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Selenium is an essential micronutrient that is beneficial to human health. Selenium-containing drugs have been developed as antioxidants, anti-inflammatory, and anticancer agents. However, the synthesis of selenium-containing chalcones has not been fully explored. Therefore, we report the synthesis of novel selenophene-based chalcone analogs and reveal their biological activities as anticancer agents. Among the seven synthesized molecules, compounds 6, 8, and 10 exhibited anticancer activity with IC

Naphthalimide derivatives have multiple biological activities, including antitumour and anti‐inflammatory activities. We previously synthesized several naphthalimide derivatives; of them, compound 5 was found to exert the strongest inhibitory effect on human DNA topoisomerase II activity. However, the effects of naphthalimide derivatives on platelet activation have not yet been investigated. Therefore, the mechanism underlying the antiplatelet activity of compound 5 was determined in this study. The data revealed that compound 5 (5–10 μM) inhibited collagen‐ and convulxin‐ but not thrombin‐ or U46619‐mediated platelet aggregation, suggesting that compound 5 is more sensitive to the inhibition of glycoprotein VI (GPVI) signalling. Indeed, compound 5 could inhibit the phosphorylation of signalling molecules downstream of GPVI, followed by the inhibition of calcium mobilization, granule release and GPIIb/IIIa activation. Moreover, compound 5 prevented pulmonary embolism and prolonged the occlusion time, but tended to prolong the bleeding time, indicating that it can prevent thrombus formation but may increase bleeding risk. This study is the first to demonstrate that the naphthalimide derivative compound 5 exerts antiplatelet and antithrombotic effects. Future studies should modify compound 5 to synthesize more potent and efficient antiplatelet agents while minimizing bleeding risk, which may offer a therapeutic potential for cardiovascular diseases.

In our previous study, we have demonstrated that curcumin can efficiently kill the anaerobic bacterium Propionibacterium acnes by irradiation with low-dose blue light. The curcuminoids present in natural plant turmeric mainly include curcumin, demethoxycurcumin, and bisdemethoxycurcumin. However, only curcumin is commercially available. Eighteen different curcumin analogs, including demethoxycurcumin and bisdemethoxycurcumin, were synthesized in this study. Their antibacterial activity against Gram-positive aerobic bacteria Staphylococcus aureus and Staphylococcus epidermidis was investigated using the photodynamic inactivation method. Among the three compounds in turmeric, curcumin activity is the weakest, and bisdemethoxycurcumin possesses the strongest activity. However, two synthetic compounds, (1E,6E)-1,7-bis(4-bromophenyl)hepta-1,6-diene-3,5-dione and (1E,6E)-1,7-bis(3-bromophenyl)hepta -1,6-diene-3,5-dione, possess the best antibacterial activity among all compounds examined in this study. Their chemical stability is also better than that of bisdemethoxycurcumin, and thus has potential for future clinical applications.

We synthesized multiple cinnamils and quinoxalines to evaluate their anticancer activity. Cinnamils were used as precursors for quinoxalines via condensation with 1,2-diaminobenzene. Among the 26 synthesized compounds reported in this article, we found that cinnamil 3l exhibited its inhibitory effect with an IC

The reaction of 5-amino-2-[2-(dimethylamino)ethyl]-6-phenyl-1H-benzo[de]isoquinoline-1,3(2H)-dione with a series of aldehydes in acidic media (phosphoric acid, trifluoromethanesulfonic acid, and trifluoroacetic acid) is described. This key step is based on the Pictet–Spengler reaction to synthesize ten novel isoquinolino[5,4-ab]phenanthridine derivatives. The most effective acid is phosphoric acid and optimized yields were obtained. The frameworks of target compounds are unique and have never been reported.

