Novel concept of enzyme selective nicotinamide adenine dinucleotide (NAD)-modified inhibitors based on enzyme taxonomy from the diphosphate conformation of NAD.

The dihedral angle θ of the diphosphate part of NAD(P) were investigated to distinguish the differences in the binding-conformation of NAD(P) to enzymes and to create an enzyme taxonomy. Furthermore, new inhibitors with fixed dihedral angles showed that enzymes could recognize the differences in the dihedral angle θ. We suggest the taxonomy and the dihedral angle θ are important values for chemists to consider when designing inhibitors and drugs that target enzymes.

Synthesis of γ- and δ-lactone natural products by employing a trans-cis isomerization/lactonization strategy.

Alkaline hydrolysis of 4-hydroxy- or/and 5-hydroxy-(2E)-alkenoate followed by acid treatment gave the corresponding (2E)-alkenoic acids which were subjected to lactone formation reaction without further purification. The crude acids were treated with 2,4,6-trichlorobenzoyl chloride in pyridine to afford γ-lactone or δ-lactone, respectively, accompanied by trans-cis isomerization. By this procedure, (±)-(4,5)-trans-5-benzyloxy-2-hexen-4-olide (90% overall yield), (S)-5-hydroxy-2-penten-4-olide (86% overall yield), (4S,5R)-5-hydroxy-2-hexen-4-olide (86% overall yield), (4R,5S)-5-hydroxy-2-hexen-4-olide (82% overall yield), (S)-parasorbic acid (58% overall yield) and natural product, (5R,7S)-7-hydroxy-2-octen-5-olide (euscapholide: 20% overall yield) were synthesized.

The asymmetric syntheses of methyl D-digitoxoside, L-oleandrose and L-cymarose from methyl sorbate, an achiral precursor.

The addition of 4 eq of chloral to osmundalactone (4S,5R)-4 gave quantitative formation of the hemiacetal derivative (4S,5R)-8, which was treated with methane sulfonic acid to afford the intramolecular Micheal addition product (+)-(3S,4S,5R)-9 possessing a 3,4-cis-dihydroxy-δ-lactone in 78% overall yield from (4S,5R)-4. The obtained (+)-(3S,4S,5R)-9 was subsequently converted to methyl D-digitoxoside (pyranoside) (12) in 13% overall yield and methyl D-digitoxoside (furanoside) (12) in 20% overall yield. The reaction of benzyl-osmundalactone (4R,5S)-3 and MeOH in the presence of Amberlyst A-26 as a basic catalyst gave 3,4-trans-δ-lactone (-)-(3S,4R,5S)-20 in 28% yield and 3,4-cis-δ-lactone (-)-(3R,4R,5S)-21 in 45% yield. Dibal-H reduction of (-)-(3S,4R,5S)-20 followed by catalytic hydrogenation gave L-oleandrose (6) in 86% overall yield, while Dibal-H reduction of (-)-(3R,4R,5S)-21 followed by catalytic hydrogenation provided L-cymarose (7) in 85% overall yield.

Acid-promoted rearrangement of drimane type epoxy compounds and their application in natural product synthesis.

The reactions of (±)-α-epoxy drimenol (4) and (±)-α-epoxy drimenyl cyanide (6) with acids (proton acid or Lewis acid) selectively gave the rearranged aldehyde (±)-13 and (±)-15 having the hydroindane skeleton, respectively, while the reactions of (±)-4 and (±)-6 with Dibal-H selectively afforded the allyl alcohol (±)-14 and (±)-16, respectively. The reactions of (8aR)-6 and (8aS)-6 with Dibal-H were applied for the determination of the absolute structure of natural 7ß-acetoxy-ent-labda-8(17),13(14)E-dien-15-ol (18). The reaction of (±)-α-epoxy bicyclofarnesol (5) and (8aS)-5 with proton acid selectively provided the rearranged ketol (±)- and (8aS)-31 having the hydroindane skeleton, respectively. The optically active (8aS)-31 was converted to the natural (9S)-austrodoric acid (33).

