Synthesis and Evaluation of FICA Derivatives as Chiral Derivatizing Agents.

1-Fluoroindan-1-carboxyic acid (FICA) derivatives containing a monosubstituted benzene ring (1b-e) were synthesized as their methyl esters and their potential as chiral derivatizing agents (CDAs) were assessed by both 19F- and 1H-NMR spectroscopy. Introduction of a substituent at the 4-position in the benzene ring caused a 1.2-2 fold increase in ΔδF values when compared with that of FICA. This increase was investigated using a correlation model for 19F-NMR and by the order of the stability of the synperiplanar (sp) and antiperiplanar (ap) conformers of the (R,S) and (S,S) diastereomers from the Gibbs' free energy at 298.15 K.

Determination of the Absolute Configuration of the Nabumetone Metabolite 4-(6-Methoxy-2-naphthyl)butan-2-ol Using the Chiral Derivatizing Agent, 1-Fluoroindan-1-carboxylic Acid.

The absolute configuration of (+)-4-(6-methoxy-2-naphthyl)butan-2-ol ((+)-MNBO), a nabumetone metabolite, was determined using 1-fluoroindan-1-carboxylic acid (FICA). Both enantiomers of the FICA methyl esters were derivatized to diastereomeric esters of (+)-MNBO by an ester exchange reaction. The results of 1H- and 19F-NMR spectroscopy of the diastereomeric FICA esters of (+)-MNBO confirmed the absolute configuration of (+)-MNBO was (S).

Improved synthetic route to methyl 1-fluoroindan-1-carboxylate (FICA Me ester) and 4-methyl derivatives.

An improved synthetic route has been developed for the preparation of methyl 1-fluoroindan-1-carboxylate (FICA Me ester) from 1-indanone. Methyl 4-methyl-1-fluoroindan-1-carboxylate (4-Me-FICA Me ester) was also prepared following the same procedure.

[An example of self-evaluation of a sense of achievement by students in 6-year pharmacy school with the model core curriculum of pharmaceutical education].

In March 2012, the first students, finishing the newly introduced 6-year-course of pharmaceutical education, have graduated and gone out into the world. At this point, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) is going to revise the model core curriculum of pharmaceutical education to be more suited for educating students to achieve their goal of becoming the clinical pharmacist standard defined by the revised School Education Act. Here we report the self-evaluation study based on the survey using questionnaire about a sense of achievement with Visual Analog Scales, regarding the fundamental quality as a pharmacist standard proposed by the Professional Activities Committee in the MEXT. The sample size of survey was about 600 of students studying in the Faculty of Pharmaceutical Sciences in Josai International University (JIU) and the survey was carried out during the period of March-April in 2012. The study suggested that the majority of graduates were satisfied with the new education system and marked as a well-balanced quality to be a pharmacist standard, after completing the 6-year pharmaceutical education based on "the model core-curriculum". It would be worthwhile to perform this kind of survey continuously to monitor the student's self-evaluation of a sense of achievement to verify the effectiveness of 6-year-course pharmaceutical education based on the newly establishing core curriculum in Japan.

Tumor-specific cytotoxicity and type of cell death induced by naphtho[2,3-b]furan-4,9-diones and related compounds in human tumor cell lines: relationship to electronic structure.

