Toshio Kawasaki

Components of the ether-insoluble resin glycoside-like fraction from Cuscuta chinensis

A trisaccharide and four new glycosidic acids, named cuscutic acids A-D, along with known organic acids, acetic acid, propionic acid, (2S)-2-methylbutyric acid, tiglic acid, (2R, 3 R)-nilic acid, (11S) convolvulinolic acid and (11S)-jalapinolic acid have been isolated from the alkaline hydrolysate of the ether-insoluble resin glycoside-like fraction of the seeds of Cuscuta chinensis. The compounds were characterized on the basis of chemical and physical data.

Cyanogenic glycosides in leaves of Perilla frutescens var. acuta

Abstract Besides 7-(2-O-β- D -glucuronyl-β- D -glucuronyloxy)-5,3′,4′-trihydroxyflavone, scutellarin, rosmarinic acid and caffeic acid, two cyanogenic glycosides have been isolated from the dried leaves of Perilla frutescens var. acuta. One of them is prunasin and the other is (R)-2-(2-O-β- D -glucopyranosyl-β- D -glucopyranosyloxy)-phenylacetonitrile, a new isomer of amygdalin.

Resin glycosides. I. isolation and structure elucidation of orizabin-I. II. IlI and IV, genuine resin glycosides from the root of Ipomoea orizabensis

Abstract Four compounds named orizabin I, II, III and IV, which are ether-soluble and correspond to the so-called resin glycoside “jalapin” were isolated, for the first time, from the root of Ipomoea orizabensis (Convoi vul aceae). Unlike the presumption advocated by Mannich and Schumann for the ether-insoluble glycoside “convoivulin” from I. purga , all of them were respectively a monomer of hydroxyfatty acid oligoglycoside in which the sugar moiety is partially acylated by organic acids and also combines with the car☐y group of the aglycone to form a macrocyclic ester. Their isolation in a pure state was successfully achieved by a high resolution preparative HPLC in the final step. The structures were determined on the basis of chemical and spectral data and regarded to represent those of genuine ingredients.

Isolation and characterization of a novel type of glycosphingolipid from Neanthes diversicolor

Abstract Five glycosphingolipids were obtained in the pure state from the marine annelid, Neanthes diversicolor. Final isolation of the individual compound was achieved by means of preparative HPLC with a reversed phase column in a recycling mode. They were assigned the structures, 1-O-β- d -6-O-[2′-( trimethylammonio )- ethylphosphoryl ] galactopyranosyl , -N-hexadecanoyl-(4E,8E)-sphingadiene (1), -N-hexadecanoyl-(4E)-sphingenine (2), -N-heptadecanoyl-(4E)-sphingenine (3), -N-octadecanoyl-(4E)-sphingenine (4) and -N-hexadecanoyl-sphinganine (5). It is noted that they are the monogalactosyl ceramides carrying the phosphocholine group in the galactose moiety, and that one of them contains an odd numbered fatty acid residue.

A spirostanol glycoside from Agave cantala

Abstract Two spirostanol glycosides, cantalasaponins -2 and -4 were isolated from the methanolic extract of the rhizomes of Agave cantala and were characterized. The first glycoside was found to be lethal against Biomphalaria glabrata , the snail vector of the disease schistosomiasis, at a concentration of 7 ppm.

Two novel galactosylceramides from Marphysa sanguinea

Two galactosylceramides carrying the phosphocholine group were isolated in the pure state from a marine annelid, Marphysa sanguinea, and their structures were determined. Two galactosylceramides carrying the phosphocholine group were isolated from Marphysa sanguinea, and their structures were determined.

Scammonins VII and VIII, two resin glycosides from Convolvulus scammonia☆

Two minor ether-soluble resin glycosides, scammonins VII and VIII, were isolated from Radix Scammoniae, the roots of Convolvulus scammonia. In addition to (2S)-2-methylbutyric acid and tiglic acid, they are composed, respectively, of orizabic acid A and a new glycosidic acid named scammonic acid B, with similar macrocyclic ester structures to those of the scammonic acid A-based scammonins I-VI. Isolation of genuine scammonins III-V, which were previously obtained as peracetates, is also described.

A new class of ergostane glycosides from tubocapsicum anomalum

Abstract The structures of two new C 28 steroidal lactone glycosides have been established; Spectroscopic and X-ray diffraction analyses of tubocapsigenin A diacetate, one of sapogenol derivative of these glycosides, have presented a new class of steroidal lactone structure.

High resolution nmr and x-ray crystallography data of caudicifolin from Euphorbia acaulis

Abstract A diterpene lactone was isolated from the cold petrol (60−80°) extract of rhizomes of Euphorbia acaulis, a plant material used by a tribe of central India for curing various inflammatory disorder. The diterpene, which was observed to be identical to caudicifolin on the basis of its physical constants, was subjected to high resolution NMR spectroscopy and X-ray crystallography examination. This paper reports the salient features of the 2D 1 H NMR, 13 C NMR and X-ray crystallography data of the compound. 13 C NMR assignments were made by the use of proton noise decoupling, SFORD, APT and automatic spectral editing techniques. 1 H NMR assignments were made with the aid of a COSY experiment for long range couplings and NOE correlated 2D-experiments. The 1 H and 13 C NMR spectral assignments have been further corroborated by H/C correlation experimental results.

Scammonin III–VI, resin glycosides of Convolvulus scammonia

Abstract Four kinds of ether-soluble resin glycosides named scammonins III–VI were obtained as their acetates from Radix Scammoniae (scammony root), the root of Convolvulus scammonia . Their structures have been determined on the bases of chemical and spectral evidences. All of them have a common glycosidic acid, scammonic acid A, and a intramolecular macrocyclic ester structure.