A Total Synthesis of (±)-Pachyrrhizone

We examined whether developing cotyledons of soybean seed had photosynthetic activities. The cotyledons evolved oxygen under illumination and the activity was inhibited by 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea. The rate of oxygen evolution decreased during the development of seeds; about 30μ miol O₂ · mg chlorophyll^-1 · hr^-1 at the early developing stage and about 10μ miol O₂-mg chlorophyll^-1 · hr^-1 at the late developing stage. The rate of oxygen uptake remained at an almost constant level of 40^mol 0₂-mg chlorophyll^-1 · hr^-1 throughout the development. Photosynthetic ¹⁴CO₂-fixation by the cotyledon was observed. Ribulose bisphosphate carboxylase was immunochemically detected in the developing cotyledons. These results show that functional photosynthetic apparatus is present in the developing cotyledons of soybean seeds.     

Total Synthesis of (±)-Millettone

(±)-Millettone (14) was synthesized.     

Synthesis of (±)-Tubaic Acid

An alternative synthesis of (±)-tubaic acid (I), a key intermediate compound of rotenone synthesis, has been accomplished by the Wittig reaction.     

A Simple Total Synthesis of (±)-(δ-Cadinene

This paper reports on a total synthesis of racemic δ-cadinene (2), which had been obtained previously in optically active form by acid-catalyzed cyclization of (–)-germacrene D. The Robinson annelation using cyclohexenone enamine (12) proceeded stereoselectively to form δ-cadinenone (3), whose oxygen was removed by the thioketal–Raney Ni method to produce δ-cadinene.     

A Total Synthesis of (±)-Gibberellin A12 via Methyl (±)-7,16-dioxo-17-norkauran-19-oate

¹⁴C-labelled methionine, xanthosine, and 7-methylxan-thosine were given to excised tea shoots. The methyl group of methionine was incorporated into 7-methylxanthosine (ca. 10%) in the earlier period of incubation after the uptake. About 50% of the radioactivity of xanthosine was rapidly incorporated into caffeine via 7-methylxanthosine, 7-methylxanthine, and theobromine within 24 hr. 7-Methylxanthosine was also converted into caffeine at a high rate. The results suggest that the pathway for caffeine biosynthesis is as follows: xanthosine → 7-methylxanthosine → 7-methylxanthine → theobromine → caffeine.     

Synthesis and Biological Activities of (±)-Deoxy-abscisic Acid Isomers

Phosphodiesterase production with bis-p-nitrophenyl phosphate as a substrate by alkalophilic Bacillus No. A-40-2 increased with increasing Mn²⁺ concentration, showing maximum productivity at 10 mm. The enzyme production was negligible in the medium without Mn²⁺. The simultaneous addition of 10 mm Mn²⁺ and one of the several cations Mg²⁺, Co²⁺, Mo⁶⁺, and Pb²⁺ at suitable concentrations stimulated the enzyme production 1.8-fold at most over that with only 10 mm Mn²⁺. Inorganic phosphate hardly repressed the enzyme production. The enzyme was purified homogeneously. The purified enzyme had the optimum pH of 7.5 and was fairly stable from pH 7–11. The enzyme hydrolyzed 2′,3′-cyclic-nucleotides and 3′-nucleotides, but did not hydrolyze 3′,5′-cyclic-nucleotides or 5′-nucleotides, indicating it to be a 2′,3′-cyclic-nucleotide 2′-phosphodiesterase (EC 3.1.4.16). The enzyme had activity without metals, but Mg²⁺, Ca²⁺, Ba²⁺, and Mo⁶⁺ activated the enzyme reaction.     

Synthesis of (±)-Deguelin

Total synthesis of (±)-deguelin was described. Thermal rearrangement of 1,1-dimethyl-2-propynyl ethers of β-resorcinaldehyde and 2,3-dimethoxy-9-hydroxy-rotoxen-12(6H)-one afforded β-tubaaldehyde and dehydrodeguelin respectively. 2,2-Dimethyl-5-hydroxybenzopyran-6-yl 3-(3,4-dimethoxyphenoxy)-1-propynyl ketone was converted to the corresponding benzopyran-6-yl benzopyran-4-yl ketone, which was treated with sodium acetate to give (±)-deguelin.     

Synthesis of (±)-licarin-B

The synthesis of (±)-licarin-B, a neolignan of Licaria aritu Ducke (Lauraceae), was achieved by pyrolysis of 3-hydroxy-3-piperonyl-1-propyl-2-methoxy-4-(E)-propenylphenyl ethers.     

