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Fumaric, palmitic, oleic and abscisic acids and methyl and ethyl hydrogen succinates were isolated from seedlings of dwarf pea (Pisum sativum L., var. Progress No. 9), grown under red light, as growth inhibitors which interfered with the responses of these plants to GA3. Of the six compounds, fumaric acid did not show any inhibitory effect on stem elongation in the absence of GA3.

The structures of seven new dimeric phenylpropanoids isolated from nutmeg, seed kernels of Myristica fragrans Houtt., were established. Two of them were phenylcoumarane derivatives containing a methylenedioxy group and the others were β-aryl ether-type compounds which had an allyl group attached to an aromatic ring.

Pre-emergent herbicidal activities of various 3-halo-6-phenoxypyridazines, with or without nitro groups on their benzene rings, and 3-anilino-6-phenoxypyridazines were examined along with those of related compounds. Among them, 3-bromo-6-(2′-phenylphenoxy)-, 3-chloro-6-(3′-nitrophenoxy)- and 3-chloro-6-anilino-pyridazines showed rather high herbicidal effects to radish and millet. On the other hand, some pyridazine derivatives especially 3-anilino-6-benzyloxy- and 3-(3′-chloroanilino)-6-phenoxy-pyridazines promoted shoot growth of millet.

Two novel gibberellins, GA21 (I) and GA22 (II), were isolated from immature seeds of sword bean, Canavalia gladiata DC. The isolation procedure of these substances as well as their growth-promoting effects on dwarf maize mutants d1 and d5, rice, cucumber and dwarf peas (Progress No. 9) are described.The structures of two new gibberellins, GA21 and GA22, isolated from immature seeds of sword bean, were determined as 4aα, 7α-dihydroxy-8-methylenegibbane-1, 1, 10β-tricarboxylic acid 1→4a lactone (II) and 4aα, 7α-dihydroxy-l β-hydroxymethyl-8-methylenegibb-2-ene-1α, 10β-dicaboxylic acid 1→4a lactone (IV), respectively, on the basis of chemical and physicochemical studies.

A new biologically active substance named fragin was isolated from cultured broth of a bacterial strain, which was identified as Pseudomonas fragi based on taxonomic study. Isolation, characterization and biological activities are described in detail.

The structures of ezomycins A1. and A2, antifungal antibiotics produced by a strain of Streptomyces, were determined as 1 and 2, respectively, by degradative and spectrometric studies.

It has been confirmed that gibberellin A is a mixture of three components, gibberellin A1, gibberellin A2 and gibberellic acid (namely gibberellin X), by treating their methyl ester through the chromatography on A12O3 column. Attempts to separate them in free acid were made. The physical and chemical properties of each gibberellin as well as its physiological properties are described

Piericidin B was isolated from mycellia of Streptomyces mobaraensis besides piericidin A. On the basis of IR, NMR and mass spectral studies together with chemical evidences, its structure was assigned as Id. Its physiological activities are also deescribd.

The elongation of the second leaf sheaths of rice seedlings was promoted strongly by helminthosporol as well as by gibberellic acid. A greater dosage of helminthosporol was required in order to induce the same amount of elongation. Cells of treated plants were somewhat longer than those of controls. The elongation of the second leaf sheath was caused mainly by an increase in cell number. Both helminthosporol and gibberellic acid promoted the elongation of cells in the basal portion of the second leaf sheath.

Stress relaxation mechanisms were investigated on three types of (EPDM) ethylene-propylene terpolymers in air at 109° C. These polymers differ only by the structure of the crosslinkage in which there is a carbon-carbon bond, a polysulfide linkage −Sx⁁− or a monosulfide linkage (—S—). All the stress relaxation of peroxide-cured EPDM polymer was not due to the oxygen-induced cleavage of the main chain but to a physical flow. In the case of sulfur-cured EPDM polymer, the relaxation curve is divided into three straight lines when the procedure X is used and log f(t)/f(0( is plotted linearly with time. It was concluded that this graph was in agreement with an interchange reaction of the polysulfide linkage by an oxidative cleavage of the monosulfide linkage. On the other hand, a TT-cured EPDM polymer gave a plot with a straight line. This stress relaxation could be explained by an oxidative cleavage of the monosulfide linkage.

