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Objectives: We investigated the time course of the stromal cell-derived factor 1α (SDF1α) expression and behavior of intravenously administered bone marrow-derived stromal (BMS) cells in the urinary bladder of partial bladder outlet obstruction (PBOO) rats. Methods: Study 1: Recombinant SDF1α or saline was directly injected into the bladder wall of female rats followed by intravenous administration of BMS cells isolated from green fluorescent protein (GFP) transgenic rats. The bladder was examined with immunohistochemistry to determine whether SDF1α would enhance migration of BMS cells to the bladder. Study 2: Following surgery of PBOO or sham in female rats, bladders were removed on days 1–14, and expression of hypoxia inducible factor 1α (HIF1α) and SDF1α were examined with real-time polymerase chain reaction (PCR) to determine if PBOO preferentially increased their expression. Study 3: Female rats underwent PBOO or sham surgery followed by intravenous administration of GFP-positive BMS cells. Bladders were examined with immunohistochemistry on days 1–14 to determine whether BMS cells preferentially accumulated in the bladder. Results: BMS cells were accumulated in the injection site of SDF1α but not saline in the bladder. SDF1α and HIF1α increased at day 1 after PBOO compared to sham. More BMS cells accumulated in the bladder of PBOO on day 1, and some BMS cells expressed smooth muscle phenotypes by day 14. Conclusion: SDF1α induced with ischemia/hypoxia due to PBOO is implicated in the accumulation of BMS cells in the bladder and regeneration of the bladder for PBOO.

ATPase associated with various cellular activities (AAA) proteins are commonly distributed among eukaryotes, and are involved in a multitude of cellular functions. NtAAA1 is one such example, being involved in pathogen response in tobacco plants. When its activity was suppressed in RNAi transgenic tobacco plants, an elevated resistance to the pathogenic bacterium Pseudomonas syringae was observed in comparison with the wild type. As AAA proteins function through interaction with specific partners, NtAAA1-interacting proteins were screened by the yeast two-hybrid assay, and one particular gene encoding a small GTPase, an ADP ribosylation factor, was identified and designated as NtARF. Its specific binding to NtAAA1 was confirmed by in vitro pull-down assay, and their interaction was predominant between active forms of NtARF and NtAAA1, each bound to GTP and ATP, respectively. Their physical interaction in vivo around the plasma membrane was shown by fluorescence resonance energy transfer assays, suggesting their role in membrane trafficking. Transgenic tobacco plants constitutively expressing NtARF under the control of a cauliflower mosaic virus 35S promoter exhibited spontaneous and wound-induced lesion formation, and enhanced resistance to pathogen attack. Expression of NtAAA1 in leaves of NtARF transgenic plants attenuated lesion and suppressed pathogen resistance. In wild-type tobacco plants, transcripts of NtAAA1 and NtARF could be induced by ethylene and salicylic acid, respectively. These results suggest that NtAAA1 balances plant resistance through suppression of NtARF, and that the molecular basis for the known antagonistic actions of ethylene and salicylic acid in defense response could be partly attributable to these two proteins.

