HIV infection in humans is one of the most terrible pandemics around the world. Suitable candidates for investigating the potential in counteracting the transmission of HIV infection have been positively screening from various kinds of plants (Mahmood et al., 1993; Lim et al., 1997; Kobayashi et al., 2000; Ma et al., 2000; Tamura et al., 2006). 3,4,5-TriCQA is suggested to depress the transmission of HIV infection by the inhibition of the virus integrase (Tamura et al., 2006) and specific binding to the virus glycoprotein, gp120, which prevents its interaction with CD4 on T-lymphocytes and thus inactivates virus infectivity (Mahmood et al., 1993).
A pathogenic hallmark of Alzheimer‘s disease is the formation of senile plaques. β- Amyloid peptide (Aβ) is a major component of these plaques. Aβ is shown to have the potential to induce oxidative stress and inflammation in the brain, which are postulated to play important roles in the pathogenesis of Alzheimer‘s disease. Aβ induces the production of hydrogen peroxide and lipid peroxide in neurons. In addition, Aβ has been reported to induce superoxide and proinflammatory cytokines in astrocytes as well as in microglial cells.
Antioxidant such as α-tocopherol protect against cytotoxicity in vitro as well as learning and memory deficits induced by Aβ. Furthermore, α-tocopherol and anti-inflammatory agents such as indomethacin reportedly slow the progression of Alzheimer‘s disease (Sano et al., 1997; Rogers et al., 1993). Long-term administration of FA, a phenolic compound, with potent antioxidant and anti-inflammatory activities, induces resistance to Aβ1-42 toxicity in the brain (Yan et al., 2001). Administration of diCQA to Alzheimer-model rats protects against the aging, especially learning and memory deficits induced by Aβ (Isoda et al., 2006).
R
ELATIONSHIP OFF
UNCTIONALC
OMPONENT ANDS
TRUCTURE The structural feature responsible for the antioxidative and free radical-scavenging activity of CA is the ortho-dihydroxyl functionality in the catechol (Mahmood et al., 1993).The cathecol structure also plays an important role in the strong antimutagenicity of anthocyanin pigments (Yoshimoto et al., 2001). Therefore, the physiological function of the
CQA derivatives with plural caffeoyl groups is more effective than with a monocaffeoyl one.
The radical scavenging activity and the antimutagenicity of these derivatives in order of efficacy is triCQA > diCQAs > monoCQA, suggesting that the number of caffeoyl groups bound to QA plays a role in the radical scavenging activity of the CQA derivatives. In other words, additional caffeoyl groups bound to QA are necessary for higher function. The 3,4,5- triCQA exhibits a greater selective inhibition of HIV replication than other CQA derivatives (Mahmood et al., 1993; Tamura et al., 2006). Thus, although there is no direct association, the CQA derivatives have the potential to protect humans from various kinds of diseases.
Especially 3,4,5-triCQA shows remarkable activities for various kinds of physiological functions (Yoshimoto et al., 2002b; Matsui et al., 2004a; Mishima et al., 2005). ChA and diCQA derivatives have been isolated from various plants including sweet potato (Walter et al., 1979; Shimozono et al., 1996), but there are very few reports on 3,4,5-triCQA. Several varieties of sweet potato contain a high content of 3,4,5-triCQA (Islam et al., 2002a; 2003a), suggesting that the sweet potato leaf is a source of not only mono- and diCQA derivatives but also 3,4,5-triCQA. A large scale purification of 3,4,5-triCQA from sweet potato leaves is established in KONARC (unpublished data).