Series of phenoxypyrimidines and phenoxytriazines were prepared to be evaluated as herbicides. Among them, 2-(2,6-dichlorophenoxy)-pyrimidine (XV), 2-phenoxy-4,6-dimethyl- pyrimidine (XVII), 2-(3-methyl-4-chlorophenoxy)-4,6-bis(ethylamino)-5-triazine (LIV), 2-(2,4-dichlorophenoxy)-4,6-bis(ethylamino)-s-triazine (LVIII), and 2-(2,6-dichlorophenoxy)-4,6-bis(ethylamino)-s-triazine (LX) showed high pre-emergent herbicidai activity to radish. On the other hand, 2-chloro-4-(2,6-dichlorophenoxy)-6-methylpyrimidine (XXX) revealed high efficiency to millet. Some structure-activity relationship is discussed.

To confirm the location of the lactone ring at ring A of gihberellin A3, selenium de-hydrogenation experiments were conducted in various ways. The results thus obtained and NMR spectrum studies rather support structure (III).

Various O,O-dialkyl O-cyanophenyl phosphates and phosphorothioates were prepared and their biological activities were examined. Among them, O,O-dimethyl O- (4-chloro-2-cyanophenyl) phosphorothioate was found to have selective and high toxicity to houseflies. O,O-Dimethyl O- (4-cyanophenyl) phosphorothioate, O,O-diethyl O- (4-cyanophenyl) phosphorothioate and O,O-diethyl O- (2-chloro-4-cyanophenyl) phosphorothioate showed high insecticidal activty to American cockroaches, though the former two were not so effective to houseflies. The dimethyl esters of these series exhibited markedly lowered mammalian toxicity. Among the O-ethyl O-cyanophenyl phenylphosphonothioates, O-ethyl O- (2-chloro-4-cyanophenyl) phenylphosphonothioate was highly effective to mites, while less effective to insects.

In the previous paper(1)(2) it was reported that some of the ω, ω'-bis-(3, 4-dihydroxyphenyl) alkanes showed remarkable antioxidant activites equal or superior to that of NDGA. Therefore, in the present paper syntheses of ω, ω'-bis-(3, 4-dihydroxyphenyl) butane and hexane were exa-mined from the practical standpoint. (1) the preparation of 1, 4-bis-(3, 4-dihydroxyphenyl) butane. The. synthetic method of ω, ω'-bis-(3, 4-dihydroxyphenyl) butane described in the previous paper(3) was so complicated that the examination of alternative processes seemed to be necessary. Firstly, ω-bromoacetoveratrone was treated with aqueous KOH in ethanol to yield 1, 2-diverat-roylethylene according to the BOGOSLOVSKII's method(4), but this attempt was unsuccessful. Then, the method of LUTL(7) to give 1, 2-dibenzoylethylene by the condensation/of benzene and fumaryl chloride was applied for veratrol but the corresponding dibenzoylethylene was not obtained. Next, in order to prepare 1, 4-diveratrylbutane via 1, 2-diveratroylethane, ω-bromoace-toveratrone was converted into car-cyanoacetoveratrone, m.p. 137_??_138° and the both compounds were condensed to give 1-cyano-1, 2-diveratroylethane, m.p. 148_??_149°, but the yield of the first step was so low such as 36% that this method should also be given up. Finaly, the processes from vsratrol and succinic anhydride to yield 1, 4-diveratrylbutane reported in the previous paper(3) were re-examined and the following results were obtained. The yield of 1-veratroyl-3-(3.4-dimethoxy-6-bromophenyl) propane from γ-(3, 4-dimethoxy-6-bromophenyl) butyric acid was found to increase from 13% to 60% when the chloroform solution of the latter compound was treated with SOCl2 in the presence of a trace of-dry pyridine. Then, 1, 4-diveratrylbutane was obtained in 90% yield by hydrogenating 1-veratryl-4-(3, 4-dimethoxy-6-bromophenyl) butane with Raney Ni and KOH in ethanol at 12 atm. and 63°. (2) The preparation of 1, 6-bis-(3, 4-dihydroxyphenyl) hexane. In this series, the ruduction of 1, 4-diveratroylbutane was found to be the most difficult step as was described in the previous paper(3) but it was solved by the following method. 1, 4-Di-veratroylbutane was hydrogenated to give 1, 6-diveratrylhexane with Pd-charcoal in ethanol-acetic acid at atmospheric pressure and room temperature., in the theoretical yield. Also with Cu-CrO in ethanol at 160° for 4 hrs with an initial pressure 40 atm. in 70% yield. 1, 6-Bis-(3, 4-dihydroxyphenyl) hexane was obtained by refluting 1, 6-diveratrylhexane with powdered AlCl3 in anhydrous chlorobenzene for 4 hrs at 140_??_150°. The authors wish to express their appreciation to Professor Dr. Y. SUMIKI for his guidance and advice