Synthesis of (R)-curcumene and (R)-xanthorrizol based on 1,2-Aryl migration via phenonium ion.

Solvolysis reaction of methyl (4S,5S)-4-(4'-methoxyphenyl)-5-tosyloxy-2(E)-hexenoate 5 in water-saturated MeNO(2) gave the 1,2-migration product, (4S,5S)-5-hydroxy-4-(4'-methoxyphenyl)-2-(E)-hexenoate 6 (55% yield), which was converted to methyl (R)-(4'-methylphenyl)hexanoate 11 in 25% overall yield (5 steps). Treatment of (R)-11 with MeLi gave tertiary alcohol congener 12, which was subjected to dehydration to afford (R)-(-)-curcumene 1. An introduction of hydroxyl group at meta-position of the aromatic ring in (R)-11 was achieved based on consecutive treatment [1) selective iodination, 2) conversion of aryl iodide to aryl boronate, 3) conversion of aryl boronate to phenol]. Thus obtained phenol (R)-16 was treated with MeLi to give tertiary alcohol congener 17, which was subjected to dehydration to afford (R)-(-)-xanthorrizol 2.

Incoherent quasielastic neutron scattering study on the polymorphism of tristearin: dynamical properties of hydrocarbon chains.

Dynamical properties of acyl chains in the three polymorphic phases alpha, beta', and beta of tristearin [C(3)H(5)(OCOC(17)H(35))3] have been studied by means of incoherent quasielastic neutron scattering (IQNS) using selectively deuterated samples. The mean square displacement of hydrogen atoms, , was estimated from the scattering vector Q dependence of the elastic scattering component under the harmonic approximation. It was shown that the temperature dependence of was significantly different between the three phases. There was no marked difference in between these phases up to 193 K, and the value increased linearly with temperature. Although the beta phase remained linear up to 293 K, the alpha and beta' phases started to show a nonlinear increase around 200 K, suggesting an anharmonic nature of molecular motions. The alpha phase exhibited the most conspicuous temperature dependence. These characteristics were ascribable to the difference in the lateral packing of acyl chains. Compared with the beta phase which has a tightly packed T// subcell, the beta' and alpha phases have looser O perpendicular and H subcells, respectively. The molecular motion in the alpha phase was analyzed using the model of uniaxial rotational diffusion in a onefold cosine potential. It has been clarified that the rotational fluctuation about the chain axis in the alpha phase is rather restricted compared with that in the rotator phase of n-alkanes.

Solvolysis of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoate derivatives.

The solvolysis reaction of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoates 4a-k gave (4,5)-anti-4-aryl-5-hydroxy-2(E)-hexenoates 2a-k and (4,5)-anti-5-aryl-4-hydroxy-2(E)-hexenoates 5a-k along with the complete inversion. This 1,2-aryl migration was induced by treatment with heating in water-saturated nitromethane. On the basis of the substituent effect on the aromatic ring, this 1,2-aryl migration is thought to proceed via the sigma-bridged phenonium ion. The product selectivity between 2a-k and 5a-k was found to be subtly governed by the substituent and substitution pattern in the aromatic ring of the substrates 4a-k.

Synthesis of methyl 1-O-(4-hydroxymethamphetaminyl)-alpha-D-glucopyranouronate.

For the purpose of the direct characterization of the intact conjugated form in the urine of a methamphetamine (MA) abuser, 4-hydroxymethamphetamine (4-OHMA) glucuronate, corresponding to one of the metabolites of MA, was synthesized from the commercially available methyl 4-hydroxyphenylacetate.

Four cases of simultaneous triple primary cancers of the hypopharynx, esophagus, and stomach.

