Response of Biomass Development,Essential Oil,and Composition of Plectranthus amboinicus (Lour.) Spreng. to Irrigation Frequency and Harvest Time

A greenhouse experiment was conducted to study the effects of four irrigation intervals (4, 8, 12, and 16 days) and six harvests (2, 4, 6, 8, 10, and 12 months after transplanting) on biomass, essential oil content, and composition of Plectranthus amboinicus (Lour .) Spreng . Fresh weight and essential oil yield decreased with increasing irrigation interval; whereas, essential oil content was stimulated by water stress and increased as the irrigation interval increased. Fresh weight of Plectranthus amboinicus irrigated every 4 days peaked when harvested at 6 months, but essential oil content peaked when irrigated every 16 days and harvested at 2 months after transplantation. On the other hand, essential oil yield peaked when irrigated every 8 days and harvested at 6 months. Thymol, p‐cymene, γ‐terpinene, and β‐caryophyllene were the major compounds, and they peaked at different irrigation intervals and harvest times. This study showed biomass, essential oil content, and yield as well as the major and minor constituents of Plectranthus amboinicus are influenced by irrigation interval and the timing of harvest.     

Energy aspects of the growth of Escherichia coli synchronized by starvation

The quantitative determination of adenyl nucleotides based on the separation of their dansyl derivatives by thin layer chromatography has made it possible to study the dynamics of changes in the pool of ATP, ADP and AMP in Escherichia coli K-12 during its synchronous growth after glucose starvation. The energy parameters (the adenylate pool, energy charge, teh ATP/ADP ratio, the rates of oxygen uptake and ATP generation, the economic coefficients of oxygen and ATP utilization) were compared with changes in the growth characteristics (the rate of growth and biomass concentration). This comparison allowed the authors to draw the conclusion about the uncoupled constructive and energy metabolism and about the possible regulatory role of energy parameters in the synchronised culture growth.     

Preparation and isolation of dansyladenylates as fluorescent substrates in reactions of the energy metabolism

A method was developed for preparation of dansylated derivatives of adenine nucleotides characterized by fluorescence when being irradiated with UV-light. The involvement of dansylated ATP, ADP and AMP as substrate analogues in energy metabolism is demonstrated in the ATPase, hexokinase, pyruvate kinase and adenylate kinase reactions. The kinetics of the reactions is discussed.     

Effect of bilirubin and serum albumin on the Na,K-ATPase activity in the synaptosomal membrane

The absorption spectrum of visible light, characteristic of the free bilirubin being in the aqueous medium, with a single maximum at 440 nm and with the shoulder in the region of 410-420 nm is transformed into the spectrum with two maxima in the region of 460 and 500 nm, respectively, when the pigment is bound in vitro by the synaptosomal membrane. There are two types of sites for bilirubin binding in the membrane particles, differing in the values of constants of association (Ka = 0.6 . 10(5) and approximately 2.02 . 10(5) M-1, respectively) and in the values of the maximum binding of bilidiene (5.0 and 7.0 nmoles/mg of membrane proteins, respectively). The binding of bilirubin by the synaptosomal membrane leads to a decrease in the specific activity of the membrane Na+,K+-ATPase. The enzyme activity is further decreasing when suspension of the membrane particles is exposed to the blue light (lambda max = 450-460 nm) in the presence of bilirubin. The addition of the serum albumin into the incubation medium potentiates the inhibition effect of bilirubin, when the suspension of membrane particles is lighted in the presence of bilirubin. The alkalization of the medium up to pH 7.8 (from pH 7.2) removes this potentiation effect of the addition of serum albumin.     

Effects of manganese on potassium outflow from erythrocytes and on respiration of rat liver mitochondria

In this work, effects of manganese on respiration of rat liver mitochondria and the rate of K⁺ outflow from rat erythrocytes are studied in a broad range of concentrations. It is shown that manganese ions at low concentrations (1 × 10^–7–3 × 10^–5 М) inhibit K⁺ outflow from rat erythrocytes; this can be used to prevent their lysis. At high concentrations (1 × 10^–4–1 × 10^–3 M), manganese activates K⁺ outflow from the erythrocytes but inhibits the valinomycin-induced outflow of the ion from the erythrocytes. This fact is an indication of manganese influence on physicochemical properties of membranes. At low concentrations manganese does not affect parameters of respiration and oxidative phosphorylation of rat liver mitochondria, while at high concentrations it exerts acceleration of the mitochondrial respiration, i.e., uncouples respiration from phosphorilation and, hence, inhibits ATP synthesis.     

The condition of the intestinal mucosa of the proximal digestive tract subjected sectioning of the jejunal wall]

The balance between secretion and degradation of the mucosa glycoproteins in the dog intestine is preserved with the aid of local reflexes in both serous-muscular and mucous-submucous layers of the wall. Irrespective of major alterations in the glycoproteins synthesis in the mucosa, protective properties of the submucous layer are maintained owing to a high content of acetylneuraminic acid and low level of mucous glycoproteins degradation.