Borneol is a plant terpene commonly used in traditional Chinese medicine. Optically pure (+)-borneol and (-)-borneol can be obtained by extraction from the plants Dipterocarpaceae and Blumea balsamifera, respectively. "Synthetic borneol" is obtained from the reduction of (±)-camphor to lead to four different stereoisomers: (+)-isoborneol, (-)-isoborneol, (+)-borneol, and (-)-borneol. In contrast, "semi-synthetic borneol" is produced from the reduction of natural camphor, (+)-camphor, to afford two isomers: (-)-isoborneol and (+)-borneol. We established a convenient method to identify them by treating the four stereoisomers with two chiral reagents, (R)-(+)-α-methoxy-α-trifluoromethylphenylacetyl chloride ((R)-(+)-MTPA-Cl) and (1S)-(-)- camphanic chloride. The resulting derivatives from the above mentioned method were analyzed by gas chromatography. The enantiomers of (+)- and (-)-isoborneol were successfully separated from (+)- and (-)-borneol isomers in this study to make this a useful method in the identification of "synthetic" and "semi-synthetic" borneols. Furthermore, we also examined five different commercial borneols. During this course, a novel and unprecedented partial epimerization from isoborneol-camphanic ester to borneol-camphanic ester was observed. However, this phenomenon did not occur in isoborneol-MTPA esters epimerization to borneol-MTPA case under the same conditions. The DFT calculation of activation energies for both reactions was in a good agreement with the results obtained from GC analysis.

A systematic study of the synthesis of halo-substituted azachalcones was conducted. During the reaction course, we obtained not only the target azachalcones, but also penta-substituted cyclohexanols, which are seldom reported in the literatures. The formation of penta-substituted cyclohexanols was dependent on equivalents of base used and reaction time. Their formation followed a tandem reaction: Claisen-Schmidt condensation, three Michael reactions, retro-aldol reaction, and intramolecular aldol cyclization.

A facile synthesis of six new deoxyfluoro querciotls from d -(−)-quinic acid is described. The key steps involve the regioselective fluorination as well as highly stereoselective dihydroxylation. These synthetic deoxyfluoro quercitols are considered as potential glycosidase inhibitors.

DFT/B3LYP/6-311++G(d,p) calculations have been performed to obtain optimized structures for fourteen conformers of (3 R ,4 R ,5 R ,7 S )-7-(hydroxymethyl)thiepane-3,4,5-triol. These conformers are considered as the twist-chair (TC) and twist-boat (TB) conformations. Among all conformers, the TCS5 and TCS6 conformers appear to be the most energetically stable since they contain an intramolecular hydrogen bond between hydroxyl group at C(8) and S atom. Boltzmann weighting factor analysis provides valuable information on the population of the fourteen conformers, including both the TC and TB conformations. The analysis results demonstrate that the TCS2, TCS5, and TCS6 conformers provide a major population contribution with Boltzamann weighting factors larger than 7% as compared to other conformers. For these conformers of (3 R ,4 R ,5 R ,7 S )-7-(hydroxymethyl)thiepane-3,4,5-triol, the GIAO/HF, GIAO/DFT/OPBE, GIAO/DFT/B3LYP and GIAO/DFT/mPW1PW91 calculations with the 6-311++G(d,p), 6-311+G(2d,p), cc-pVDZ and cc-pVTZ basis sets were used to obtain their 13 C NMR chemical shifts. The calculated 13 C NMR chemical shifts of the TCS2, TCS5, and TCS6 conformers show a close correlation with experimental data, within 2.4–3.0 ppm of MAE values. The experimental 13 C NMR chemical shifts represent a combination of contributions from all the conformers. In our investigation, the calculated 13 C NMR chemical shifts of the mixture of (3 R ,4 R ,5 R ,7 S )-7-(hydroxymethyl)thiepane-3,4,5-triol conformers display a remarkable MAE and RMS improvement comparing to those for each individual conformer. The most appropriate calculation method and basis set to evaluate the theoretical 13 C NMR chemical shifts for these conformers are OPBE/6-311+G(2d,p). Calculated results represent that the conformation of (3 R ,4 R ,5 R ,7 S )-7-(hydroxymethyl)thiepane-3,4,5-triol can be determined by the intramolecular hydrogen bond which could be simulated by the 13 C NMR chemical shift calculation.

Aminoflavonoids are unique antioxidants comparing to other abundant flavonoids in nature. Their syntheses and biological activities were scarcely reported. An effectively copper-mediated amination of the corresponding bromoflavonoids to synthesize a series of new aminoflavonoids is described.