The mass spectra of the destruxins, insecticidal cyclodepsipeptides, were examined. The major ion peaks at [M – 57], [M – 85], [M – 142] and [M – 170] observed in the spectra were proved to be characteristic of the presence of the N-methylvalyl-N-methylalanyl moiety in the ring structure. The amino acid sequence in the destruxins was confirmed through the analyses of the mass spectra of their open-chain derivatives.

カイコを被検昆虫として,経口投与により薬用植物中の昆虫生理活性物質を検索する過程で,次のことが明らかになった. (1) 漢方薬ニクズク末がカイコ幼虫の成育を阻害し,ある場合には三眠蚕を出現させた. (2) このような成育阻害活性をもたらすものとして,ニクズク末より単離されたghenylpropanoidsならびに,それらの関連物質のカイコの成育に対する影響をしらべたところ,メチレンジオキシ基や,多数のメトキシル基を持つ化合物が,顕著な阻害活性を示した. (3) これらのphenylpropanoidsのうち,化合物IIIは50ppmで4令カイコ幼虫に対して摂食阻害的作用を示し,化合物Vは100ppmで4令カイコ幼虫に対して毒物的作用をあらわし, 90%致死させた.

In connection with the evaluation of polymer stability and chemical antioxidants it is a very urgent work to make clear the degradation mechanism of crosslinked polymers.There have long been two extremely different opinions about the mechanism of scission of network chain polymers, especially about natural rubber vulcanizates. One is that only random chain scission of this vulcanizates occurs in the oxidation reaction from the experiments and theory by A. V. Tobolsky. Another is that only their crosslink scission occurs in the oxidation reaction from the experiments and theory by Berry and Watson.The results of recent studies of crosslinked polymers including this vulcanizates show that both the scissions may occur at the some time in many cases.So the authors have made an attempt to derive the general equations for both the scissions for the purpose of finding out the quantitative amounts of scission chains using the experimental results and judging the relative estimation of the scissions.We have generalized the case where one cross-linkage is cut in the minimum model of perfect chain network, and the following equation has been derived for the vulcanizates in which both the scissions occur.Nt/N0=ft/f0={1-4kx/k+2x·Q(t)/M0}·e-2x2/k+2x·Q(t)/M0+2kx/k+2x·Q(t)/M0·e-4x2/k+2x·Q(t)/M0(1)The Eq. (1) in both the cases of k→0 and k→∞, conforms to that proposed by Tobolsky. Assuming the more practically probable mechanism in the scission of cross-linked polymer, the following Eq. (2) obtained by modification of Eq. (1) is derived.Nt/N0=ft/f0={1-8kx/k+2x·Q(t)/M0}·e-2x2/k+2x·Q(t)/M0+6kx/k+2x·Q(t)/M0·e-4x2/k+2x·Q(t)/M0-2kx/k+2x·Q(t)/M0·e-8x2/k+2x·Q(t)/M0(2)The theoretical relation between Q(t)/M0 and Nt/N0 is shown and discussed.

Tenuazonic acid has been isolated as a halo-inducing toxin from the culture filtrate of Alternaria longipes, a fungus causative of the tobacco brown-spot disease. Further, its occurrence in leaves of diseased plants was confirmed by a spectrometric method. The role of the acid in the host-parasite interaction was elucidated from the phytopathological standpoint.