OBJECTIVE To characterize serial long-term histological changes in mesenchymal cells infiltrating a collagen-based matrix, as in a hollow organ with differentiated urothelial lining created intraperitoneally by grafting cultured urothelial cells, mesenchymal cells with smooth-muscle immunohistochemical characteristics infiltrated into the scaffold, despite no mesenchymal cells being seeded into the scaffold before grafting. MATERIALS AND METHODS To regenerate a urothelial lining tissue intraperitoneally, rat urothelial cells were cultured and seeded with the feeder-layer technique onto bladder acellular matrix (BAM). After 7 days of cultivation to attach urothelial cells on the BAM, the matrix was folded with the urothelial cells inside and grafted onto the mesentery of the previously partially cystectomized rat. RESULTS The grafted urothelial cells on the BAM, which formed a monolayer before grafting, stratified into three to four layers as early as 4 days after grafting. Although the regenerated urothelium became thinner with time, there was urothelial stratification and a peculiar angular appearance on the apical surface of the regenerated urothelium even after 56 days. The mesenchymal cells infiltrating the BAM showed positive immunohistochemical staining to α-smooth muscle actin or desmin at 7 days. Subsequently, the number of actin- or desmin-positive cells gradually decreased with time. On transmission electron microscopy, the infiltrating mesenchymal cells were characterized as myofibroblasts at 7 days. Smooth muscle-like cells were identified at 14 and 28 days, and fibrocytes were the main population at 56 days. CONCLUSIONS Although epithelial-mesenchymal interactions have been assumed to be one of the most critical factors in smooth-muscle development, mesenchymal cells infiltrating the scaffold in this intraperitoneal regeneration model gradually lost smooth muscle characteristics with time. These results suggest that interactions between cultured urothelial cells and infiltrating mesenchymal cells alone could not maintain the smooth muscle character of infiltrating mesenchymal cells.

Heavy metals are potentially highly toxic for organisms. Plants possess the ability to minimize damage but the underlying molecular mechanisms have yet to be detailed. Screening Cd-responsive genes in Arabidopsis, we previously identified a gene encoding a putative metal binding protein CdI19, which, upon introduction into yeast cells, conferred marked toleration of Cd exposure. Here we describe that bacterially expressed CdI19 directly interacts with Cd at its CXXC motif, as revealed by circular dichroism analysis, and that it is exclusively localized at plasma membranes, as revealed by heterologous expression of fusion product with a green fluorescent protein in BY2 cells. Northern blot analyses indicated that CdI19 transcripts were induced not only by Cd, but also by dicationic forms of Hg, Fe and Cu. Histochemical assays using transgenic Arabidopsis expressing the CdI19 promoter::GUS showed CdI19 to be expressed in petiole, hypocotyl, peduncle and vascular bundles in root tissues. Overexpression of the CdI19 cDNA conferred Cd tolerance in transgenic Arabidopsis. These results suggest that CdI19 plays an important role in the maintenance of heavy metal homeostasis and/or in detoxification by endowing plasma membranes with the capacity to serve as an initial barrier against inflow of free heavy metal ions into cells.

Background: Patent ductus venosus is extremely rare with only 14 cases reported in the world literature. We present a case of patent ductus venosus. Methods and Results: A 29-year-old male was admitted with melaena stool caused by gastric haemorrhagic ulcers. Laboratory data disclosed severe anaemia; however, liver function tests were normal. Serum ammonia was also within the normal range. Serological viral markers for hepatitis B or C were all negative. The abdominal ultrasonography and computed tomography indicated a 12 mm diameter shunt located in the left lobe of the liver, which connected the portal vein with the left hepatic vein. After treatment for gastric ulcers, percutaneous transhepatic portography was performed and an enormous shunt connecting the umbilical portion of the portal vein with the left hepatic vein was revealed. Conclusions: Histological findings of the liver biopsy showed that portal venules could not be observed in the portal areas and that no fibrosis or inflammatory cell infiltration were shown. Because of the anatomical position of the shunt, the case was diagnosed as patent ductus venosus.

The O-acetylated and O-methylcarbonylated analogue of the methanesulfonate (I) suffer from low product yield or no product formation at all.

A highly diastereo- and enantioselective Diels—Alder reaction of the new precursor α-amino-o-quinodimethane with α,β-unsaturated aldehydes is achieved in the presence of L-proline.

Powdery reagents obtained by complete alkaline hydrolysis of arylgermanium trichlorides were found to undergo the palladium-catalyzed cross-coupling reaction with aryl bromides and iodides in good yields. The reaction is performed in an aqueous medium taking sodium hydroxide as an activator. Some base-sensitive functionalities such as acetyl and trifluoromethyl groups survived the reaction.