Seven thiepanes, the seven-membered-ring thiosugars, were first synthesized in 11–12 steps starting from d -(−)-quinic acid. Each thiepane is unique for its flexible conformation with a hydroxymethyl group at its C7 position. The key step was the deprotection of ether groups in compounds 7 , 8 , and 18 – 21 by 1.0 M BCl 3 of CH 2 Cl 2 solution at −78 °C to lead to the corresponding thiepanes. These target molecules all exhibited the twisted chair conformation that fully agreed with our previous report.

Borneol is a monoterpene that is widely used in traditional Chinese medicine. There are two different products sold in Taipei's traditional Chinese medicine market, natural and chemically synthesized borneol. Chemically synthesized borneol contains four stereoisomers, (+)-isoborneol, (−)-isoborneol, (−)-borneol, and (+)-borneol. The ratio of these four isomers in chemically synthesized and natural borneol products was determined by gas chromatography mass spectrometry. A huge variation between these products is highlighted in this survey. The results suggest that the Food and Drug Administrations in Asian countries should establish a regulatory standard regarding the ratio of the four different borneol isomers in both natural and chemically synthesized borneol.

Novel C4-benzazole naphthalimide derivatives were synthesized and tested in vitro and in vivo as anti-cancer drugs. Among these synthetic molecules, compounds 9 and 10 exhibited cytotoxicity against murine B16F10 melanoma cells. In addition, the above-mentioned compounds significantly suppressed lung tumor metastasis with no visible sign of toxicity.

The antioxidant ability of an array of commercially available flavonoids was evaluated on the larvae of the zebrafish model organism, in order to find flavonoids with lower toxicities and higher radical oxygen-scavenging properties than flavone. Among the flavonoids tested, chrysin and morin possessed higher reactive oxygen species (ROS)-scavenging rates (−99% and −101%, respectively) and lower toxicity (LD 50 > 100 ppm). Zebrafish fins in the UVB + chrysin group were 6.30 times more likely to grow to normal fin size than those in the UVB-only control group, while zebrafish fins in the UVB + morin group were 11.9 times more likely to grow to normal fin size than those in the UVB-only control group. These results were analysed by the QSAR method and were in accordance with predicted values. A new 4′-fluoroflavone was synthesised. The ROS-scavenging rate of 4′-fluoroflavone was −54%, which corresponds well with the predicted value (−48%). We propose that a combination of QSAR prediction and the zebrafish model organism is efficient for evaluating new flavonoids.

DFT/B3LYP/6-311++G(d,p) calculation of the relative stable conformations of (3R,4R,6S)-trihydroxyazepane are presented. The GIAO/DFT/OPBE, GIAO/DFT/B3LYP and GIAO/HF single point calculations with 6-311++G(d,p), 6-311+G(2d,p), cc-pVDZ and cc-pVTZ basis sets of (3R,4R,6S)-trihydroxyazepane were conducted to generate their 13C NMR chemical shifts. According to calculation results, 14 (3R,4R,6S)-trihydroxyazepane with optimized structure were generated. There were three conformers which contain the intramolecular hydrogen bonding exhibit a lowest electronic energies and TCN1(eq) was the most stable conformer than others. Boltzmann weighting factor analysis exhibits that TCN1(eq), TCN3(eq) and TCN5(eq) dominate a major contribution among the 14 conformers. The individual calculated NMR results of TCN1(eq), TCN3(eq) and TCN5(eq) represents a quite close correlation with experimental data. Moreover, the experimental 13C NMR chemical shifts gave only the average contribution of all conformers. In our investigation, the calculated 13C NMR chemical shifts of mixture (3R,4R,6S)-trihydroxyazepane exhibit a good agreement with the experimental NMR data. Calculated NMR results of mixture (3R,4R,6S)-trihydroxyazepane conformers display a remarkable MAE and RMS improvement over that of each individual conformer. A good calculation method and basis set choice to evaluate the theoretical chemical shifts for these conformers is HF/cc-pVTZ.

