-94.

Ju, J., S. C. Picinich, Z. Yang, Y. Zhao, N. Suh, A. N. Kong, and C. S. Yang. 2010. Cancer-preventive activities of tocopherols and tocotrienols. Carcinogenesis 31:533-42.

Kendra, P. E., W. S. Montgomery, J. Niogret, J. E. Pena, J. L. Capinera, G. Brar, N. D. Epsky, and R. R. Heath. 2011. Attraction of the redbay ambrosia beetle, Xyleborus glabratus, to avocado, lychee, and essential oil lures. J. Chem. Ecol. 37:932-42.

Kenny, T. P., C. L. Keen, P. Jones, H. J. Kung, H. H. Schmitz, and M. E. Gershwin. 2004. Pentameric procyanidins isolated from Theobroma cacao seeds selectively downregulate ErbB2 in human aortic endothelial cells. Exp. Biol. Med. (Maywood) 229 (3):255-63.

Lankau, R. A. 2012. Coevolution between invasive and native plants driven by chemical competition and soil biota. Proc. Natl. Acad. Sci. U S A 109:11240-5.

Lee, H. S., and L. Wicker. 1991. Quantitative changes in anthocyanin pigments of lychee fruit during refrigerated storage. Food Chem. 40:263-270.

Lee, Jung Im, and Youngwan Seo. 2011. Chromanols from Sargassum siliquastrum and their antioxidant activity in HT 1080 cells. Chem.Pharm.Bull.59:757-761.

Li, W., H. Liang, M. W. Zhang, R. F. Zhang, Y. Y. Deng, Z. C. Wei, Y. Zhang, and X. J. Tang. 2012. Phenolic profiles and antioxidant activity of litchi (Litchi Chinensis Sonn.) fruit pericarp from different commercially available cultivars. Molecules 17:14954-67.

Liu, Liang, Bijun Xie, Shaoqian Cao, Erning Yang, Xiaoyun Xu, and Shanshan Guo. 2007. A-type procyanidins from Litchi chinensis pericarp with antioxidant activity. Food Chem. 105:1446-1451.

Lo, S. S., D. Frank., and W. H. Hitzig. 1973. "Vitamin E and haemolytic anaemia in premature infants. Arch. Dis. Child. 48:360-365.

Luk, S. U., Yap. W. N., Chiu Y. T., Lee Davy, T. W., Ma, S., Lee. T. K.W., Vasireddy, R. S., Wong, Y.C., Ching, Y. P., Nelson, C., Yap, Y. L., and Ling, M.T. 2011. Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population. Int. J. Cancer 128:2182-2191.

Luo, H., M. K. Daddysman, G. O. Rankin, B. H. Jiang, and Y. C. Chen. 2010. Kaempferol enhances cisplatin''s effect on ovarian cancer cells through promoting apoptosis caused by down regulation of cMyc. Cancer Cell Int. 10:16.

Mallik, A. U. 2003. Conifer regeneration problems in boreal and temperate forests with ericaceous understory: Role of disturbance, seedbed limitation, and keytsone species change. Crit. Rev. Plant Sci. 22:341-366.

Manu, K. A., Shanmugam, M. K., Ramachandran, L., Li, F., Fong, C. W., Kumar, A. P., Tan, P., and Sethi, G. 2012. First evidence that γ-tocotrienol inhibits the growth of human gastric cancer and chemosensitizes it to capecitabine in a xenograft mouse model through the modulation of NF-κB pathway. Clin. Cancer Res.18:2220-2229.

Mazza, G., and Velioglu, Y.S. 1992. Anthocyanin and other phenolic compounds in fruits of red-flesh apples. Food Chem. 43: 113-117.

Mazzini, F., Pescitelli, G., Di Bari, L., Netscher, T., and Salvadori, P. 2009. Circular dichroism of tocopherols versus tocotrienols. Chirality 21:35-43.

Mebius, L. J. 1960. A rapid method for the determination of organic carbon in soil. Anal. Chim. Acta 22:120-124.