A total of thirty-nine naphtho[2,3-b]furan-4,9-diones and related compounds were tested for their cytotoxicity against three human normal oral cells (gingival fibroblast, HGF, pulp cell, HPC, periodontal ligament fibroblast, HPLF) and four human tumor cell lines (oral squamous cell carcinoma HSC-2, HSC-3, HSC-4, promyelocytic leukemia HL-60). 2-Acetylnaphtho[2,3-b]furan-4,9-dione [1] was highly cytotoxic to both normal and tumor cells, yielding low tumor-specificity. 2-Acetyl-4,9-dimethoxynaphtho[2,3-b]furan [4], the 2-(3-furanoyl) benzoic acids [5, 6] and the 1,4-naphthoquinones [7, 8] showed much reduced cytototoxicity and low tumor-specificity. The introduction of phenoxy [18], isopropylamino [23] or 2-methylpiperidino [33] groups to the 2-position of naphtho[2,3-b]furan-4,9-dione yielded compounds that showed the greatest tumor-specificity. These compounds, at twice or four times higher concentrations than CC50, induced the activation of caspase-3, caspase-8 and caspase-9 in the HSC-2 and HL-60 cells, but not so apparently in the HSC-4 cells. However, they did not induce internucleosomal DNA fragmentation in the HSC-2 and HSC-4 cells even after 24 hours incubation and only slightly induced DNA fragmentation in the HL-60 cells. Compound [18] induced the production of annexin-positive cells, but did not induce microtubule-associated protein light chain 3 (LC3) accumulation in autophagosomes in LC3-green fluorescent protein (GFP)-transfected HSC-2 cells. These data suggested that naphtho[2,3-b]furan-4,9-diones may induce the early apoptotic marker, without induction of caspase activation and DNA fragmentation in oral squamous cell carcinoma cell lines. Quantitative structure-activity relationship (QSAR) analysis suggests the applicability of the theoretical calculations such as frontier molecular orbital, dipole moments and hydrophobicity in predicting their cytotoxic activity.

Spongipyran Synthetic Studies. Evolution of a Scalable Total Synthesis of (+)-Spongistatin 1.

Three syntheses of the architecturally complex, cytotoxic marine macrolide (+)-spongistatin 1 (1) are reported. Highlights of the first-generation synthesis include: use of a dithiane multicomponent linchpin coupling tactic for construction of the AB and CD spiroketals, and their union via a highly selective Evans boron-mediated aldol reaction en route to an ABCD aldehyde; introduction of the C(44)-C(51) side chain via a Lewis acid-mediated ring opening of a glucal epoxide with an allylstannane to assemble the EF subunit; and final fragment union via Wittig coupling of the ABCD and EF subunits to form the C(28)-C(29) olefin, followed by regioselective Yamaguchi macrolactonization and global deprotection. The second- and third- generation syntheses, designed with the goal of accessing one gram of (+)-spongistatin 1 (1), maintain both the first-generation strategy for the ABCD aldehyde and final fragment union, while incorporating two more efficient approaches for construction of the EF Wittig salt. The latter combine the original chelation-controlled dithiane union of the E- and F-ring progenitors with application of a highly efficient cyanohydrin alkylation to append the F-ring side chain, in conjunction with two independent tactics to access the F-ring pyran. The first F-ring synthesis showcases a Petasis-Ferrier union/rearrangement protocol to access tetrahydropyrans, permitting the preparation of 750 mgs of the EF Wittig salt, which in turn was converted to 80 mg of (+)-spongistatin 1, while the second F-ring strategy, incorporates an organocatalytic aldol reaction as the key construct, permitting completion of 1.009 g of totally synthetic (+)-spongistatin 1 (1). A brief analysis of the three syntheses alongside our earlier synthesis of (+)-spongistatin 2 is also presented.

Preparation of 1,8-di-O-alkylaloe-emodins and 15-amino-, 15-thiocyano-, and 15-selenocyanochrysophanol derivatives from aloe-emodin and studying their cytotoxic effects.

1,8-di-O-alkylaloe-emodin derivatives (namely, methyl-, propyl-, hexyl-, dodecyl-, and octadecyl) were synthesized from naturally occurring aloe-emodin. Further, derivatives having various substituents such as diethylamino, pyrrolidinyl, piperidinyl, methylpiperazinyl, imidazolyl, thiocyano and selenocyano groups at the 15 position of chrysophanol and 1,8-di-O-hexylchrysophanol from aloe-emodin were synthesized. The cytotoxic effects of these derivatives on less P-glycoprotein (P-gp)-expressing HCT 116 cells and stably P-gp-expressing Hep G2 cells were evaluated by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among these products, several of them exhibited markedly higher potent cytotoxic effects not only on HCT116 cells but also Hep G2 cancer cells as compared to aloe-emodin.

Comparison of the cytotoxic activities of naturally occurring hydroxyanthraquinones and hydroxynaphthoquinones.