As reviewed previously, sweet potato anthocyanins have been reported to possess multifaceted action, including antioxidation, antimutagenicity, anti-inflammatory, and anticarinogenesis. Extensive structure-activity studies have shown that the number of sugar units and hydroxyl groups on aglycons is associated with biological activities of anthocyanins. The activities appear to increase with a decreasing number of sugar units, and with an increasing number of hydroxyl groups on aglycons (Yoshimoto et al., 2001; Hou et al., 2004). Oral intake of anthocyanins from purple sweet potato and red cabbage color suppresses rat colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) and 2-amino-1 methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) (Hagiwara et al, 2002). Of the six anthocyanins tested, only those with an ortho-dihydroxyphenyl structure on the B-ring suppressed 12-O-tetradecanoylphorbl-13-acette (TPA)-induced cell transformation and activator protein-1 transactivation, suggesting that the ortho-dihydroxypehnyl may contribute to the inhibitory action (Hou et al., 2003). The structural feature responsible for the antioxidative and free radical scavenging activity of CA is the ortho-dihydroxyl functionality in the catechol (Son and Lewis., 2002). These activities might depend on the number of hydroxyl group in the structure (Yoshimoto et al., 2001; Hou, 2003). Cyanidin containing two hydroxyl groups shows stronger activity on antimutagenicity than that of peonidin, which has only one group (Yoshimoto et al., 1999b; 2001). Based on additional studies with enzyme activity, the cyanidins protect against the mutagenesis partly by direct reactions with enzymatically activated carcinogens (heterocyclic amines) rather than by the interaction with metabolic enzyme (Yoshimoto et al., 1999b).
S
WEETP
OTATOU
SE FORN
ON- F
OODSweet potato root is used to make various processed food and food materials, such as juice, natural food colorant, confectionery, shochu, and starch. This process unavoidably discharged wastes and the cost of disposing of these wastes is a main cause of lowering profitability of food processors. In such a circumstance, it is an important question to find
ways to use effectively the wastes from food processing. In Japan, studies are actively conducted clarify the characteristics of these wastes and to develop recycling technology. The subjects of these studies include the method of converting wastes from starch production into biodegradable plastics and recycling of waste liquids from shochu making not merely as feed and manure but also as biodegradable farming materials and foods.
Treatment of sweet potato waste derived from shochu, starch, and leaves is important in the southern Kyushu area in Japan. Shochu waste is used as a raw material of a vinegar-like beverage (Yoshimoto et al., 2004) and bread (Sho et al., 2008) with high content of polyphenolics. Research of polyphenolic composition in shochu waste demonstrates the enzymatic hydrolysis of CQA derivatives to CA and QA in shochu fermentation process by koji, fungi for traditional fermented products in Japan (Yoshimoto et al., 2005a). CA is a raw material for environmentally degradable, high-performance thermoplastics (Kaneko et al., 2006). Furthermore ethyl caffeate isolated from sweet potato shochu distillery by-products inhibits weed seed germination and radical elongation, suggesting a potential as herbicide (Okuno et al., 2006). Sweet potato leaves also can be used as an animal feed for egg-laying hens (Takenoyama et al., 2007) and beef cattle (Takenoyama et al., 2008). Sweet potato leaves contains high content of polyphenolics (Islam et al., 2002a ) and the leaf extract is used in cosmetics. Starch waste fiber from sweet potato is industrially used for the material of environmentally degradable sheets for agriculture.
C
ONCLUSIONSSweet potato root is a resource of anthocyanin pigments with thermo- and photostability.
Furthermore, anthocyanin composition in sweet potato affects not only the quality of food colorants (Odake et al., 1994) and paste color (Yoshinaga et al., 1999) but also physiological activities (Islam et al., 2002b; Yoshimoto et al., 1999a, 2001). KONARC (Japan) is currently focusing on development of new varieties of sweet potato with different pigment composition and more thermo- and photostable pigments.
Sweet potato leaves have been shown to contain higher levels of oxalic acid than leafy vegetables from temperate climate, highest being reported in spinach (Evensen and Standal 1984). Oxalate concentrations in food crops have long been a concern in human diet, because of the negative health effects associated with high intake of oxalate levels that can cause acute poisoning, resulting in hypocalcaemia. Furthermore, oxalic acid and soluble oxalates can bind calcium, reducing its bioavailability and humans poorly utilize calcium oxalate itself. The average content of oxalic acid of sweet potato variety ―Suioh‖ leaves is 280 mg/ 100 g fresh weight. This content is not high compared with the 930 mg/100 g fresh weight in spinach (Ishiguro et al., 2004b). Oxalic acid contents of other sweet potato varieties tested are also several times less than that of spinach (Yoshimoto et al., 2002a).