Muller, C. H. 1966. The role of chemical inhition (allelopathy) in vegetational composition. Bull. Torrey Bot. Club 93:332-315

Muller, C. H. 1974. Allelopathy in the environmental complex, in Handbook of vegetation science part VI: vegetation and environment (eds B. R. Strain and W. D. Billings). Dr W. Junk BV Publisher: The Hague pp. 73–85.

Myohanen, Timo, Vaino Mantylahti, Kalevi Koivunen, and Rose Matilainen. 2002. Simultaneous determination of As, Cd, Cr and Pb in aqua regia digests of soils and sediments using electrothermal atomic absorption spectrometry and fast furnace programs. Spectrochimica Acta Part B: Atomic Spectroscopy 57:1681-1688.

Nair, MuraleedharanG, Whitenack, C., and Putnam, A. 1990. 2,2′-OXO-1, 1 ′-azobenzene A microbially transformed allelochemical from 2,3-Benzoxazolinone: I. J. Chem. Ecol. 16:353-364.

Numata, A., S. Kanbara, C. Takahashi, R. Fujiki, M. Yoneda, E. Fujita, and Y. Nabeshima. 1991. Cytotoxic activity of marine algae and a cytotoxic principle of the brown alga Sargassum tortile. Chem. Pharm. Bull. 39:2129-2131.

Pennock, J. F., F. W. Hemming, and Joan D. Kerr. 1964. A reassessment of tocopherol chemistry. Biochem. Biophys. Res. Commun. 17:542-548.

Politycka, B. and Adamska, D. 2003. Release of phenolic compounds from apple residues decomposing in soil and the influence of temperature on their degradation. Pol. J. Environ. Stud.12:p95.

Prasad, N. K., Yang, B., Zhao, M., Wang, B. S., Chen, F., and Jiang, Y. 2009. Effects of high-pressure treatment on the extraction yield, phenolic content and antioxidant activity of litchi (Litchi chinensis Sonn.) fruit pericarp. Int. J. Food Sci. Technol. 44:960-966.

Prasad, U.S., and O.P. Jha. 1978. Changes in pigmentation patterns during litchi ripening: flavonoid production. Plant Biochem. J. 5:44-49.

Qureshi, A. A., Mo, H., Packer, L., and Peterson, D. M. 2000. Isolation and identification of novel tocotrienols from rice bran with hypocholesterolemic, antioxidant, and antitumor properties. J. Agric. Food Chem.48: 3130-3140.

Rawat, M. S. M., G. Pant, D. Prasad, R. K. Joshi, and C. B. Pande. 1998. Plant growth inhibitors (Proanthocyanidins) from Prunus armeniaca - Role in Agriculture and Forestry. Biochem. Syst. Ecol. 26:13-23.

Reddy, P., and Urban, S. 2008. Linear and cyclic C18 terpenoids from the southern Australian marine brown alga Cystophora moniliformis. J. Nat. Prod. 71:1441-1446.

Rietveld, W.J. 1983. Allelopathic effects of juglone on germination and growth of several herbaceous and woody species. J. Chem. Ecol. 9:295-308.

Rodriguez, R., Moses, J. E., Adlington, R. M., and Baldwin, J. E.. 2005. A new and efficient method for o-quinone methide intermediate generation: application to the biomimetic synthesis of the benzopyran derived natural products (+/-)-lucidene and (+/-)-alboatrin. Org. Biomol. Chem. 3:3488-3495.

Sarni-Manchado, P., Le Roux, E., Le Guerneve, C., Lozano, Y., and Cheynier, V. 2000. Phenolic composition of litchi fruit pericarp. J. Agric. Food Chem. 48:5995-6002.

Sanchez-Moreno, C., Cao, G., Ou, B., Prior, R. 2003. Anthocyanin and proanthocyanidin content in selected white and red wines. Oxygen radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry. J. Agric. Food Chem.51:4889−4896

Sakane, W., Hara, N., Fujimoto, Y., Takaishi, Y., Acuna, R., Osorio, C., and Duque, C. 2005. Cupaniol, a new branched polyprenol, from Cupania latifolia. Chem. Pharm. Bull. 53:1037-1039.