Wounding induces expression of genes encoding defense-related proteins involved in wound healing. An intensive survey has been carried out to clarify the initial signal transduction pathways that mediate this stress to expression of genes. In this context, signal molecules that intermediate in the wound signal to cellular response have been actively searched for. Jasmonic acid (JA) has been considered to be a key signal molecule in this pathway. Systemin, ABA, ethylene, and electrical current have been suggested to function by transmitting the wound signal to JA. A mitogen-activated protein kinase has been shown to respond rapidly to wounding, and proposed to function as one of the key enzymes involved in JA biosynthesis. Transgenic plants overexpressing a gene encoding a Rab-type, small GTP-binding protein contained 6-fold higher levels of cytokinins than wild-type plants, and responded to wounding by rapidly producing JA and, uncommonly, accumulating salicylic acid (SA), a pathogenic signal. These phenomena observed in the transgenic plants were reproduced when wild-type plants were wounded in the presence of the synthetic cytokinin, benzylaminopurine, suggesting that cytokinins are indispensable in the control of endogenous levels of JA and SA.

Fibrolamellar hepatocellular carcinoma (FLHCC) is an entity distinct from ordinary hepatocellular carcinoma and is very rare in Oriental countries. We present here a Japanese case of FLHCC in a 25 year old woman, and review Japanese cases of FLHCC. The patient had mild abdominal pain when the hepatic tumour was revealed by ultrasonography. Hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody were negative and serum alpha-fetoprotein (AFP) was within the normal limit. Ultrasound-guided fine needle biopsy was performed and the tumour was histologically diagnosed as FLHCC. A right lobectomy of the liver was then performed. Macroscopically, the tumour (10 x 10 x 8 cm) was circumscribed, rather hard and yellowish white. Microscopically, neoplastic hepatocytes were polygonal and large with eosinophilic cytoplasm, which contained pale bodies. A number of fibrous stroma were arranged in thin parallel bands. Consequently, the case was diagnosed as FLHCC. In Japan, approximately 18,000 people die of ordinary hepatocellular carcinoma annually, while only nine cases (including the present case; six males, three females) of FLHCC in Japanese subjects have been reported previously. The mean age of the Japanese cases of FLHCC is 20.9 years old. One case with positive HBsAg, liver cirrhosis and high level of AFP was observed of nine cases. The nature of FLHCC in Japanese subjects may not be significantly different from that in Caucasians, except for male predominance.

O-acetylserine (thiol) lyase (EC4.2.99.8) is the key enzyme in the cysteine biosynthetic pathway of plants and prokaryotes. The gene, cys1, encoding this enzyme was isolated from a wheat (Triticum aestivum L.) cDNA library, and its deduced amino acid sequence found to show 53% sequence identity with the O-acetyl-serine (thiol) lyase of Escherichia coli and Salmonella typhimurium. The deduced peptide consists of 325 amino acids (34.1 kDa), contains a conserved motif for the binding of pyridoxal phosphate, a co-factor required for enzymatic activity, and an N-terminal region of 37 amino acid residues resembling chloroplast transit peptides. The identity of cys1 was further demonstrated through complementation of an E. coli cysteine auxotroph, which lacks O-acetylserine (thiol) lyase, by expression of the wheat gene. Northern blot analysis showed that cys1 is highly expressed in green vegetative and reproductive tissues and in the roots of wheat, as well as in the leaves of several plant species. Southern blot analysis demonstrated that the gene exists as a single copy in the wheat genome. Tobacco plants transformed with cys1 in the sense orientation (sense plants) or antisense orientation (antisense plants), under the control of the CaMV 35S promoter, showed high levels of transcripts. The O-acetylserine (thiol) lyase activity in transgenic plants was determined, and found to be three- to fivefold higher in sense plants than in control plants, but unaffected in antisense transformants. Fumigation experiments with toxic levels of hydrogen sulphide (H2S) gas showed that while sense transformants were highly resistant, control and antisense plants were severely damaged by the treatment.

