In our previous study, 3) we isolated a xyloglucan from the cell walls of eggplant. This xyloglucan was hydrolyzed with a xyloglucan specific endo 1,4 β D glucanase (xyloglucanase) from Penicillium sp. M451. 4) The resulting hydrolyzate was fractionated by Bio Gel P 2 chromatography. Hexa , hepta and octa saccharide fractions were obtained in a ratio of 35:43:22 as major oligosaccharide fractions. The xyloglucan oligosaccharide fractions were separately subjected to sugar composition and

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... tion analyses, high performance anion exchange chromatography with pulsed amperometric detection (HPAEC PAD), and matrix assisted laser desorption ionization time of the flight mass spectrometry (MALDI TOF MS) before and after treatment with an isoprimeverose producing oligoxyloglucan hydrolase (IPase) purified from Eupenicillium sp. M9 5) or with β D galactosidase from Bacillus circulans. Hexa , hepta and octa saccharide fractions might consist mainly of XXGG, of XLGG, LXGG and XSGG, and of LSGG and LLGG, respectively. This work describes the structural characterization of other minor xyloglucanase derived eggplant xyloglucan oligosaccharides. Unless otherwise stated, all materials and experimental procedures used for this study were the same as those described in a previous paper. 3) Xyloglucan was prepared from the cell walls obtained from the edible portion of eggplants in a manner almost identical with that reported in a previous paper. 3) Eggplant xyloglucan (100 mg as Glc equiv. in 100 mL of 20 mM Na acetate buffer, pH 5.5) was incubated at 40 C with Geotrichum sp. M128 xyloglucanase 6) (0.2 U 0.1 mL), the action pattern on xyloglucan polymers of which is the same as that of Penicillium sp. M451 xyloglucanase. 4) After reaction for 48 h, the incubation mixture was heated for 10 min in a boiling water bath, deionized with Amberlite IR 120 resin (H + ) (about 3 cm 3 ) and filtered through Toyo No. 5 paper. The filtrate (about 100 mL) was concentrated to about 3 mL. A portion of the concentrate was subjected to HPAEC analysis (Fig. 1) . Peaks 6 A, 7 A, B, and D, and 8 A and C corresponded to hexasaccharide XXGG, heptasaccharides LXGG, XLGG and XSGG, and octasaccharides LLGG and LSGG, respectively, which were characterized in a previous work 3) (Fig. 2) . The concentrate of M128 hydrolyzed eggplant xyloglucan was applied to a column (2.3 × 140 cm) of Bio Gel P 2 operated at 40 C and eluted with water; 4.2 mL fractions were collected and assayed for carbohydrate. Tubes 55 57, 58 61, 62 64 and 65 71 were separately combined, concentrated, and rechromatographed on the same column to give nona , octa , hepta , hexa saccharide fractions. Abstract: Further structural study of the xyloglucanase-derived eggplant xyloglucan oligosaccharides was carried out to investigate the oligosaccharide units of xyloglucan from the cell-walls of eggplant in detail. The result shows that a hexasaccharide, XSG, a heptasaccharide, XX2GG, an octasaccharide, LX2GG and a nonasaccahride, LSGGG, in addition to the major oligosaccharides XXGG, LXGG, XLGG, XSGG, LLGG and LSGG, the structures of which were previously reported, are included in oligosaccharide units of eggplant xyloglucan. LSGGG are the abbreviated names for xyloglucan oligosaccharides according to the nomenclature of Fry et al. [Ref. 1, 2) Each (1 4) β linked D glucosyl residue in the backbone is given a one letter code according to its substituents: G = β D Glc; X = α D Xyl (1 6) β D Glc; L = β D Gal (1 2) α D Xyl (1 6) β D Glc; S = α L Ara (1 2) α D Xyl (1 6) β D Glc; X2 = α L Xyl (1 2) α D Xyl (1 6) β D Glc]. IPase, isoprimeverose producing oligoxyloglucan hydrolase; HPAEC, high performance anion exchange chromatography; PAD, pulsed amperometric detection; MALDI TOF MS, matrix assisted laser desorption ionization time of the flight mass.