Synthesis of Isochroman-1,3-diones A New Synthesis of (±)Sclerin

(±)Sclerin (4,5,6,7-tetramethyl-8-hydroxyisochroman-1,3-dione), a mycerial extracts of Sclerotinia libertiana, and related compounds were synthesized. Alkylated-7-hydroxyindanones were obtained from alkylated phenols and α-bromobutyrylbromide, and these indanone derivatives were treated with benzaldehyde to give 2-benzylidene-7-hydroxyindanone derivatives. By ozonolysis of these benzylidene-indanones were obtained 8-hydroxyisochroman-1,3-diones.     

Synthesis of (±)-Hydroxytremetone

(±)Hydroxytremetone (III) has been synthesized from 2-(α-hydoxyisopropyl)-6-hydroxycoumaran (V b) via its O-acetate V c by dehydration with phosphorus tribromide in pyridine solution, followed by acylation with a mixture of trifluoroacetic anhydride and acetic acid. Isohydroxytremetone (IX b) was also synthesized.     

Synthesis of (±)-Xanthoxins

The enzymatic properties of P2-2 enzyme were determined by using cells of M. radiodurans. The enzyme was: most active at 60°C incubation temperature, stable at 40°C in neutral buffer, and inactivated by heating at 80°C for 15min. Maximal lytic activity occurred at pH 8.5 in Tris-HCl buffer. The range of enzyme stability was between pH 5.5 and 8. Bivalent metal ions, p-chloromercuribenzoate and monoiodo acetate inhibited lytic activity. The molecular weight was estimated to be 16,000 daltons by gel filtration on Sephadex G-75. The enzymatic digestion of peptidoglycans from the cell walls of M. radiodurans and M. lysodeikticus liberated free amino groups, but neither reducing groups nor N-acetylhexosamine, indicating that the enzyme was an endopeptidase. From analysis of the N-terminal amino acids of the digests, it is suggested that the P2-2 enzyme cleaves the peptide bond at the carboxyl group of D-alanine in peptidoglycan.     

Synthesis of (±)-Homosarkomycin and (±)-Rosaprostol

(±)-Homosarkomycin (2) and (±)-rosaprostol (3) were synthesized from (±)-methyl 2-oxo-bicyclo[3.1.0]hexane-1-carboxylate (1) by using the nucleophilic ring opening reaction on the double-activated cyclopropane ring as the key step.     

Synthesis of (±)-Lamprolobine and (±)-Epilamprolobine

(±)-Lamprolobine, the (+)-enatiomer of which was isolated from the leaves of Lamprolobium fruticosum, and (±)-epilamprolobine were synthesized from δ-valerolactam.     

Total Synthesis of (±)-Sermundone and An Alternative Cyclization Method to Dehydrorotenoids

(±)-Sermundone (2), one of the hydroxyrotenoids, has been synthesized. Also a new cyclization method to dehydrorotenoids has been developed using alkali metal salts.     

A Novel Synthesis of (±)-Munduserone via Acetylenic Intermediates

A riboflavin α-glucoside-synthesizing enzyme from the acetone powder of pig liver was purified by a procedure including fractionation with ammonium sulfate, heat treatment, fractionation with acetone, gel filtration on a Sephadex G-150 column, calcium phosphate gel treatment, and isoelectric focusing. A final enzyme preparation was homogeneous on polyacrylamide disc gel electrophoresis and in the ultracentrifuge. The enzyme had a sedimentation coefficient of 9.90 S and an isoelectric point of pH 3.7. The enzyme had a pH optimum at 6.0 with maltose as substrate. The enzyme catalyzed the hydrolysis of diverse kinds of α-glucosidic substrates, and the transfer of α-glucosyl residue from these substrates to riboflavin. The Km value for maltose was 1.20×10^?3m. The enzyme hydrolyzed phenyl α-maltoside to glucose and phenyl α-glucoside. Amylose was almost completely hydrolyzed to glucose by the enzyme. Maltotriose was obtained as the main transfer product after the treatment of maltose with the enzyme. The enzyme also catalyzed the transfer of α-glucosyl residue from maltose to pyridoxine, esculin, rutin, and adenosine. It was recognized that a single enzyme catalyzed not only the hydrolysis of maltose and α-glucosidic substrates but also the transfer of the α-glucosyl residue of these substrates to suitable acceptors.     

A Novel Synthesis of (±)-Munduserone via Acetylenic Intermediates

A new synthetic route of rotenoids was developed and (±)-munduserone (15) was synthesized from acetylenic ketone (11).