Sweet potato contains various kinds of physiologically functional components in roots and leaves, which have the potential to maintain human health and mitigate the diseases.
However, much of the evidence is based on research using rats and cell cultures and there is no evidence to directly support benefit to humans. Therefore, moderate consumption of these functional components through the intake of the products may be linked with the chemoprevention of the diseases, further epidemiological and efficacy studies on this aspect
are required. In the worldwide food shortage and increasing food prices, sweet potato is a crop that can contribute to the effective use as not only foods with various kinds of physiological functions, but also the natural resources and the reduction in environmental load.
R
EFERENCESAlves-Rodrigues, A. and Shao, A. (2004). The science behind lutein. Toxicology Letters. 150:
57-83.
Ames, B.N., McCann, J. and Yamasaki, E. (1975). Methods for detecting carcinogens and mutagens with Salmonella/mammalian microsome mutagenicity test. Mutat. Res. 31:
347-364.
AVRDC ( Asian Vegetable Research and Development Center) (1985). Composition of edible fiber in sweet potato tips. AVRDC Prog. Rep. 1985: 310-313.
Barnes, W.A., Maiello, J. and Weisburger, J.H. (1983) In vitro binding of the food mutagen 2-amino-3-methylimidazo-[4,5-f`]quinoline to dietary fibers. J. Natl. Cancer Inst. 70:
757-760.
Bates, C.J. (1995). Vitamin A. The lancet. 345: 31-35.
Berenblum, I. (1941). The mechanism of carcinogenesis. A study of the significance of co- carcinogenic action and related phenomena. Cancer Res. 1: 807-814.
Bub, A., Watzl, B., Heeb, D., Rechkemmer, G. and Briviba, K. (2001). Malvidin-3-glucoside bioavailability in human after ingestion of red wine, dealcholized red wine and red grape juice. Eur. J. Nutr. 40: 113-120.
Cao, G., Muccitelli, H.U., Sanchez-Moreno, C. and Prior, R.L. (2001). Anthocyanins are absorbed in glycated forms in elderly women: a pharmacokinetic study. Am. J. Clin. Nutr. 73: 997-1006.
Cevallos-Casals, B.A. and Cisneros-Zevallos, L. (2003). Stoichiometric and kinetic studies of phenolic antioxidants from Andean purple corn and red-fleshed sweet potato. J. Agric.
Food Chem. 51: 3313-3319.
Chuda, Y., Ono, H., Ohnishi-Kameyama, M., Nagata, T. and Tsushida., T. (1996). Structural identification of two antioxidant quinic acid derivatives from garland (Chrysanthemum curonarium L.). J. Agric. Food Chem. 44: 2037-2039.
Coseteng, M.Y. and Lee, C.Y. (1987). Changes in apple polyphenoloxidase and polyphenol concentrations in relation to degree of browning. J. Food Sci. 52: 985-989.
De Almeida, L.B., Penteado, M.deV.C., Simpson, K.L., Britton, G., Acemoglu, M. and Eugster, C.H. (1986). Isolation and characterization of (5R,6S,5’R,8’R)- and (5R,6S,5’R,8’S)-luteochrome from Brazilian sweet potatoes (Ipomoea batatas LAM).
Helv. Chim. Acta 69: 1554-1558.
Duell, B. (1983). Anthropological problems connected with the introduction and diffusion of the sweet potato into Japan (I). J. Int. Coll. Comm. Econ. 28: 47-62.
Englyst, H.N., Bingham, S.A., Runswick, S.A., Collinson, E., and Cummings, J.H. (1988).
Dietary fiber (non-starch polysaccharides) in fruit, vegetables and nuts. J. Human Nutr.
Dietet. 1: 247-286.
Evensen, S.K. and Standal, B.R. (1984). Use of tropical vegetables to improve diets in the Pacific region. HITAHR Res. Ser. 028, HITAHR, University of Hawaii.
