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The total synthesis of surfactin B2, a cyclic depsipeptide isolated from Bacillus natto KMD 2311, was achieved to elucidate the absolute configuration of its fatty acid moiety. This is the first chemical confirmation of the absolute configuration of a surfactin homolog. Two possible diastereoisomers of surfactin B2, cyclo[D- and L-3-(Glu-Leu-D-Leu-Val-Asp-D-Leu-Leu-O)-n-tetradecanoyl] (1a and b), were synthesized by a solution method using mainly active ester and azide fragment condensation methods. Cyclization reaction of the partially protected linear depsipeptide containing the C-terminal N-succinimidyl active ester in pyridine by the high dilution method at room temperature for 3d gave the desired cyclic depsipeptide in a high yield of about 70%. The synthetic product 1a, containing the D-isomer of 3-hydroxytetradecanoic acid as a fatty acid moiety, was identical with natural surfactin B2.

Crude surfactin was simply prepared from the culture filtrate of Bacillus natto KMD 2311 twice by acidification of the filtrate and extraction of the precipitate with ethanol. Eight surfactin analogs were isolated from the crude surfactin by RP-HPLC and gel filtration. The structure of each analog was deduced by means of amino acid composition of the acid hydrolysate and FAB-MS measurement to be a cyclic depsipeptide containing a hydroxyfatty acid. The structure of the hydroxyfatty acid moieties was elucidated as n- or iso- or anteiso-3-hydroxyfatty acid composed of carbon number 13-16 by GC analysis and EI-MS after the methanolysis of the analogs. The amino acid sequence of the peptide portion was assigned as acyl-Glu-Leu-Leu-Val-Asp-Leu-Leu by EI-MS for eight analogs. The isolated four compounds were found to be identical with the known surfactin analogs, A1, B1, B2 and C1. Although surfactin A2 and C2 had not been isolated, their structures were deduced to be a surfactin analog. Surfactin A3 and D were novel analogs. The acyl groups of surfactin A2, A3, C2 and D were anteiso-3-hydroxytridecanoic acid, n-3-hydroxytridecanoic acid, anteiso-3-hydroxypentadecanoic acid and iso-3-hydroxyhexadecanoic acid, respectively.

ortho-Directed lithiation of a number of (2-methoxy) ethoxy- and (2-dimethylamino) ethoxyarenes has been investigated. Lithiation of these compounds followed by treatment with various electrophiles afforded ortho-substituted products in moderate to excellent yields.

The efficient catalytic action of polyphosphoric acid, when used in the presence of suitable nucleophiles, of both normal and abnormal ring opening of 4β,5-epoxy-5β-cholestan-3-one (I) is reported. In acetic acid, I affords 2α-acetoxycholest-4-en-3-one (XIIa; abnormal product) whilst, in marked contrast, ethanethiol reacts with I in dioxane affording 4-thylthiocholest-4-en-3-one (XV; normal product) and a further product, 3,4-bis-(ethylthio)cholesta-3,5-diene (XVI). Ethanedithiol and β-mercaptoethanol react with I, as expected, affording cholesta-3,5-dieno[3,4-b]dithiane (XVII) and its oxathiane derivative (XIX) respectively. The nature of the reactions is briefly discussed and presence of some unique conjugation in the SC 3 S and OC 3 C 4 S systems in the dithiane (XVII) and oxathiane (XIX) is suggested on the basis of their UV absorption data.

Heating of pyrrolizidine N-oxide (V) with an aqueous solution of tartaric acid containing ferric nitrate gave Δ1 (8)-dehydropyrrolizidine (VI), which, on treatment with water in the presence of methyl iodide, gave 1-methyl-perhydroazocin-5-one (IX).

The nature of all six oxygen atoms in enmein, C20H26 (28)O6, were clarified as two of hydroxyls, one of inert ketone, and one of methylene ether ester of hydroxy acid. The discovery of a new group, methylene ether ester of hydroxy acid [chemical formula] seemed of great interest.