Fragin (I) was synthesized as the racemate by use of isobutyryl chloride or isobutyl-aldehyde as a starting material.

Stress relaxation mechanisms were investigated for various curing systems in natural rubber, especially the ‘complex’ crosslinking irradiation cure systems containing sulphur or tetramethylthiuram disulphide (TMTD) in both air and nitrogen mainly at 100°C. With the systems, the chemical stress relaxation in air showed that in the main oxidative scission was the major cause of stress decay. However, the number of moles of main chain scission, qm(t) seemed to be dependent on the chemical structure of the crosslink. In the TMTD curing system and irradiation-TMTD curing systems, qm(t) is independent of the ratio, ρ, of the effective chain density Nc(0) based on the carbon-carbon crosslinkages to Nm(0) based on mono- and di-sulphide linkages. Stress decay in air of both accelerated-sulphur cures and irradiation-sulphur cures was shown to be due to both the interchange reaction of polysulphide linkages and random scission of the main chain. On the other hand, in nitrogen there are two simultaneous reactions at the crosslink:interchange and thermal scission.

Effects of helminthosporol and helminthosporic acid (H-acid) on nicotine biosynthesis in Nicotiana were examined. By the addition of these compounds into nutrient solution, nicotine formation in decapitated and intact plants of Nicotiana tabacum was decreased. In sterile culture of excised roots of Nicotiana rustica, H-acid reduced the yield of nicotine exerting no effect on growth rate. Incorporation of l-glutamic acid-U-14C and dl-ornithine-2-14C into nicotine in the roots was decreased by the addition of H-acid, and that of nicotinic acid-3H(G) was not influenced. Since H-acid did not enhance destruction of nicotine-3H exogenously added, it is probable that the decrease of nicotine yield by the acid in the root culture is due to reduction in the production rate of the alkaloid.

Absolute configurations of C–2 and C–3 in “Acid III” (IIa), a degradation product of piericidin A diacetate, was determined as R and S, respectively. Consequently both C–9 and C–10 in piericidin A were confirmed to have S configurations. On the basis of UV and NMR specta, configurations of the double bonds in piericidin A were assigned as shown in Ia.

Seven gibberellin glucosides (F-I_??_F-VII) were isolated from immature seeds of Japanese morning-glory (Pharbitis nil). The structures were elucidated as 2-O-β-glucosyl-gibberellin A3 (F-I), 2-O-β-glucosyl-gibberellenic acid (F-II), 2-O-β-glucosyl-isogibberellin A3 (F-III), 3-O-β-glucosyl-gibberellin A26 (F-IV), 3-O-β-glucosyl-gibberellin A27 (F-VI) and 3-O-β-glucosyl-gibberellin A29 (F-VII). The one of the glucosides (F-V) was identified as 3-O-β-glucosyl-gibberellin As isolated from Phaseolus multiflorus.

The outline of this report has already been published in this Journal as a communication to the Editors. The relation among four isomers, gibberellin A1, gibberellin C, pseudogibberellin A1 and isogibberellin A1 was clarified. The partial structure of gibberellin C is presented.

Both initial network chain densities nM(0) and nS(0) of dicumyl peroxide- cured natural rubbers were determined from the tensile stress and swelling method, respectively. The difference between nM(0) and nS(0) was usually constant, independent of the magnitude of network chain density. That is, it was found that the number of entanglement network chains in the crosslinked natural rubber was usually constant, independent of network chain density. The entanglement network chain density nII(0) was 0.7×10−4 mole/cc. This led to the supposition that the molecular weight between entanglement points Me would be about 9000. Although this value is far from exact, it does not differ too greatly from the value found for noncrosslinked natural rubber. Next, in order to calculate the number of main-chain scissions of crosslinked polymers from their chemical stress relaxation, we proposed our modification of Tobolsky's equation. Using our equation, it was found that the scission of dicumyl peroxide-cured natural rubber occurred in the main chain only. Furthermore, this value agreed with the one obtained from the oxidation of toluene solution of noncrosslinked rubber under the same conditions.