Plant growth-regulating activities of batatasin III analogues

Nine bibenzyls and 10 stilbenes were synthesized as analoguesof batatasin III, a growth inhibitor isolated from dormant yambulbils, and examined for their plant growth-regulating activities.The bioassays used were the elongation of dark-grown intactrice coleoptiles, auxin-induced elongation of excised oat coleoptiles,and germination of rape and barnyard grass seeds. In the elongationof intact rice coleoptiles, 3,3'-dihydroxy-5-methoxy- (batatasinIII), 3,5-dimethoxy-3'-nitro-, 4'-bromo-3-nitro-, 3-amino-3'-chloro-,3-amino-4'-chloro-bibenzyls and 3-benzyloxy-4'-bromo-5-methoxy-,3-benzyloxy-3',4'-dichloro-5-methoxy-stilbenes were inhibitory,and 4'-bromo-3-nitrostilbene was promotive at a concentrationof 100 mg/liter. The results obtained by the other bioassayswere qualitatively consistent with these findings, although3-amino-4'- chlorobibenzyl and 4'-bromo-3-nitrostilbene werenot tested in all the bioassays. In the seed germination, which was rather tolerant to the testanalogues, batatasin III was inactive but 3-benzyloxy-4'-bromo-5-methoxy-and 3-benzyloxy-3',4'-dichloro- 5-methoxystilbenes were veryactive. Thus, if substituted properly, bibenzyls and stilbenes are activewithout hydroxyl and methoxyl group(s) as the functional group. ³ Present address: The National Institute for EnvironmentalStudies, Yatabc, Ibaraki 300-21, Japan. (Received November 19, 1975; )     

N-acetylchitosan gel: A polyhydrate of chitin

N-Acetylchitosan gel, a polyhydrate of chitin, and partially O-acetylated N-acetylchitosan gel were produced by a facile acetylation of chitosan with acetic anhydride in 10% acetic acid and in aqueous acetic acid/methanol at room temperature. Under the same conditions, a series of N-acylchitosan gels was produced in reaction with the other carboxylic anhydrides. The gels thus produced were colorless, transparent and rigid, and stable on heating. The gels were insoluble in cold and boiling water, formic acid, aqueous acids, and the other solvents examined. Significant changes in specific rotation occurred in the acylation of chitosan and its aggregation.     

Metabolism of PG in man: Effect of furosemide on the excretion of the main metabolite of PG F2α

The excretion rates of main urinary metabolite of PG F₂α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F₂α.     

Aurintricarboxilic acid as a probe for the analysis of chromatin structure.

Aurintricarboxylic acid is shown to cause nuclear swelling, disaggregation of chromatin structure and release of histones from chromatin. The nuclear swelling is inhibited by Ca⁺⁺ and Mg⁺⁺. The potential usefulness of aurintricarboxylic acid as a probe in chromatin studies is suggested.     

Studies on the subunits of myosin from muscle layer of Ascaris lumbricoides suum.

1. A purified preparation of Ascaris myosin was obtained from the muscle layer of Ascaris lumbricoides suum, using gel filtration and ion-exchange chromatography. 2. Ascaris myosin whether purified or unpurified, had almost the same ability for ATP-splitting and superprecipitation. 3. Ascaris myosin and rabbit skeletal myosin were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A significant difference in the number of light chains between both myosins was found. Ascaris myosin was found to have one heavy chain and two distinct light chain components (LC1-A and LC2-A), having molecular weights of 18000 and 16000, respectively. These light chains correspond in molecular weight to the light chain 2 (LC2-S) and light chain 3 (LC3-S) in rabbit skeletal myosin. 4. LC1-A could be liberated from the Ascaris myosin molecule reacted with 5,5'-dithio-bis(2-nirobenzoic acid( Nbs2) with recovery of ATPase activity by addition of dithiothreitol. These properties are equivalent to those of the LC2-S in rabbit skeletal myosin, although Ascaris myosin when treated with Nbs2-urea lost its ATPase activity.     

Anaerobic coryneforms isolated from human bone marrow and skin. Chemical, biochemical and serological studies and some of their biological activities.

Eighteen isolates if anaerobic coryneforms from human bone marrow and skin and four type strains of Propionibacterium were studied chemically, biochemically and antigenically. All of the isolates were identified as Propionibacterium acnes; of the 18 isolates,16 belonged to sterotype I and two to serotype II. By means of gas liquid chromatography and mass spectral analysis, a large amount of iso-type fatty acids, such as iso-pentadecanoic and iso-heptadecanoic acids were detected in whole cells of isolates and type strains. Antitumor and adjuvant effects of the isolates and type strains were found to differ considerably among the strains. One of the isolates, P. acnes C-7, which showed potent biological activities was fractionated by hot phenol-water extraction. The resulting insoluble middle layer was found the most effective in tumor protection, adjuvant action in immune response and phagocytic activity in mice.     

Single transient K channels in mammalian sensory neurons.

A single-channel recording of the transient outward current (A-current) was obtained from dorsal root ganglion cells in culture using patch-clamp techniques. Depolarization of the membrane patch elicited pulse like current of a uniform amplitude in an outward direction, of which the unitary conductance was 20 pS. Alteration of extracellular ionic compositions indicated that the charge carriers were K ions. A systematic study was made on the voltage-dependence of the ensemble average current; (a) the activation started at a potential around -60 mV; (b) the time course of the activation was relatively rapid; (c) the channel was completely inactivated at a potential positive to -40 mV. Two time constants (tau f = 100 ms and tau s = 4,000 ms) were detected in the decay of the current indicating that the channels had two different states of inactivation. A convulsant, 4-aminopyridine (4-AP), acted on the channel only from the intracellular side of the membrane. 4-AP (5 mM) reduced not only mean open time (by 50%) but also the single-channel conductance (by 20%). The properties of the channel were independent of Ca ions in the intracellular space.     

Repression of porin synthesis by salicylate in Escherichia coli, Klebsiella pneumoniae and Serratia marcescens

The synthesis of the OmpF porin in Escherichia coli K-12 was highly and reversibly inhibited by 5 mM salicylate in the bacterial growth medium, and salicylate also inhibited the OmpC porin synthesis, although only weakly. The full expression of the salicylate effect was presumed to require the ompB gene product on comparison between the wild type and ompB mutant strains. The salicylate effect was also observed for the porin protein synthesis in Klebsiella pneumoniae and Serratia marcescens, although an ompB-like gene remains to be identified in both species.