One-pot synthesis of a new 2-pyrone dye ( 3a ) by the reaction of 4-diethylamino-acetophenone ( 1 ) with methyl 2-cyano-3,3-bis(methylsulfanyl)acrylate ( 2 ) in the presence of sodium hydroxide as the base was carried out in DMSO. Compound 4a was synthesized by the replacement of methylsulfanyl group of 3a with dimethylamine at 4-position of pyrone ring. Similarly, compound 5a was prepared via the reaction of 3a with diethyl malonate. Compounds 3a–5a exhibited the following fluorescence in the solid state: red ( 3a ), green ( 4a ), and orange ( 5a ). In addition, it was revealed that 2-pyrone dyes exhibit fluorescence in various solvents and show positive solvatochromism. Compounds 3a and 5a exhibited intense fluorescence in chloroform and dichloromethane (fluorescence quantum yield Φ : 0.94–0.95). In contrast, compound 4a exhibited intense fluorescence in polar solvents (methanol: Φ = 0.92). These 2-pyrone dyes have the potential for applications in various fields.

A Paenibacillus sp. strain 2S-6 was isolated from the black liquor of the first brownstock washing stage of kraft pulping process and identified by its 16S rDNA sequence. This bacterial strain utilized a variety of saccharides and polysaccharides as carbon source, but neither lignin nor lipids. Crude xylanase from Paenibacillus sp. 2S-6 was produced in a 5 L laboratory fermenter at 37 °C, pH 7. After 24 h, up to 10.5 IU xylanase per mg of protein in the crude extract of fermentation broth was obtained. After two-stage ultrafiltration, the optimal activity of partially purified xylanase reached 60.51 IU/mg at 50 °C, pH 6. A major band indicating molecular weight of 33 kDa was shown on SDS-PAGE for the partially purified xylanase. After 4 h at 60 °C, 48.99% and 31.25% residual xylanase activities were demonstrated at pH 7 and 9, respectively. Efficacy of its xylanase on the bleaching agent saving was demonstrated by using 5 IU xylanase per gram oven-dried pulp prior to bleaching, referred as biobleaching. Identical levels of brightness and higher levels of viscosity were obtained for the xylanase pretreated eucalypt kraft pulps followed by a 20% reduction of the bleaching agent dosage in the first step of a commercial C70/D30-Eo-D bleaching sequence.

Wetland biomass has potentials for bioenergy production and carbon sequestration. Planted with multiple species macrophytes to promote biodiversity, the 3.29 ha constructed wetland has been treated 4000 cubic meter per day (CMD) domestic wastewater and urban runoff. This study investigated the seasonal variations of aboveground biomass of the constructed wetland, from March 2007 to March 2008. The overall aboveground biomass was 16,737 kg and total carbon content 6185 kg at the peak of aboveground accumulation for the system emergent macrophyte at September 2007. Typhoon Korsa flood this constructed wetland at October 2007, however, significant recovery for emergent macrophyte was observed without human intervention. Endemic Ludwigia sp. recovered much faster, compared to previously dominated typha. Self-recovery ability of the macrophyte community after typhoon validated the feasibility of biomass harvesting. Incinerating of 80% biomass harvested of experimental area in a nearby incineration plant could produce 11,846 kWh for one month.

spectroscopy. Organically extracted crude soapnut saponin was employed as the standard. Linearity for the calibration graphs was found for the range of organic extracts of crude saponin down to 0.2 g/L aqueous solutions, for all three assays studied. The area of the main peak in the HPLC chromatograms and the absorbance values of two colorimetric assays of the commercial glycerin clear soap base with predetermined amount of soapnut extract were recorded and compared with calibration graphs constructed with an aque- ous saponin solution. It was found that HPLC analysis provided more precise values then the two colori- metric assays. Discrepancies were found between the saponin contents for 12 commercial cleaning prod- ucts in Taiwan as analyzed by HPLC and the values estimated by antimony pentachloride and vanillin-sulfu- ric colorimetric assays.