Furuta, S., Suda, I., Nishiba, Y. and Yamakawa, O. (1998). High tert-btylperoxyl radical scavenging activities of sweet potato cultivars with purple flesh. Food Sci. Technol. Int.
Tokyo 4: 33-35.
Gazzaniga, J.M. and Lupton, J.R. (1987). Dilution effect of dietary fiber sources: An in vivo study in the rat. Nutr. Res. 7: 1261-1268.
Goda, Y., Shimizu, T., Kato, Y., Nakamura, M., Maitani, T., Yamada, T., Terahara, N. and Yamaguchi, M. (1997). Two acylated anthocyanins from purple sweet potato.
Phytochemistry 44: 183-186.
Goto, Y., Toyoda, T. and Oikawa, S. (1989). Long-term treatment of BAY g 5421 (Acarbose) in NIDDM. Yakuri to Chiryo 17: 387-401 [In Japanese].
Hagerman, A.E., Riedl, K.M., Jones, G.A., Sovik, K.N., Ritchard, N.T., Hartzfeld, P.W. and Riechel, T.L. (1998). High molecular weight plant polyphenolics (tannins) as biological antioxidants. J. Agric. Food Chem. 46:1887-1892.
Hagiwara, A., Yoshino, H., Ichihara, T., Kawabe, M., Tamano, S., Aoki, H., Koda, T., Nakamura, M., Imaida, K., Ito, N. and Shirai, T. (2002). Prevention by natural food anthocyanins, purple sweet potato color and red cabbage color, of 2-amino-1-methyl-6- phenylimidazo [4,5-b]pyridine (PhIP)-associated colorectal carcinogenesis in rats initiated with 1,2-dimethylhydrazine. J. Toxicol. Sci. 27: 57-68.
Halliwell, B. (1992). The role of oxygen radicals in human disease, with particular reference to vascular system. Haemostasis 23 (Suppl. 1): 118-126.
Halliwell, B. (1994). Free radicals and antioxidants, a personal view. Nutr. Rev. 59: 1057- 1059.
Harada, K., Kano, M., Takayanagi, T., Yamakawa, O. and Ishikawa, F. (2004). Absorption of acylated anthocyanins in rats and humans after ingesting an extract of Ipomoea batatas purple sweet potato tuber. Biosci. Biotechnol. Biochem. 68: 1500-1507.
Harborne, J.B. (1980). Plant phenolics. In: Bell, E.A. and Charlwood, E.V.(Eds.), Encyclopedia of Plant Physiology, New Series, Vol. 8. Berlin, Germany: Springer Verlag, pp. 329-402.
Harborne, J.B. and Grayer, R.J. (1988). The anthocyanins. In: Harborne, J.B. (Ed.)., The Flavonoids, London, Chapman and Hall, pp. 1- 20.
Hauri, H., Wacker, H., Rickli, E., Meier, B., Quaroni, A. and Semenza, G. (1982).
Biosynthesis of sucrose-isomaltase. J. Biol. Chem. 257: 4522-4528.
Hayase, F. and Kato, H. (1984). Antioxidative components of sweet potatoes. J. Nutr. Sci.
Vitaminol. 30: 37-46.
Hayashi, K., Ohara, N. and Tsukui, A. (1996). Stability of anthocyanins in various vegetables and fruits. Food Sci. Technol. Int. 2: 30-33.
Holloway, W.D. (1983). Composition of fruit, vegetable and cereal dietary fibre. J. Sci. Food Agric. 34: 1236-1240.
Holloway, W.D. and Grieg, R. (1984). Water-holding capacity of hemicelluloses from fruits, vegetables and wheat bran. J. Food Sci. 49: 1632-1633.
Holloway, W.D., Monro, J.A., Gurnsey, J.C., Pomare, E.W., and Stace, N.H. (1985). Dietary fiber and other constituents of some Tongan foods. J. Food Sci. 50: 1756-1757.
Hou, D.-X. (2003). Potential mechanisms of cancer prevention by anthocyanins. Current Mol.
Med. 3: 149-159.
