The formation of electrostatic complexes of gum Arabic (GA) with chitosan (Ch), two oppositely charged polysaccharides, as a function of the biopolymers ratio (RGA/Ch), total biopolymers concentration (TBconc), pH, and ionic strength, was investigated. The conditions under which inter-biopolymer complexes form were determined by using turbidimetric and electrophoretic mobility measurements in the equilibrium phase and by quantifying mass in the precipitated phase. Results indicated that optimum coacervate yield was achieved at RGA/Ch = 5, independently of TBconc at the resulting pH of solutions under mixing conditions. High coacervate yields occurred in a pH range from 3.5 to 5.0 for RGA/Ch = 5. Coacervate yield was drastically diminished at pH values below 3.5 due to a low degree of ionization of GA molecules, and at pH values above 5 due to a low solubility of chitosan. Increasing ionic strength decreased coacervate yield due to shielding of ionized groups.

Plant tissue cultures represent a potential source for producing secondary metabolites. In this work, Buddleja cordata tissue cultures were established in order to produce phenylpropanoids (verbascoside, linarin and hydroxycinnamic acids), as these metabolites are credited with therapeutic properties. Highest callus induction (76.4-84.3%) was obtained in five treatments containing 2,4-Dichlorophenoxyacetic acid (2,4-D: 0.45-9.05 lM) with Kinetin (KIN: 2.32, 4.65 lM), whereas highest root induction (79.6%) corresponded to the a-Naphthaleneacetic acid (9.05 lM) with KIN (2.32 lM) treatment. Verbascoside was the major phenylpropanoid produced in in vitro cultures (root, white and green callus) [66.24-86.26 mg g -1 dry weight (DW)], while linarin and hydroxycinnamic acid production was low (0.95-3.01 mg g -1 DW). Verbascoside and linarin production were improved in cell suspension culture (116 mg g -1 DW and 8.12 mg g -1 DW, respectively).

Sphaeralcea angustifolia, an endangered plant species in Mexico, is employed to treat inflammatory processes and as a wound healing remedy. Scopoletin (1) was reported as one of the main bioactive compounds in this plant. Here, we isolated and identified compounds with anti-inflammatory properties from the suspension-cultured cells of S. angustifolia. The CH2Cl2 : CH3OH extract of the cells exhibited anti-inflammatory properties in acute inflammation models. Two compounds were isolated, 5-hydroxy-6,7-dimethoxycoumarin, named tomentin (2), and 2-(1,8-dihydroxy-4-isopropyl-6-methyl-7-methoxy)-naphthoic acid, denominated as sphaeralcic acid (3). Their structures were determined by spectroscopic and spectrometric analyses. The anti-inflammatory effects of both compounds were also evaluated. At a dose of 45 mg/kg, compound 2 inhibited the formation of λ-carrageenan footpad edema at 58 %, and compound 3 at 66 %. Local application of compound 2 (225 mM per ear) or 3 (174 mM per ear) inhibited the phorbol ester-induced auricular edema formation by 57 % or 86 %, respectively. The effect of compound 3 was dose-dependent and the ED50 was 93 mM.

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Betalains are plant pigments of hydrophilic nature with demonstrated chemopreventive potential in cancer cell lines and animal models. Among the betalains, those containing an aromatic moiety with two free hydroxyl groups possess the strongest antioxidant and free radical scavenging activities. The betaxanthins dopaxanthin and miraxanthin V and the betacyanins betanidin and decarboxy-betanidin are the only natural betalains with catecholic substructures. These four pigments have been produced in cell cultures established from hypocotyls of the plant Celosia argentea. Two stable and differentially colored cell lines, yellow and red, were maintained on Murashige and Skoog medium supplemented with the plant growth regulators 6-benzylaminopurine (6.66 μM) and 2,4-dichlorophenoxyacetic acid (6.79 μM). Derived suspension cultures showed increased production of dihydroxylated betalains in the cells and secreted to the medium with a maximum reached after 8 days of culture. In addition, precursor molecules betalamic acid and dopamine, with content up to 42.08 mg/g dry weight, were also obtained. The joint presence of the bioactive betalains together with the production of dopamine and betalamic acid show the ability of cell cultures of C. argentea to become a stable source of valuable phytochemicals.

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