The complete structure of paxisterol 1, produced by a Penicillium species, was determined by means of spectral and chemical studies of the parent compound and several of its derivatives. Paxisterol is a unique sterol, having an acetal structure at C-18. Application of 2D-INADEQUATE technique in 13C NMR spectral analysis was useful in this structure determination, where all carbon-carbon bonds in the molecule were demonstrated. Absolute stereochemistry was confirmed by the CD spectrum of 3-keto derivative 10 of compound 1 to be the same as that of cholesterol. An interesting acetal migration reaction was observed during the chemical conversions.

Seven novel potent antitumor antibiotics, duocarmycins A (1), C1 (2), C2 (3), D (4), B1 (5), B2 (6) and SA (7), were isolated from three independently collected Streptomyces sp. The complete structures, including absolute stereochemistry, were determined by spectral and chemical studies of those duocarmycins and several derivatives. Duocarmycins A (1) and SA (7) possess a 1,2,7,7a-tetrahydrocycloprop[1,2-c]indol-4-one subunit, a common pharmacophore with that of CC-1065 (10) found from Streptomyces zelensis.

o -Tributylstannylmethyl benzaldehyde reacts with Zn in the presence of TMSCl and 2,6 lutidine at room temperature to give α-trimethylsiloxy- o -quinodimethane, which is trapped with dienophiles to afford cycloadducts in good to high yields.

In the course of our screening for new anticancer compounds produced by marine bacteria, we found that a new genus marine bacterium Pelagiobacter variabilis produced new phenazine antibiotics, pelagiomicins A, B and C. Those compounds were labile in water and alcohols. The absolute structure of the main component, pelagiomicin A, and the structures of the minor ones were determined from the spectroscopic data and by synthesis. Pelagiomicin A exhibits activity against Gram-positive and -negative bacteria and antitumor activity in vitro and in vivo.

A novel glycosidic compound, suomilide ( 1 ), was isolated together with 1-( O - α -glucopyranosyl)-3,25-hexacosanediol, a “heterocyst glycolipid” from the non-toxic Nodularia spumigena HKVV. Their structures were determinated by 2D-NMR techniques and MS/MS experiments.

A new xanthine oxidase inhibitor named hydroxyakalone was isolated from the culture broth of a marine bacterium Agrobacterium aurantiacum N-81106. Structure of hydroxyakalone was determined to be 4-amino-1H-pyrazolo[3, 4-d]pyrimidine-3-one-6-ol by the spectral studies of hydroxyakalone and its permethyl derivative. The concentration to induce 50% inhibition (IC50) was 4.6μM against xanthine oxidase.

A novel antibiotic named korormicin was isolated from the marine bacterium, Pseudoalteromonas sp. F-420. This strain was isolated from the surface of a macro alga Halimeda sp. collected from Palau (the Republic of Belau). The planar structure of korormicin was determined by the result of 2D NMR studies and mass spectral data. Korormicin had specific inhibitory activity against marine Gram-negative bacteria, but was inactive against terrestrial microorganisms.

Irradiation of o-formylbenzyltrialkylstannanes in benzene gives α-trialkylstannoxy-o-quinodimethanes which are trapped with dienophiles at room temperature to afford cycloadducts with high stereoselectivities, while the corresponding silane and germane gave a different type of o-quinodimethane and moderate stereoselectivities in cycloadditions.

Seven new macrolactins (named G~M) and known macrolactins A and F were isolated from a culture broth of Bacillus sp. PP19-H3. The strain had been isolated from the macroalga, Schizymenia dubyi. Macrolactin A, which was 24-membered lactone, had previously been reported to show antibacterial, cytotoxic and antiviral activities. The new macrolactins include 22-membered ring or dicyclic lactone in addition to geometric isomers of known macrolactins A and F. The antibacterial activities of all the macrolactins examined in this study were relatively weak.