Seo, Y., Park, K. E., and Nam, T. J. 2008. ChemInform abstract: isolation of a new chromene from the brown alga Sargassum thunbergii. ChemInform 39.

Shin, Y. G., and Yoon, S. H. 2009. New one-pot synthesis of 4-hydroxybenzaldehyde derivatives and picric acid from 4-hydroxy phenylglycine with HNO3/H2O. Notes 30:2819.

Souto, X. C., Gonzales, L., and Reigosa, M. J. 1994. Comparative analysis of allelopathic effects produced by four forestry species during decomposition process in their soils in Galicia (NW Spain). J. Chem. Ecol 20:3005-3015.

Tan, B. 2005. Appropriate spectrum vitamin E and new perspectives on desmethyl tocopherols and tocotrienols. JANA 8:35-42.

Tseng, M. H., Kuo Y. H., Chen, Y. M., and Chou, C. H. 2003. Allelopathic potential of Macaranga tanarius (L.) Muell. J. Chem Ecol. 29:1269-1286.

Vichnewski, W., Takahashi, A. M., Tucciturco Nasi, A. M., Rodrigues, D. C., Goncalves, G., Dias, D. A., Lopes, J. N., Rodrigues, D. C., Goedken, G., Gutierrez A. B. and Herz, W. 1989. Sesquiterpene lactones and other constituents from Eremanthus seidelii, E. Goyazensis and Vanillosmopsis erythropappa. Phytochemistry 28:1441-1451.

Wada, S. 2012. Cancer Preventive Effects of Vitamin E. Current Curr. Pharm. Biotechnol. 13:156-164.

Wang, X., Yuan, S., Wang, J., Lin, P., Liu, G., Lu, Y., Zhang, J., Wang, W., and Wei, Y. 2006. Anticancer activity of litchi fruit pericarp extract against human breast cancer in vitro and in vivo. Toxicol. Appl. Pharmacol. 215:168-178.

Xu, X., Xie, H., Hao, J., Jiang, Y., and Wei, X. 2011. Flavonoid glycosides from the seeds of Litchi chinensis. J. Agric. Food Chem. 59:1205-1209.

Yang, Z., Xiao, H., Jin, H., Koo, P. T., Tsang, D. J., and Yang, C. S. 2010. Synergistic actions of atorvastatin with γ-tocotrienol and celecoxib against human colon cancer HT29 and HCT116 cells. Int. J. Cancer 126:852-863.

Yao, L. H., Jiang, Y. M., Shi, J., TomAS-BarberAN, F. A., Datta, N., Singanusong, R., and Chen, S. S. 2004. Flavonoids in food and their health benefits. Plant Food Hum. Nutr. 59:113-122.

You, C. S., Sontag, T. J., Swanson, J. E., and Parker, R. S. 2005. Long-chain carboxychromanols are the major metabolites of tocopherols and tocotrienols in A549 lung epithelial cells but not HepG2 cells. J. Nutr. 135:227-32.

Yue-Ming, J., Zauberman, G., and Fuchs, Y. 1997. Partial purification and some properties of polyphenol oxidase extracted from litchi fruit pericarp. Postharvest Biol. Technol.10:221-228.

Zhao, Mouming, Bao Yang, Jinshui Wang, Baozhen Li, and Yueming Jiang. 2006. Identification of the major flavonoids from pericarp tissues of lychee fruit in relation to their antioxidant activities. Food Chem. 98:539-544.

Zhao, Mouming, Yang, B., Wang, J., Liu, Y., Yu, L., and Jiang, Y. 2007. Immunomodulatory and anticancer activities of flavonoids extracted from litchi (Litchi chinensis Sonn.) pericarp. Int. Immunopharmacol. 7:162-166.