In continuation of our interest in the synthesis of glycosidase inhibitors, we report herein an efficient synthesis of three new polyhydroxylated amino cyclohexane derivatives (aminocyclitols) that may potentially possess important biological activities. The key step involved the highly stereoselective dihydroxylation of protected azido cyclohexene derivatives 5, 9, and 15, which were easily red from D-(-)-quinic acid. The subsequent hydrogenation step was conducted under acidic conditions to provide the target molecules in an efficient manner with high overall yields.

We report herein that the new seven‐membered‐ring thiosugars (thiepanes) have been synthesized from d‐(‐)‐quinic acid. The key feature of the synthesis involves the thiocyclization of protected hexane‐1,2,3,5,6‐pentanol derivatives. The subsequent step of acidic removal of protecting groups is critical in the reaction conditions to obtain the required 3,4,6‐trihydroxythiepanes. During the course of studies, the unexpected trihydroxythiopyrans are formed because of the ring contractions of their corresponding trihydroxythiepanes under various conditions.

A new strategy for preparing room-temperature discotic nematic materials is proposed and developed stepwise to improve various discotic nematic properties. This approach replaces one sidearm of the discotic hexakis(4-hexyloxyphenylethynyl)benzene with a tris(alkoxy) sidearm, 1-ethynyl-2,3,4-tris(hexyloxybenzene), to lower transition temperatures, manipulate discotic nematic ranges, and preserve the discotic nematic superstructure while preventing column formation. Although symmetry considerations play a role in the resulting mesogenic properties, steric hindrance and van der Waals interactions are ascribed to the superior discotic nematic properties of the newly prepared discogens containing a laterally substituted sidearm.

Several new stereoisomers of 3,4,6-trihydroxyazepanes and 7-hydroxymethyl-3,4,5-trihydroxyazepanes as well as known 3,4,5-trihydroxyazepanes were synthesized as potent glycosidase inhibitors from D-(-)-quinic acid in an efficient manner. The key step employs dihydroxylation of protected chiral 1,4,5-cyclohex-2-enetriols under RuCl3/NaIO4/phosphate buffer (pH 7) condition, followed by reductive amino cyclization. We found the choice of an appropriate protecting group to C1-OH of chiral 1,4,5-cyclohex-2-enetriols would increase the yields of cyclization. The preliminary biological data indicate some of these azepanes possess potent inhibition against alpha-mannosidase and alpha-fucosidase.

Highly stereoselective epoxidations have been achieved in both cyclohexylidene acetal and butane 2,3‐bisacetal (BBA) protection of (1,4,5)‐cyclohex‐2‐ene‐triols. These epoxy derivatives are all derived from D‐(−)‐quinic acid and can be used for the synthesis of muco‐, (+)‐epi‐, (+)‐vibo, (−)‐talo, and (−)‐gala‐quercitols.

The highly stereoselective synthesis of (−)-epi-, (−)-allo- and neo-quercitols as well as stereospecific synthesis of (−)-talo- and (+)-gala-quercitols have been achieved. The general strategy is employing dihydroxylation of the isolated double bond of various kinds of protected chiral (1,4,5)-cyclohex-2-ene-triols, which are derived from d -(−)-quinic acid. The choosing of protecting groups from either BBA (butane 2,3-bisacetal) or acetyl groups will result in the various degrees of stereoselectivity of dihydroxylation. On the other hand, the cyclohexylidene acetal moiety is attributed to the stereospecificity during dihydroxylation to afford the request molecules.

We described herein the new synthesis of a trihydroxy piperidine derivative (1,4,5-trideoxy-1,5-imino- d -ribo-hexitol) and (+)-proto-quercitol from d -(−)-quinic acid, both are considered as inhibitors for glycosidases.

The synthesis of aminoflavonoids from the corresponding bromoflavones and bromoflavanols, respectively is studied.