The rgp1 gene, originally Isolated from rice seedlings, encodes a small GTP-binding protein which is related to the product of the human proto-oncogene, ras-p21. To determine the physiological role of the rgp1 protein, rgp1-p25, the coding region of rgp1 was introduced into tobacco plants in both sense and antisense orientations. Transformants, which were found to contain the rgp1 gene at up to three loci, showed distinct phenotypic changes. The most notable was a reduction in apical dominance with increased tillering, together with dwarfism or abnormal flower development or both. These effects were similarly observed in both sense and antisense transformants. Northern hybridization analysis showed that rgp1 was expressed only in phenotypically abnormal transformants and not in the apparently normal phenotypes. Furthermore, the R1 progenies from most transformants co-segregated into a 3:1 ratio for both kanamycin resistance and tillering. The expression of tgp1, a presumed tobacco homologue of rgp1, was markedly reduced in transformants expressing the antisense rgp1, whereas it was apparently unaffected in transformants with sense rgp1. These observations suggest that the phenotypic changes in antisense transformants may be mediated by an effect on native tgp1 mRNA, whereas in sense transformants the changes may be induced by over-production of rgp1-p25. The possibility that the increased tillering may be related to abnormal phytohormone metabolism or response pathways, and that rgp1-p25 may mediate the transmission of signals in these pathways is discussed.

Details of the recently elucidated biosynthetic pathways of caffeine and related purine alkaloids are reviewed. The main caffeine biosynthetic pathway is a sequence consisting of xanthosine-->7-methylxanthosine-->7-methylxanthine-->theobromine-->caffeine. Genes encoding N-methyltransferases involved in three of these four reactions have been isolated and the molecular structure of N-methyltransferases investigated. Pathways for the catabolism of caffeine have also been studied, although there are currently no reports of enzymatic and genetic studies having been successfully carried out. Metabolism of purine alkaloids in species including Camellia, Coffea, Theobroma and Ilex plants is summarised, and evidence for the involvement of caffeine in chemical defense and allelopathy is discussed. Finally, information is presented on metabolic engineering that has produced coffee seedlings with reduced caffeine content, and transgenic caffeine-producing tobacco plants with enhanced disease resistance.

Hexaarylcyclotrisiloxane, which is one of the most stable derivatives of diarylsilanediol, was found to undergo palladium-catalyzed cross-coupling reaction with aryl halides in good yields. The reaction is performed in an aqueous medium taking potassium hydroxide as an activator. Both of the two aryl groups attached to each silicon atom could be utilized. Some base-sensitive functionality such as acetyl and nitro groups survived the reaction.

In order to improve light extraction from an organic light emitting diode (OLED), a novel structure of a top emission OLED was proposed by applying the diffraction layer. We have achieved 1.65 times higher light extraction efficiency in case of electroluminescence (EL), and 2.37 times in case of photoluminescence (PL).

Copper (I) and silver carbonyl catalysts were prepared in strong acids such as sulfuric acid, hydrogen fluoride, boron trifluoride-hydrate and fluoro sulfuric acid. Carbonylation of olefins, alcohols, dienes, diols, aldehydes and saturated hydrocarbons were carried out under atmospheric pressure and at room temperature by using copper (I) carbonyl catalyst, and tert-carboxylic acids were prepared in high yield.The highly hindered carboxylic acid was prepared from isobutylene oligomer. The industrial process of highly hindered carboxylic acid was established by using sulfuric acid-phosphoric acid-water mixed solvent in the recycle use of catalyst, and pilot plant started in 1988. This carbonylation method is available to the production of another compound also.The derivatives of highly hindered carboxylic acid is stable to hydrolysis and heat. The usages of this hindered carboxylic acid are paint, microgel, surfactant, stabilizer, initiator of polymerization, agricultural chemicals.

Palladium-catalyzed reactions of heteroaromatic tins with 2-ethoxyallyl diethyl phosphate and of nitrophenyltins with 2-methoxymethoxyallyl chloride were found to give the coupling products, which can be hydrolyzed to the corresponding acetonylated aromatics in good yields.