OBJECTIVE: To study the efficacy of intensive chemotherapy for simultaneous triple primary cancers of the hypopharynx, esophagus, and stomach. STUDY DESIGN: Retrospective case study. METHODS: From April 2000 to March 2002, we treated 4 patients who had simultaneous triple primary cancers, including hypopharyngeal, esophageal, and gastric carcinomas. These 4 patients were designated as the objects for analysis, and the treatment modality for simultaneous multiple primary cancer cases was examined. RESULTS: In 3 of 4 patients, all 3 primary cancers could be controlled by intensive induction chemotherapy and concurrent chemoradiotherapy for hypopharyngeal cancer and by endoscopic mucosal resection or argon plasma coagulation for esophageal and gastric carcinomas. CONCLUSIONS: In the treatment modality for simultaneous multiple primary cancers, including head and neck cancer, it is important to select intensive systemic chemotherapy and decide the order for treating each primary lesion in consideration of each patient's curability and prognosis.

Enzymatic resolution of (+/-)-5-acetoxy-4-aryl-(2E)-pentenoate derivatives.

Enzymatic resolution of six (+/-)-5-acetoxy-4-aryl-(2E)-pentenoate derivatives, compounds 9, 11, 13, 15, 17, and 19 bearing a different aromatic substitution pattern, using lipase OF-360 from Candida rugosa was carried out. The absolute configurations of all hydrolyzed products and all unchanged acetates were found to be S and R, respectively. Moreover, the enantiomeric excess of the enzymatic resolution products from 9, 11, and 13 with the ortho-methoxyl group in the aromatic ring was higher than that of the substrates with no methoxyl group at the ortho-position in the aromatic ring.

Pleomorphic adenoma of the lateral side of the tongue.

Pleomorphic adenoma is histopathologically the commonest tumor found in the major salivary glands. Pleomorphic adenoma originating from the tongue is very rare: only 26 cases have been reported in the world literature since 1960, only 2 of which originated from Ebner's gland. Herein we report the case of a 54-year-old female with pleomorphic adenoma of the tongue. The tumor was in contact with the molars. A partial glossectomy was performed with a surgical margin, as the preoperative pathological finding in the tissue specimen taken from the tumor was epithelial hyperplasia. The postoperative pathological diagnosis was pleomorphic adenoma with hyperplasia. It is unclear whether the teeth being in contact with the tumor caused tumorigenesis in this case. This case suggests that pleomorphic adenoma of the tongue originating from Ebner's gland should be considered in the differential diagnosis of lesions of the tongue.

Phase I trial of combined chemotherapy with docetaxel, cisplatin, and 5-fluorouracil for patients with locally advanced squamous cell carcinoma of the head and neck.

BACKGROUND: This phase I study was designed to determine the maximum tolerated dose (MTD) and toxicities of combination chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). METHODS: Patients received two cycles of chemotherapy repeated every 4 weeks. Starting doses (dose level 0) were: docetaxel 60 mg/m(2), cisplatin 60 mg/m(2), and 5-day continuous infusion 5-FU 600 mg/m(2) per day. At least three patients were examined at each dose level before advancing to the next level. RESULTS: Nineteen male patients (median age, 59.5 years) were enrolled. Eighteen patients had previously untreated stage III or IV SCCHN and 1 had local relapse, rT4. In the 19 patients, the regimen was well tolerated, with neutropenia as the most common toxicity (grade 3; n = 11; grade 4; n = 1). Dose-limiting toxicity (DLT) was observed at the fifth dose level (docetaxel 70 mg/m(2), cisplatin 70 mg/m(2), 5-FU 750 mg/m(2) per day), when 1 patient developed grade 2 renal toxicity during the first course; another 2 patients had persistent neutropenia. These doses were thus deemed the MTD for the regimen. In the 18 assessable patients, the overall clinical response rate was 94% (17/18 patients) and primary-site complete response (CR) occurred in 4 (22%) patients. CONCLUSION: The MTD of this regimen was docetaxel 70 mg/m(2) on day 1, cisplatin 70 mg/m(2) on day 4, and 5-FU 750 mg/m(2) per day for 5 days. The regimen was safe and generally well-tolerated and demonstrated good efficacy in patients with locally advanced SCCHN. This phase I study was designed to determine the maximum tolerated dose (MTD) and toxicities of combination chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN).

