The antibacterial activities of 81 edible plants against the dental caries pathogen Streptococcus mutans were investigated. The fresh vegetative crude extracts were subjected to the paper disc method. Furthermore, in order to fractionate the active component, hexane, ethyl acetate and methanol extracts from freeze-dried samples were also examined. Antibacterial activities were positive in 17 samples, including cinnamon and Japanese ginger. Among these, the stabilities of the active components against heat treatment or storage at 4 ℃ for one week were also investigated. Following these treatments, the activities of balsam pear and garlic extracts were lost, while the active components in ginger, Japanese ginger, clove and cinnamon appeared. Samples of the genus Zingiberaceae, including Japanese ginger and ginger, contained abundant and stable antibacterial components acting against S. mutans.

γ-Linolenic acid (GLA) has the physiological functions of modulating immune and inflammatory responses. We produced structured TAG rich in 1,3-dicapryloyl-2-γ-linolenoyl glycerol (CGC) from GLA-rich oil (GLA45 oil; GLA content, 45.4 wt%), which was prepared by hydrolysis of borage oil with Candida rugosa lipase having weak activity on GLA. A mixture of GLA45 oil/caprylic acid (CA) (1:2, w/w) was continuously fed into a fixed-bed bioreactor (18 × 180 mm) packed with 15 g immobilized Rhizopus oryzae lipase at 30°C and a flow rate of 4 g/h. The acidolysis proceeded efficiently, and a significant decrease of lipase activity was not observed in full-time operation for 1 mon. GLA45 oil contained 10.2 mol% MAG and 27.2 mol% DAG. However, the reaction converted the partial acylglycerols to structured TAG and tricaprylin and produced 44.5 mol% CGC based on the content of total acylglycerols. Not only FFA in the reaction mixture but also part of the tricaprylin and partial acylglycerols were removed by molecular distillation. The distillation resulted in an increase of the CGC content in the purified product to 52.6 mol%. The results showed that CGC-rich structured TAG can efficiently be produced by a two-step process comprising selective hydrolysis of borage oil using C. rugosa lipase (first step) and acidolysis of the resulting GLA-rich oil with CA using immobilized R. oryzae lipase (second step).Paper no. J10117 in JAOCS 79, 871-877 (September 2002).KEY WORDS: Acidolysis, borage oil, immobilized lipase, γ-linolenic acid, Rhizopus oryzae, selective hydrolysis, structured triacylglycerol.γ-Linolenic acid (18:3n-6; GLA) is biosynthesized from linoleic acid (18:2n-6; LnA) by ∆6 desaturase, which is the rate-limiting enzyme in the essential FA cascade (1,2) and is an intermediate precursor of local hormones (prostaglandins, thromboxanes, and leukotrienes) (3). The FA has the physiological functions of modulating immune and inflammatory responses (4) and is effective for treating atopic eczema (5,6) and rheumatoid arthritis (7,8). Thus, GLA-containing oil, especially borage oil, is used as a health food and an ingredient in infant formulas (9).Recently, structured TAG with medium-chain FA at the 1,3-positions and long-chain FA at the 2-position (MLMtype) were reported to be absorbed extensively into intestinal mucosa (10,11). Therefore, structured TAG containing functional FA are expected to act as nutrients for patients with poor digestion and malabsorption of lipids and as health foods for the elderly. Structured TAG can be produced by exchanging FA in natural oils and fats with medium-chain FA using an immobilized 1,3-specific lipase (12-15).We reported that MLM-type structured TAG containing GLA were produced by acidolysis of borage oil with caprylic acid (8:0, CA) using immobilized Rhizopus oryzae (the former name of R. delemar) lipase (16). However, because borage oil consisted of TAG esterified with not only GLA but also LnA and oleic acid (18:1n-9; OA) at the 2-position, the content of 1,3-dicapryloyl-2-γ-linolenoyl g...

The anti-tumor promoting activities of 120 kinds of edible plants against the non TPA-type promoter, okadaic acid (OA), were investigated by measuring suppression of the inhibitory effect of OA on protein phosphatase-2A (PP2A), since OA promotes tumor formation by inhibiting this enzyme. One quarter of the tested samples showed activity over 20%. In particular, 8 kinds of plants (basil (100%), peppermint (100%), carrot leaf (100%), broccoli (100%), nabana (98%), edible burdock (86%), watermelon (99%) and winter fungus (100%)) showed very strong activity. Physicochemical properties of the active components contained in the samples that showed high activity were found that the active component in the major sample was inactivated by cold storage or boiling, and that only edible burdock showed strong activity following both types of processing. Soluble fractions from these samples were obtained by extraction in hexane, benzene, ethyl acetate, methanol and water. Very strong anti-OA activity was observed in water soluble extracts of edible burdock and eggplant, whereas cabbage and broccoli showed activity in the extraction fractions in organic solvents such as hexane. Although the active components in these samples were not identified, these findings suggest that the component with anti-okadaic acid activity must be present in edible plants.

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