The (Z)-(iodovinyl)oxetane 12 was prepared from D-glucose and the acyclic analog 18 was obtained from D-mannitol. Following the generation of their lithium derivatives by halogen−metal exchange, coupling to the enantiopure vinyl-substituted norbornanones 20, 23, and 29 proceeded exclusively via endo attack to deliver the targeted exo-carbinols. The anionic oxy-Cope rearrangements of 21 and 24 were seen to differ appreciably in rate. While the sulfur derivative 24 experiences [3,3] sigmatropy with a half-life of less than a minute at −78 °C, its oxygen analogue 21 proved unreactive below −20 °C under entirely comparable conditions. This phenomenon is critically examined in a synthetic context involving 26 and 30, where the heavily functionalized acyclic side chain involved previously is supplanted by an oxetane assembly. In the sulfur example, isomerization occurs very rapidly as before with 100% transfer of chirality. The kinetic response of vinyl ether 26 now proved to be entirely comparable. However, the pathway followed in this instance was intramolecular nucleophilic attack by the “naked” alkoxide at the less substituted C−O bond of the oxetane with ring cleavage and formation of alcohol 28. The global findings provide a glimpse of the subtle way in which [3,3]-sigmatropic transpositions can be modulated by heteroatomic substitution.

Using D-(-)-quinic acid as chiral building block, a series of novel seven-membered-ring thiosugars are synthesized.

Tuckolide (decarestrictine D), a 10-membered lactone isolated from P. corylophilum and polyporus tuberaster fungi that potently inhibits cholesterol biosynthesis, was synthesized. The key steps include a Sharpless catalytic asymmetric dihydroxylation reaction (AD) of the methoxymethyl (MOM) ether protected diene 2 and a direct Corey-Nicolaou lactonization reaction of seco-acid 1with added silver perchlorate. The selectivity of the dihydroxylation step was found to be highly dependent on the nature of the protecting group adjacent to the diene in 2. The selectivity of the asymmetric dihydroxylation reaction of 2 indicates that both steric and electronic effects can lead to significant amounts of the undesired isomers. This synthesis establishes the absolute stereochemistry of tuckolide showing the C3 hydroxyl bearing carbon with an S-configuration comparable in an absolute sense to that in the lactone portion of the HMG-CoA reductase inhibitor compactin.

We reported herein an efficient synthesis of l -allono-1,4-lactone from 2,3:5,6-di- O -isopropylidene- d -mannono-1,4-lactone in five steps. The key feature of this method involved a one-pot, ‘double inversion’ procedure at the stereocenters of C-4 and C-5 of d -mannono-1,4-lactone to afford the target molecule.

Xylooligosaccharides (XO), derived from the alkaline (NaOH) extractant of Mikania micrantha, were produced using multiple staged membrane separation and enzymatic xylanolysis. Staged nanofiltration (NMX), ultrafiltration (EUMX), and centrifugation (EMX) processes for the ethanol precipitates were conducted. NMX recovered 97.26% of total xylose and removed 73.18% of sodium ions. Concentrations of total xylose were raised from 10.98 to 51.85 mg/mL by the NMX process. Recovered xylan-containing solids were hydrolyzed by the recombinant Paenibacillus xylanase. 68% XO conversions from total xylose of NMX was achieved in 24 hours. Xylopentaose (DP 5) was the major product from NMX and EMX hydrolysis. Xylohexaose (DP 6) was the major product from EUMX hydrolysis. Results of the present study suggest the applicability for XO production by nanofiltration, as NMX gave higher XO yields compared to those from a conventional ethanol-related lignocellulosic waste conversion process.

We described herein a concise synthesis of 3′,4′-diaminoflavone 10. This new, three-step synthetic approach is more efficient than the conventional seven-step synthetic method. The route is shortened significantly by introducing the amino moieties early and eliminating the need for nitro group reduction. The other two analogues, 5,7-dihydroxy-3′,4′-diaminoflavone 11 and 5,7-dimethoxy-3′,4′-diaminoflavone 12, were also synthesized similarly. The above three compounds, along with flavone, were evaluated for their antioxidant and UVB-protection abilities on zebrafish larvae. The data showed that compound 10 exhibited the best result, with −102.3% of ROS-scavenging rate.