Hou, D.-X., Ose, T., Lin, S., Harazor, K., Imamura, I., Kubo, M., Uto, T., Teraha, N., Yoshimoto, M. and Fujii, M. (2003). Anthocyanins induce apoptosis in human promyelocytic leukemia cells: Structure-activity relationship and mechanisms involved.
Int. J. Oncol. 23: 705-712.
Hou, D-X., Kai, K., Li, J-J., Lin, S., Terahara, N., Wakamatsu, M., Fujii, M., Young, M.R.
and Colburn, N. (2004). Anthocyanins inhibit activator protein 1 and cell transformation:
Structure-activity relationship and molecular mechanisms. Carcinogenesis 25: 29-36.
Huang, M.T. and Ferraro, T. (1991). Phenolic compounds in food and cancer prevention. In:
Huang, M.T.., Ho, C. T. and Lee, C.Y. (Eds.), Phenolic Compounds in Food and Their Effects on Health: Antioxidant Cancer Prevention. ACS Symp. Ser. 5078. Amer. Chem.
Soc., Washington, D.C., U.S.A, pp. 220-238..
Idota, T., Kawakami, H. and Nakajima, I. (1994). Growth-promoting effects of N- acetylneuraminic acid-containing substances on bifidobacteria. Biosci. Biotech. Biochem. 58: 1720-1722.
Ishiguro, K., Kumagaqi, Y., Kai, Y., Nakazawa, Y. and Yamakawa, O. (2002a). Genetic resources and breeding of sweet potato in Japan. In: Rmanatha, R., Campilan, D.
(Eds.),.Exploring the Complementarities of in situ and ex situ Conservation Strategies for Asian Sweet potato Genetic Resources, Proceeding of the 3rd International Workshop of the Asian Network for Sweet Potato Genetic Resources; Bali, Indonesia; 2002 Oct 2-4.
Indonesia: Asian Network for Sweet potato Genetic Resources, pp. 57-61.
Ishiguro, K., Toyama, J., Islam, M.S., Yoshimoto, M., Kumagai, T., Kai, Y., Nakazawa, Y.
and Yamakawa, O. (2004a). Suioh, a new sweet potato cultivar for utilization in vegetable greens. Acta Hort. 637: 339-345.
Ishiguro, K., Toyama, J. and Yoshimoto, M. (2004b). Portional differences of nutrition and physiological function in ―Suioh‖, a sweet potato cultivar for top utilization. Rep. Kyushu Br. Crop Sci. Soc. Japan 70: 36-39.
Ishiguro, K., Yahara, S. and Yoshimoto, M. (2007a). Changes in polyphenolic content and radical scavenging activity of sweet potato (Ipomoea batatas L.) during storage at optimal and low temperatures. J. Agric. Food Chem. 55: 10773-10778.
Ishiguro, K. and Yoshimoto, M. (2006). Content of an eye-protective nutrient lutein in sweet potato leaves. Acta Hort. 703: 253-256.
Ishiguro, K., Yoshimoto, M., Tsubata, M., and Takagaki, K. (2007b). Hypertensive effect of sweet potato tops. Nippon Shokuhin Kagaku Kogaku Kaishi 54: 45-49 [In Japanese with English summary].
Islam, M.S. (2005). Distribution and physiological functions of caffeoylquinic acid derivatives in leaves of sweet potato genotype sweet potato (Ipomoea batatas L.) leaf: Its potential effect on human health and nutrition. J. Food Sci. 71: 13-21.
Islam, M.S., Yoshimoto, M. and Yamakawa, O. (2003a). Distribution and physiological functions of caffeoylquinic acid derivatives in leaves of sweet potato genotypes. J. Food Sci. 68: 111-116.
Islam, M.S., Yoshimoto, M., Yahara, S., Okuno, S., Ishiguro, K. and Yamakawa, O. (2002 a).
Identification and characterization of foliar polyphenolic composition in sweet potato (Ipomoea batatas L.) genotypes. J. Agric. Food Chem. 50: 3718-3722.
Islam, M.S. and Jalaluddin, M. (2004). Sweet potato—a potential nutritionally rich multifunctional food crop for Arkansas. J. Arkansas Agric Rural Dev 4:3–7.