In order to study the structure-activity relationship of sparsomycin, an antitumor antibiotic, 26 sparsomycin analogs (3-5) were synthesized and their antibacterial activities and lytic actions on Ehrlich ascites carcinoma cells were tested. It was found that N-[(E)-β-(6-methyluracil-5-yl) acryloyl]-S-methyl-D-cysteinol (5g) and N-[(E)-β-(6-methyluracil-5-yl) acryloyl]-D-methioninol (5i) showed significant antibacterial activity (minimum inhibitory concentration 25 μg/ml) against Streptococcus pyogenes.

For the purpose of finding out a strain which has stronger cytolytic activity on Ehrlich ascites carcinoma cells, the authors isolated 113 strains of Bacillus natto from straws, which were collected at various areas in Japan, and measured the cytolytic activities by cylinder plate method. As the results, the authors found out a strain of Bacillus natto (tentatively called KMD 2311) which has the strongest cytolytic activity in the 113 strains. There were at least two kind of cytolytic substances on Ehrlich ascites carcinoma cells in the culture medium of Bacillus natto KMD 2311. One was extracted with AcOEt from the culture medium, which constitute approximately 20% of the cytolytic activity in the culture medium and it was stable. This cytolytic substance was purified and colorless crystalline compound (mp 247-249°) was obtained by recrystallization from acetone-petr. ether. Chemical structure of this compound was examined by elementary analysis, infrared, nuclear magnetic resonance, and mass spectroscopy and study of decomposed products. As the results, this compound was proved to be identical with surfactin (mp 140°), which was obtained from culture medium of Bacillus subtilis by Kakinuma, et al. and from Bacillus natto KMD 1126 by the authors. Melting point of this compound (mp 249°) was higher about 100° than that of surfactin (mp 140°), but high mp compound was obtained from surfactin by recrystallization from acetone-petr. ether. From these results, it was indicated that the cytolytic substance was identified with surfactin and dimorphic.

Heating of pyrrolizidine N-oxide (V) with an aqueous solution of tartaric acid containing ferric nitrate gave Δ1 (8)-dehydropyrrolizidine (VI), which, on treatment with water in the presence of methyl iodide, gave 1-methyl-perhydroazocin-5-one (IX).

ortho-Directed lithiation of a number of (2-methoxy) ethoxy- and (2-dimethylamino) ethoxyarenes has been investigated. Lithiation of these compounds followed by treatment with various electrophiles afforded ortho-substituted products in moderate to excellent yields.

Five sparsomycin analogs (9-13) were prepared and examined for their ability to inhibit deoxyribonucleic acid (DNA) synthesis in L5178Y lymphoma cells. All of the compounds showed significant activity in the DNA synthesis assay. The compounds having RC configuration exhibited almost the same activities independently of the configuration at the sulfoxide sulfur atom. Among the SC isomers, the RS configuration was advantageous for the appearance of activity.

The acylase of Ehrlich ascites carcinoma cells was purified by fractionation with ammonium sulfate, diethylaminoethyl cellulose chromatography, Sephadex. G-200 gel filtration, and hydroxylapatite chromatography. The acylase activity of the purified enzyme toward N-dichloroacetyl-L-aspartic acid was 1561 U/mg and it was represented about 410 fold purification over the cell free extract. The enzyme has a pH optimum around 8.5 toward N-dichloroacetyl-L-aspartic acid. It is inhibited by Sn2+, Mn2+, Cu2+, Hg2+, Zn2+, p-chloromercuribenzoate, ICH2COOH, H2O2, and diisopropyl fluorophosphate. As a result of the investigation of substrate specificity, it was found that the enzyme hydrolyzed only N-dichloroacetyl-L-aspartic acid among eleven kinds of N-dichloroacetyl amino acids. But it could not hydrolyze D from of N-dichloroacetyl-aspartic acid. In order to test the effect of acyl groups toward the enzyme activity, eleven acyl aspartic acids were tested. N-Chloroacetyl, N-dichloroacetyl, N-trifluoroacetyl derivatives of L-aspartic acid were hydrolyzed.

Synthese et etude biologique des composes du titre N-substitues par carboxy-1'-, methoxycarbonyl-1'- ou hydroxymethyl-1' alkyl, la partie pyrimidine etant elle-meme substituee par dimethoxy-2,4 methyl-6 ou dioxo-1,3 tetrahydro-1,2,3,4 trimethyl-1,3,6