Yasuhiro Hara

The configuration of methyl jasmonate affects paclitaxel and baccatin III production in Taxus cells.

All stereoisomers of methyl jasmonate (MJA) were prepared, and their effects on cell yield and promotion of paclitaxel (Taxol) and baccatin III production investigated in cell suspension cultures of Taxus media. (3R,7S)-MJA showed the strongest cell growth inhibition, followed by (3R,7R)-MJA. In contrast, (3S,7R)- and (3S,7S)-MJA had very low inhibitory effects, indicating that this inhibition depends largely on the (3R)-configuration. In terms of the promotion of paclitaxel and baccatin III production, (3R,7R)-MJA had the highest activity. Although it showed considerable activity at low concentration, at higher concentrations the activity was decreased due to strong inhibition of cell growth. Interestingly, paclitaxel and baccatin III contents increased even at a high (3S,7R)-MJA concentration, whereas the other isomers had the opposite effects. These findings are interpreted to suggest that the optimum configuration is (3R,7R), the (3R)-configuration not being indispensable, and that the (7R)-configuration is suitable for the promotion of paclitaxel and baccatin III production.

Enhancement of Berberine Production in Suspension Cultures of Coptis japonica by Gibberellic Acid Treatment

Summary The production of berberine by cell cultures of Coptis japonica was enhanced by the addition of gibberellic acid (GA3 10 −8 –10 −5 M) to the medium, particularly in the early stages of the culture period. After 14 days of culture the berberine yield of GA3 treated cells (10 −8 M) was 1660 mg·1 −1 suspension, controls 1230 mg·l −1 . Also, the addition of gibberellic acid suppressed the starch synthesis in the late exponential growth phase. Furthermore, the addition of gibberellic acid altered the rates of incorporation of sucrose and nitrogen into the cells during the early stage of culture. The results suggest that the change in the incorporation rate of main nutrients triggered by gibberellic acid has a marked effect on the synthesis and accumulation of berberine.

Semisynthetic Production of Vinblastine Involving Cell Cultures of Catharanthus Roseus and Chemical Reaction

Vinblastine (VLB) is a rare dimeric alkaloid contained in Catharanthus roseus and used in treating leukemia and malignant lymphoma. Many researchers have studied the production of VLB by plant cell and tissue cultures. So far, there has been no success in producing VLB by undifferentiated cell cultures, but the monomer precursor, catharanthine, can be produced by this way (1). VLB can be produced in multiple shoot cultures of C. roseus but the VLB yield in the cultures is only about 10% of that of the Catharanthus leaves (2). Furthermore, it is difficult to synthesize VLB chemically due to its intricate structure.

Effect of gibberellic acid on berberine and tyrosine accumulation in Coptis japonica

Abstract The enhancement of berberine production by gibberellic acid (GA 3 ) in addition to cell cultures of Coptis japonica was investigated. Coptis cells cultured in the presence of GA 3 gave increases in sucrose uptake, activation of 3-deoxy- d -arabino-heptulosonic acid 7-phosphate (DAHP) synthetase, a putative regulatory enzyme of the shikimate pathway, and free tyrosine levels relative to the controls. The timing of this increase in cellular berberine corresponded closely to the time course of the activation of DAHP synthetase and free tyrosine accumulation. Furthermore, the addition of tyrosine to the medium stimulated berberine production, but only in the presence of GA 3 . We propose that GA 3 treatment contributes to berberine production by activating primary metabolic steps involved in tyrosine biosynthesis.

Phospholipids of membranes of cultured cells and the products of protoplast fusion

Abstract The variety and distribution of phospholipids in the cell membranes of cultured cells and their fatty acid composition were analysed. Membranes of suspension cultured cells of Rauwolfia serpentina var. Bentham, Nicotiana tabacum var. Samsun, Atropa belladonna and Bouvardia ternifolia had almost the same composition of phosphatidylcholine, PC ( ca 50%); phosphatidylethanolamine, PE ( ca 25%); phosphatidylinositol, PI ( ca 10%); phosphatidylglycerol, PG (several %); and phosphatidic acid, PA (several %). We determined the distribution of the molecular species of the three major phospholipid fractions (PC, PE and PI) in R. serpentina and N. tabacum . Membranes of both cell-types contained basically similar molecular species, 1–16:0/2–18:2 the main type, particularly in the PC- and PE- fractions; 1–18:2/2–18:2 and 1–18:0/2–18:2 for R. serpentina ; and 1–16:0/2–18:3, 1-18:0/2-18:3 and 1-18:2/2-18:2 for N. tabacum . The influence of membrane fluidity on protoplast fusion as effected by the phase transition of the phospholipids, is discussed.