Seven hydroxyanthraquinone derivatives, 1-7, were isolated from the root of Rheum palmatum (Polygonaceae). Two propionated anthraquinone derivatives, 8 and 9, were synthesized. Four hydroxynaphthoquinone derivatives, 13, 14, 16 and 21, were isolated from the root of Lithospermum erythrorhizon Sieb. et Zucc. (Boraginaceae) and also three naphthoquinone derivatives, 19, 22 and 23, were isolated from the root of Macrotomia euchroma (Royle) Pauls. (Boraginaceae). The cytotoxicity of the anthraquinone and naphthoquinone derivatives on P-gp-underexpressing HCT 116 cells and P-gp-overexpressing Hep G2 cells was examined by MTT assay. Among the anthraquinone derivatives, compounds 3-5 which had OH, CH(2)OH and COOH substituent groups on the anthraquinone skeletons, respectively, showed potent growth inhibitory activities against both types of cancer cells (IC(50) values: 5.7+/-0.9 to 13.0+/-0.7 microM in the case of HCT 116 cells and 5.2+/-0.7 to 12.3+/-0.9 microM in the case of Hep G2 cells). All hydroxynaphthoquinone derivatives isolated in this study exhibited extremely potent growth inhibitory activities against both types of cancer cells (IC(50) values: 0.3+/-0.09 to 0.46+/-1.0 microM in the case of HCT 116 cells and 0.22+/-0.03 to 0.59+/-0.06 microM in the case of Hep G2 cells) as well as shikonin 10 (IC(50) values: 0.32+/-0.02 microM in the case of HCT 116 cells and 0.24+/-0.03 microM in the case of Hep G2 cells).

Cytotoxic activity toward KB cells of 2-substituted naphtho[2,3-b]furan-4,9-diones and their related compounds.

We investigated the cytotoxic activity of 2-substituted naphtho[2,3-b]furan-4,9-diones. We have previously synthesized 33 types of 2-substituted and related compounds, and the cytotoxic activity of these compounds was then examined by a KB cell culture assay. 2-(3-Furanoyl)benzoic acids and 1,4-naphthoquinones had no activity. 2-Acetyl-4,9-dimethoxynaphtho[2,3-b]furan 4 showed low activity. However, parent naphtho[2,3-b]furan-4,9-dione 2 and most 2-substituted derivatives exhibited cytotoxic activity. The parent structure was therefore for cytotoxicity. 2-Formylnaphtho[2,3-b]furan-4,9-dione 11 had particularly potent activity (ED50=0.09 microg/ml).

Reactions of 26-iodopseudodiosgenin and 26-iodopseudodiosgenone with various nucleophiles and pharmacological activities of the products.

26-Iodopseudodiosgenin (8) and 26-iodopseudodiosgenone (9) were reacted with various nucleophiles (KSCN, KOCN, NaCN, NaN(3) and various amines) to give pseudodiosgenin derivatives (4, 12, 16-20, 26) and pseudodiosgenone derivatives (5, 13, 21-25, 27), respectively. The reactions of 8 and 9 with KOCN gave the elimination products (10) and (11), respectively. The reaction of 9 with NaCN gave 5alpha,26- (14) and 5beta,26-dicyanocholestan-3-one (15). The reaction of 8 with NaN3 gave triazepine derivative (30), while that of 9 gave 26-azidopseudodiosgenone (31). Compound 31 was converted into triazepine derivative (32) by heating at 120 degrees C. The cytotoxicity of the pseudodiosgenins and pseudodiosgenones on P-gp-underexpressing HCT 116 cells and P-gp-overexpressing Hep G2 cells was examined by MTT assay. Pseudodiosgenins 2, 4, 12 and 30 showed strong cytotoxic activity (IC50 values: 2.6+/-0.3-6.7+/-1.4 microM), as did pseudodiosgenones 3, 5, 11, 13, 21-25 and 27 (IC50 values: 1.3+/-0.3-6.4+/-0.3 microM) toward HCT 116 cells. Pseudodiosgenins 12, 16 and 30 (IC50 values: 1.2+/-0.7-2.2+/-0.6 microM) and pseudodiosgenones 22, 23, 25 and 27 (IC50 values: 0.6+/-0.1-2.5+/-0.3 microM) were highly cytotoxic to Hep G2 cells. Compounds 3 and 27 showed efficient antibacterial activity (MIC: 15.6, 10.4 microg/ml) and (MIC: 7.8, 15.6 microg/ml) against Bacillus subtilis and Staphylococcus aureus, respectively.