The theoretically predicted optimum length/breadth/width ratio for maximizing shape biaxiality was investigated experimentally by the facile and successful synthesis of cross-shaped compound 3, which showed enantiomeric nematic phase behavior. This cross-like core structure could alternatively be viewed as two fused V-shaped mesogens, which have recently immerged as a new direction in biaxial nematic research, at the bending tips that can act as a new structure for biaxial investigations. Whilst the thermal analysis data of compound 3 did not meet the expected theoretical values for biaxial nematics, surface-induced biaxiality was evidenced by optical studies. Cluster-size analysis within the nematic phase of compound 3 revealed the formation of meta-cybotactic nematics, which approached the cluster sizes of cybotactic nematics. The split small-angle 2D X-ray diffraction patterns of magnetic-field-aligned samples indicated that the nematic phase was composed of small smectic C-like clusters with the tilting of molecules within the clusters. The wide-temperature-range enantiomeric nematic phase of cross-like compound 3 enabled the molecular skeleton to serve as an alternative skeleton to bent-rod mesogens, which exhibited nematic phases with the potential competition of transitions to higher-order liquid-crystalline phases and crystallization, for future biaxial investigations.

An effective synthetic method for polyhydroxylated azepanes that contain an alkyl group (Me or Bu) at either the 7- or N-positions is developed. The synthetic routes are accomplished in eight to ten steps from d -(−)-quinic acid. Among the compounds synthesized, the polyhydroxy 7-butyl azepane (compound 3 ), which possessed the R -configuration at C-7 position, is shown to give potent inhibition against β-galactosidase (IC 50 = 3 μM). Preliminary biological data indicate that the length of alkyl groups along with the proper stereochemistry at the C-7 position is essential for acquiring extra binding affinity. Using similar synthetic routes, the polyhydroxy N -methyl and N -butyl azepanes are synthesized for the comparison of their biological activities.

Tetramethylguanidinium azide was used in the quantitative conversion of glycosyl halides 1 – 5 to the corresponding glycosyl azides 10 – 14. The stereoselective reactions occurred with complete inversion at the anomeric centers. The titled reagent was also employed in the selective synthesis of pseudoglycosyl azide 16 and two steroidal azides 17 and 18. All reactions were carried out in non-halogenated solvents to avoid potential explosion hazards.

A number of 3-substituted 1D-myo-inositols were synthesized and evaluated as substrates for phosphatidylinositol synthase and uptake by intact cells. 1D-3-Amino-, -3-chloro-, and -3-(acetylthio)-3-deoxy-myo-inositols were all synthesized by nucleophilic displacement of the 6-O-(trifluoromethyl)sulfonyl group of 1L-1,2:3,4-di-O-cyclohexylidene-5-O-methyl-6-O-[(trifluoromethyl)-sulfon yl] - chiro-inositol (which was prepared from L-quebrachitol), respectively, by reaction with LiN3, followed by reduction of the azido function, and with LiCl and KSAc to give the O-protected compounds. O-Demethylation using BBr3 and concomitant acetal hydrolysis furnished the free-hydroxy 3-amino- and 3-chloro-3-deoxy-1D-myo-inositols. The 3-mercapto analogue was obtained by removal of the acetal groups of the acetylthio analogue, followed by acetylation and purification of the peracetate, and subsequent O-demethylation and deacetylation. The 3-deoxy derivative was synthesized from the 6-O-(imidazol-1-ylthiocarbonyl) compound via Barton-McCombie deoxygenation. The 3-azido derivative was directly synthesized from 1L-1-O-tosyl-chiro-inositol via displacement with azide. The 3-keto analogue was prepared by Pt-catalyzed air oxidation of 1L-chiro-inositol. The compounds were all evaluated as substrates for phosphatidylinositol (PtdIns) synthase from mouse brain. The 3-NH2, 3-F, 3-deoxy, and 3-keto analogues all showed activity as substrates, as measured by liberation of cytidine monophosphate. These compounds also showed inhibition of the reaction of myo-[3H]inositol with PtdIns synthase. These results taken together indicate that these compounds are likely to be incorporated into phospholipids. As a further indication that these compounds might be useful as probes for the PtdIns pathway, it was demonstrated that the 3-NH2, 3-F, and 3-deoxy compounds are taken up by intact fibroblast cells as evidenced by their competing with myo-[3H]inositol uptake.