Midline prostatic cysts in healthy men: incidence and transabdominal sonographic findings.

OBJECTIVE: The purpose of this study was to use transabdominal sonography to investigate the incidence of midline prostatic cysts in healthy men. CONCLUSION: Midline prostatic cysts represent a common variant in asymptomatic men. In a patient with urologic symptoms, detection of a midline prostatic cyst requires a focused examination to determine whether the cyst represents a normal variant or is the cause of symptoms.

Total synthesis of (+)-macrosphelides A, C, E, F, and G based on enzymatic function.

The total synthesis of (+)-macrosphelide A (1) (18.5% overall yield in 11 steps), (+)-macrosphelide C (2) (25% overall yield in 9 steps), (+)-macrosphelide E (3) (23.9% overall yield in 11 steps), (+)-macrosphelide F (4) (20% overall yield in 9 steps), and (+)-macrosphelide G (5) (22% overall yield in 9 steps) was achieved from a chemoenzymatic reaction product (4R,5S)-4-benzyloxy-5-hydroxy-2(E)-hexenoate 10.

Intramolecular reaction of a phenonium ion. Novel lactonization of 4-aryl-5-tosyloxypentanoates and 4-aryl-5-tosyloxyhexanoates concomitant with a phenyl rearrangement.

The novel lactonizations of methyl 4-aryl-5-tosyloxypentanoate 1 and 4-aryl-5-tosyloxyhexanoate 3 concomitant with a phenyl rearrangement are reported. The lactonizations were promoted by silica gel or heating in various solvents. By examining the effects of substituents of the aromatic ring on the reactivity, it was found that the reaction proceeded via a phenonium ion. This finding was supported by the stereochemical results for the lactonization of optical active 1. Silica gel-promoted lactonization of 1 gave only gamma-lactone 2, whereas that of 3 afforded gamma-lactone 4 and delta-lactone 5. These lactonizations proved to be kinetically controlled. On the other hand, when 3c was heated in CH(3)NO(2) at 70 degrees C, the highly selective formation of 4c was observed. Further detailed experiments confirmed that the thermal lactonization in CH(3)NO(2) was thermodynamically controlled.

Formal total synthesis of (+)-macrosphelide A based on regioselective hydrolysis using lipase.

Three kinds of seco-macrosphelide A congeners, (4R,5S,10R,11S,15S)-6, (4R,5S,9S,14R,15S)-7 and (3S,8R,9S,14R,15S)-8 were chemically synthesized, and they were exposed to the lipase OF-360 from Candida rugosa to give three hydroxy carboxylic acids, respectively. Macrolactonization of the hydroxy acid (4R,5S,10R,11S)-18 derived from (4R,5S,10R,11S,15S)-6 gave 12-membered lactone (19) in 47% overall yield from 6, while that of the seco-acid (4) derived from (4R,5S,9S,14R,15S)-7 afforded (-)-dibenzyl macrosphelide A (25) in 27% overall yield from 7. Macrolactonization of the hydrolysis product, seco-acid (5) derived from (3S,8R,9S,14R,15S)-8, provided (-)-dibenzyl macrosphelide A (25) (5% overall yield from 8) and 12-membered lactone (19) (20% overall yield from 8) concurrently.

Determination of the absolute stereostructure of seco-macrosphelide E produced by a fungal strain from a sea hare.

seco-Macrosphelide E has been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai. Its absolute stereostructure, with the same configuration as that of macrosphelide E, have been elucidated on the basis of spectroscopic analyses and unambiguous synthesis.