In order to clarify the characteristics of infectious mononucleosis hepatitis (IMH) in Japan, 20 cases with IMH treated at Kamo Hospital during the past 6 years (Group I) were analysed in comparison with cases of acute viral hepatitis, especially type A. The test for heterophil antibody was positive in only two cases. During the same period 209 cases were treated for acute viral hepatitis (type A: 77 cases = Group A; type B: 61 cases; type non-A, non-B: 71 cases). In Group I the common clinical symptoms and signs were headache, sore throat and lymph node swelling; jaundice was not as common as in Group A. GOT and GPT activities increased moderately in the acute stage, but they were significantly lower than those in Group A. LDH, AP, GGT and LAP activities were disproportionately higher to GPT activity in Group I. Liver biopsy in the convalescent stage showed that lipofuscin deposition and sinusoidal mononuclear cell infiltration were more prominent in Group I, while sinusoidal neutrocyte infiltration and focal necrosis at periportal areas were more common in Group A. Differential diagnosis of the two diseases could be made using these clinical features and histological findings. However, immunological differentiation is required for specific diagnosis because some features such as fever, prolonged elevation of thymol turbidity test, atypical lymphocytes in peripheral blod and predilection for young people were observed in both groups. Furthermore, the present study indicated that IMH is no longer rare and most cases do not demonstrate heterophil antibody in Japan.

Two types of thionin (Th)-polymers were prepared and their characteristics in the photogalvanic effects were studied by the use of thin-layer photocells. One type of the polymers being soluble in methanol was somewhat cross-linked by Th nuclei, and was cast on a water containing (Fe(II) solution) membrane between SnO2 and Pt electrodes. This membrane type thin-layer photocell generated larger photo-induced electricity than the similar thin-layer photocell composed of the corresponding monomeric Th/Fe(II) solution, the reason of which was considered to be due to the electrostatic effect of cationic sites incorporated into the polymers. Another type of polymers was used as water-containing (Fe(II) solution) gels, and the thin-layer photocells composed of them generated a very small photo-induced electricity due to the strong steric hindrance of entangled strands, which should decrease the possibility of the electrode reaction.

Variously composed copolymers from styrene and 4-vinylpyridine (4-VP) were prepared and their complex formation reactions with benzylbis(dimethylglyoximato)Co(III) [BzCo(III)(DMG)2] and N,N′-ethylenebis(salicylideneiminato)Co(II) (Co(II)salen) were studied kinetically by the stopped-flow rapid scanning spectroscopy. For the complex formation reaction with BzCo(III)(DMG)2, the relationship between the complex formation constant K and the content of 4-pyridylethylene units in the copolymers showed an unusual bell-type curve, and the K values were higher than the K value of complexation with pyridine. From the correlation between K, k (complex formation rate constant), and k′ (complex dissociation rate constant), it resulted that (1) the higher K values of the polymer systems are due to the lower k′ values compared with the pyridine system, and (2) the bell-type change of the K values is also caused by the k′ values. In the case of Co(II)salen-copolymer systems, two species of the complex, i.e., mono- and diaxial coordinated complexes were clearly identified by spectrometric kinetics, whereas the pyridine system gave only a mono-axial coordinated complex. The diaxial coordination seems to lead to a much more favorable structure than the monoaxial one, due to the entropic gain or to the polymer chelate effect.

Catalytic properties of terminal riboadenylate transferase from Escherichia coli and the products of the enzymic reaction were investigated. The kinetic analysis revealed that the reaction obeys the sequential ordered bi-bi mechanism. The application of conditions elaborated in this study resulted in the synthesis of products of defined size and efficient primer utilization. The tRNA(rA)n obtained was a good template for the synthesis of complementary DNA with reverse transcriptase.

DNA methyltransferase was purified 310-fold from a green alga, Chlamydomonas reinhardi vegetative cells. The native enzyme of molecular weight 55 000--58 000 catalyzed the transfer of methyl groups from S-adenosylmethionine to the 5 position of cytosine in DNA. Native DNA accepted methyl groups 10-fold more than did denatured DNA. The sequence specificity analysis of methylated deoxycytidine in vitro revealed that the enzyme introduces methyl groups preferentially into sequences containing 5'd(T-mC-R)3'. Kinetic analysis of the reaction indicated that the enzyme obeys a random sequential mechanism. The extent of saturation with methyl groups depends upon the species from which the DNA was obtained. Kinetic analysis of the reaction catalyzed by RNA polymerase II has indicated that DNA methylation decreases the rate of initiation of RNA synthesis, but does not affect the rate of RNA chain elongation.