Islam, M.S. and Jalaluddin, M. (2005). Antimicrobial activities of Ipomoea batatas leaves grown under different environmental conditions. Proceedings of the 49th Annual Rural Life Conference; 2005 Feb 11; Univ. of Arkansas, Pine Bluff, Ark. Pine Bluff, USA:
Univ. of Arkansas. p. 23.
Islam, M.S. and Jalaluddin, M., Garner, J., Yoshimoto, M. and Yamakawa, O. (2005).
Artificial shading and temperature influenced on anthocyanin composition of Ipomoea batatas leaves. HortScience 40: 76–80.
Islam, M.S., Yoshimoto, M., Ishiguro, K., Okuno, S. and Yamakawa, O. (2003b). Effect of artificial shading and temperature on radical scavenging activity and polyphenolic compositions in sweet potato leaves. J Am Soc Hortic. Sci. 128: 182–187.
Islam, M.S., Yoshimoto, M., Ishiguro, K. and Yamakawa, O. (2003c). Bioactive and functional properties of Ipomoea batatas L. leaves. Acta Hort. 628: 693–699.
Islam, M.S., Yoshimoto, M., Terahara, N. and Yamakawa, O. (2002b). Anthocyanin compositions in sweet potato leaves. Biosci. Biotechnol. Biochem.. 66: 2483–2486.
Isoda,H., Kan, S. and Shigemori, H. (2006). Agents for the prevention or treatment of Alzheimer, food and drink. Patent JP2007/052151.
Itoh, T. and Kai, A. (1997). Epidemiology of infection of enterohemorrhagic Escherichia coli O157: H7 in Japan. J. Food Hyg. Soc. Jpn. 38: 275-285 [In Japanese with English summary].
Kada, T., Kato, M., Aikawa, K. and Kiriyama, S. (1984). Adsorption of pyrolysate mutagens by vegetable fibers. Mutat. Res.141: 149-152.
Kamei, H., Kojima, T. and Hasegawa, M. (1995). Suppression of tumor cell growth by anthocyanins in vitro. Cancer Invest. 13: 590–594.
Kaneko, T., Thi, T.H., Shi, D.J. and Akashi, M. (2006). Environmentally degradable, high- performance thermoplastics from phenolic phytomonomers. Nature Materials 5: 966- 970.
Kaul, A. and Khanduja, K.L. (1998). Polyphenols inhibit promotional phase of tumorigenesis:
relevance of superoxide radicals. Nutr. Cancer 32: 81-85.
Kimura, M., Kobori, C.H., Rodriguez-Amaya, D.B., and Nstel, P. (2006). Screening and HPLC methods for carotenoids in sweet potato, cassava and maize for plant breeding trials. Food Chem. 100: 1734-1746.
Kobayashi, Y., Watanabe, M., Ogihara, J., Kato, J. and Oishi, K. (2000). Inhibition of HIV-1 reverse transcriptase by methanol extracts of commercial herbs and spices. Nippon Shokuhin Kagaku Kogaku Kaishi 47: 642-645 [In Japanese with English summary].
Konczak-Islam, I., Nakatani, M., Yoshinaga, M. and Yamakawa, O. (2001). Effect of ammonium ion and temperature on anthocyanin composition in sweet potato cell suspension culture. Plant Biotechnol. 18: 109-117.
Konczak-Islam, I., Yoshimoto, M., Hou, D.-X., Terahara, N. and Yamakawa, O. (2003).
Potential chemopreventive properties of anthocyanin-rich aqueous extracts from in vitro produced tissue of sweet potato (Ipomoea batatas L). J. Agric Food Chem. 51: 5916- 5922.
Konczak-Islam, I., Yoshinaga, M., Nakatani, M., Yamakawa, O. and Terahara, N. (2000).
Establishment and characteristics of an anthocyanin-producing cell line from sweet potato storage root. Plant Cell Rep. 19: 472-477.
Konczak, I. and Zhang, W. (2004). Anthocyanins-more than nature‘s colours. J. Biomed.
Biotechnol. 5: 239-240.
