Two new Diels-Alder type compounds from cell cultures of Morus alba / 中草药

Objective To investigate the Diels-Alder adducts from cell suspension cultures of Morus alba. Methods A variety of column chromatography (CC) including silica gel CC, Sephadex LH-20 CC, C18 CC, and semi-preparative HPLC were used to separate Diels-Alder adducts from cell cultures of M. alba. Their structures were identified by physicochemical properties and various spectroscopic experiments, including MS, NMR, and ECD. Results Eight Diels-Alder adducts were obtained from the ethyl acetate extract of M. alba, and determined as mongolicin H (1), morbilisin J (2), mongolicin F (3), mulberrofuran G (4), artonin D (5), kuwanon R (6), morbilisin C (7), and mulberrofuran E (8). Conclusion Compounds 1-8 are all Diels-Alder adducts and show medium cytotoxic activity, and compounds 1 and 2 are new compounds.

Antimicrobial activity of Anonna mucosa (Jacq.) grown in vivo and obtained by in vitroculture

Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time.

Stimulation of trans-resveratrol biosynthesis in Vitis vinifera cv. Kyoho cell suspension cultures by 2, 3-dihydroxypropyl jasmonate elicitation

Background: Plant cell suspension culture of Vitis vinifera is a promising technology for investigating different factors that are able to induce and/or modify stilbenes biosynthesis. Jasmonates have been reported to play an important role in a signal transduction pathway that regulates defence responses as well as the production of secondary metabolites. In this study, 2, 3-dihydroxypropyl jasmonate (DHPJA) was used to investigate its effect on stimulating trans-resveratrol (t-R) accumulation and the plant defence responses in Vitis vinifera cv. Kyoho cell suspension cultures for the first time. Results: It demonstrated that DHPJA had superior effects on stilbenoids accumulation over methyl jasmonate (MeJA). The optimal condition was 150 uM DHPJA added on day 15 of cultivation period, with the highest level of t-R accumulation which was increased 1.8-fold and 1.3-fold compared with the control and 150 uM MeJA respectively. DHPJA induced stronger plant defence responses, including oxidative burst and activation of L-phenylalanine ammonia lyase (PAL) than MeJA. H2O2 generation induced by DHPJA played a significant role in enhancing t-R accumulation. Adding a specific inhibitor of H2O2 signalling pathway inhibited DHPJA-induced t-R accumulation, but had no effects on DHPJA-induced other metabolites accumulation, which resulted in regulations of product diversity. Conclusions: This study demonstrated that DHPJA was an efficient elicitor to enhance t-R accumulation by activating stronger oxidative burst, and H2O2 signalling pathway could regulate product diversity in DHPJA-induced V. vinifera cv. Kyoho cell suspension cultures.

Biotransformation of 6β-santonin by Phytolacca acinosa cell suspension cultures / 药学学报

Aim To obtain more valuable derivatives for the further structural modification of 6β-santonin (1) via biotransformation by using cell suspension cultures of Phytolacca acinosa. Methods The substrate 1 was incubated with cell suspension cultures of P.acinosa, the products were obtained by chromatography, and identified on the basis of their physical and spectral data (HRMS, 1D NMR, 2D NMR, NOE and IR). Results After incubation with cell suspension cultures of P.acinosa, 1 was converted into five products (2-6). Among them, 3 is a new compound. Conclusion 6β-santonin could be selectively reduced and hydroxylated by the cell suspension cultures of P.acinosa, which would provide valuable intermediates for its further structural modification.