The growth and IAA-oxidase activity of light-grown cucumber seedlings (cv. Aonagajibae) were investigated in response to GA3 and IAA. Both GA3 and IAA induced significant elongation of the hypocotyl. The fresh and dry weights of the hypocotyl increased due to GA3 or IAA treatment, whereas no significant change was observed in the cotyledons of GA3-treated seedlings as compared with the controls. The fresh and dry weights of IAA-treated cotyledons were both lower than those of controls. Treatment with GA3 or IAA resulted in retardation of IAA-oxidase activity in the hypocotyl and cotyledons. The degree of retardation was less in the cotyledons than in the hypocotyl. An inverse relationship was recognized between GA3- or IAA-induced elongation and IAA-oxidase activity in the hypocotyl. The auxin-mediated mechanism for gibberellin action was discussed.

A variety of gold catalysts can be used to catalyze the oxidation of carbon monoxide at temperatures as low as −70 °C and are stable in a moistened gas atmosphere. The novel catalysts, prepared by coprecipitation, are composed of ultra-fine gold particles and one of the oxides of 3d transition metals of group VIII, namely, Fe, Co, and Ni.

Treatment of carboxylic esters derived from alcohols with triphenylsilane in the presence of a radical generator at 140 °C gave the corresponding hydrocarbons in good yield.

Palladium catalyzed reaction of acyltins with organic halides were investigated. Among the halides, acyl halides and allylic halides were good substrates, and the latter gave allylic ketones in good yields.

2′-N-Acetyl-4′,6′-di-O-acetyl-3,3a-O-carbonyl-3′-deoxydihydrostreptobiosamine (15), a precursor in the synthesis of 3″-deoxydihydrostreptomycin, was prepared from benzyl α-dihydrostreptobiosaminide. The synthesis involves formation of L-allo compound (5) with inversion of the 3′-hydroxyl group of L-gluco derivative (2) in order to facilitate 3′-chlorination, dechlorination, of the 3′-chloro-L-gluco derivative (7 or 11) with tributyltin hydride, and utilization of cyclic 3,3a-O-carbonyl group instead of 3,3a-O-isopropylidene group which was unstable in the later reactions.

The reactions of benzyl 4,6-O-benzylidene-2-benzyloxycarbonylamino-2-deoxy-3-O-mesyl-α-D-glucopyranoside (1), its N-methyl derivative (4) and 3-epimer (8) with sodium iodide in DMF were studied. Compound 1 gave several products including 2,3-alloepimine, 4 an oxazolidinone and 8 a 3-iodo derivative.

Direct transformation of aryl bromides to benzylic alcohols by means of hydroxymethyltributyltin in the presence of palladium complex was attained in moderate yields, although the catalytic efficiencies were rather low, and the reaction could not be applied to aryl bromides having strong electron-withdrawing group. These problems were solved by using the trimethylsilyl-protected tin compound.

Acetates which were derived from primary, secondary, and tertiary alcohols were deoxygenated to the corresponding hydrocarbons in high yield by p-bis(diphenylhydrosilyl)benzene under homolytic conditions.

Palladium or ruthenium catalyzed cross-coupling of α-halo ketones with tributyltin enolates gave unsymmetrical 1,4-diketones, The method was applied to the dihydrojasmone synthesis.

On fait reagir ici le triphenylsilane dans des conditions radicalaires sur divers furanoses et pyranoses

Benzyl alcoholysis and hydrolysis of tetrakis-N-(benzyloxycarbonyl)fortimicin B and further transformation of the solvolysis products are described. Several derivatives of 6-epi-purpurosamine B and fortamine potentially useful for the synthesis of fortimicin analogs are presented.