Kozai, T., Kubota, C. and Kitaya, Y. (1996). Sweet potato technology for solving the global issues on food, energy, natural resources and environmental in the 21st century. Environ.
Control in Biol. 34: 105-114 [In Japanese].
Knekt, P., Jarvinen, R., Reunanen, A. and Maatela, J. (1996). Flavonoid intake and coronary mortality in Finland: a cohort study. Br. Med. J. 312: 478–81.
Kurata, R., Adachi, M., Yamakawa, O. and Yoshimoto, M. (2007). Growth suppression of human cancer cells by polyphenolics from sweet potato (Ipomoea batatas L.) leaves. J.
Agric. Food Chem. 55: 185-190.
Larsen, E., Kharazami, A.,Christensen, L.P. and Christensen, S.B. (2003). An antiinframmatory galactolipid from rose hip (Rosa canina) that inhibits chemotaxis of human peripheral blood neutrophils in vitro. J. Nat. Prod. 66: 994-995.
Levin, G. and Mokady, S. (1994). Antioxidant activity of 9-cis compared to all-trans ß- carotene in vitro. Free Radical Biol. Med. 17: 77-82.
Lim, Y.A., Kojima, S., Nakamura, N., Miyashiro, H., Fushimi, H., Komatsu, K., Hattori, M., Shimotohno, K., Guputa, M.P. and Correa, M. (1997). Inhibitory effects of Cordia spinescens extracts and their constituents on reverse transcriptase and protease from human immunodeficiency virus. Phytother. Res. 11: 490-495.
Lugasi, A., Almedia, D.P.E. and Dworschak, E. (1999). Chlorogenic acid content and antioxidant properties of potato tubers as related to nitrogen fertilization. Acta Aliment.
28: 183-195.
Lund, E. D. (1984). Cholesterol binding capacity of fiber from tropical fruits and vegetables.
Lipids 19: 85-90.
Ma, C.-M., Nakamura, N. and Hattori, M. (2000). Chemical modification of oleanene type tri-terpenes and their inhibitory activity against HIV-1 protease dimerization. Chem.
Pharm. Bull. 48: 1681-1688.
Mahfudz, L.D., Hayashi, K., Ikeda, M., Hamada, K., Ohtsuka, A. and Tomita, Y. (1996). The effective use of shochu distillery by product as a source of broiler feed. Jpn. Poult. Sci. 33: 1-7.
Mahmood, N., Moore, P.S., De Tommasi, N., De Simone, F., Colman, S., Hay, A.J. and Pizza, C. (1993). Inhibition of HIV infection by caffeoylquinic acid derivatives. Antiviral Chem. Chemother. 4: 235-240.
Mangels, A.R., Holden, J.M., Breecher, G.R., Forman, M.R. and Lanza, E. (1993). Carotenid content of fruits and vegetables: An evaluation of analytic data. J. Am. Diet. Assoc. 93:
284-296.
Maoka, T., Akimoto, N., Ishiguro, K., Yoshinaga, M. and Yoshimoto, M. (2007). Carotenoids with a 5, 6-dihydro-5,6-dihydroxy--end group, from yellow sweet potato‖Benimasari‖, Ipomoea batatas LAM. Phytochemistry 68: 1740-1745.
Matsui, T. (2002). Prophylaxis of hypertension by food components and their antihypertensive mechanism. Bioscience and Industry 60: 25-30 [In Japanese].
Matsui, T., Ebuchi, S., Fujise, T., Abesundara, K.J.M., Doi, S., Yamada, H. and Matsumoto, K. (2004a). Strong anti-hyperglycemic effects of water-soluble fraction of Brazilian Propolis and its bioactive constituent, 3,4,5-tri-O-caffeoylquinic acid. Biol. Pharm. Bull.
27: 1797-1803.
Matsui, T., Ebuchi, S., Fukui, N.Matsugano, K., Terahara, N. and Matsumoto, K. (2004b).
Caffeoylsophorose, a new natural α-glucose inhibitor, from red vinegar by fermented purple-fleshed sweet potato. Biosci. Biotechnol. Biochem. 68: 2239-2246.