Preparations of vitamin D analogs, spirostanols and furostanols from diosgenin and their cytotoxic activities.

Vitamin D analogs 12 and 13 having a spiro ring in the side chain, various spirostanols 18-21, 26, 27, 29 and 37, and furostanols 34-36 having SCN and SeCN groups at the 26 position were prepared from diosgenin 1 via (20S,22R,25R)-spirost-1alpha,2alpha-epoxy-4,6-dien-3-one 19 as a key intermediate. The cytotoxic activities of these derivatives as well as 1 on scarcely P-gp-expressed HCT 116 cells and P-gp-overexpressed Hep G2 cells were examined by MTT assay. Furostanols 34 (IC(50) value: 4.9+/-0.3 microM) and 36 (IC(50) value: 1.3+/-0.2 microM) exhibited marked cytotoxic effects on HCT 116 cells, and spirostanol 29 (IC(50) value: 2.4+/-0.8 microM) and furostanol 36 (IC(50) value: 2.8+/-0.4 microM) on Hep G2 cells. Furthermore, the effects of vitamin D analog 12, spirostanol 26 and furostanol 36 on apoptosis-signaling pathways were investigated. Compounds 12 and 26 overexpressed p53 and Bax mRNAs, while compound 36 overexpressed only Bax mRNA.

4'-O-Alkyaloenin derivatives and their sulfates directed toward overcoming multidrug resistance in tumor cells.

The cytotoxic effects on HCT 116, Hep G2 and HCT 116/VCR 100-1-1 cell lines of synthetic 4'-O-alkylaloenins (2-17), 4'-O-benzylaloenin (18) and 4'-O-allylaloenin (19) were examined by MTT assay, and compared with that of aloenin (1) isolated from Aloe arborescens Mill. Var. natalensis Berger which showed no marked effect (IC50 value: > 100 microM). The cytotoxic effects of 4'-O-alkylaloenin sulfates (21-29) were also examined on the same cell lines. The introduction of a longer alkyl group at the O-4' position of 1 resulted in a higher cytotoxic action on HCT 116 and Hep G2 cells. Among 4'-O-alkylaloenins 2-17, 4'-O-tetradecylaloenin 14 was the most cytotoxic to both on HCT 116 cells (IC50 value: 5.3+/-2.3 microM) and Hep G2 cells (IC50 value: 4.0+/-0.6 microM). Also among 4'-O-alkylaloenin sulfates 21-29, 4'-O-dodecylaloenin sulfate 29 was the most cytotoxic to both on HCT 116 (IC50 value: 4.8+/-0.2 microM) and Hep G2 cells (IC50 value: 4.0+/-0.5 microM). 4'-O-Alkylaloenins 7-14 and 4'-O-alkylaloenin sulfates 24-29 were also cytotoxic to Hep G2 and HCT 116/VCR 100-1-1 cell lines, which overexpress P-glycoprotein, as well as HCT 116 cell lines which scarcely express it.

Preparations of heterospirostanols and their pharmacological activities.

(3beta,20S,22S,25R)-22-Thiospirosol-5-en-3-ol (9) and (3beta,20S,22S,25R)-22-seleno-spirosol-5-en-3-ol (11) were prepared from diosgenin (3) via 26-iodopseudodiosgenin (6) as a key intermediate. Diosgenone (15), solasodinone (16), (20S,22S,25R)-22-thio-spirosol-4-en-3-one (17), (20S,22S,25R)-22-selenospirosol-4-en-3-one (18) and (20R,22S,25R)-spirosol-4-en-3-one (19) were prepared by Oppenauer oxidation of 3, solasodine 4, 9, 11 and (3beta,20R,22R,25R)-spirosol-5-en-3-ol 14, respectively. Oxidations of 15 and 16 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) provided corresponding dienone products, (20S,22S,25R)-spirosol-1,4-dien-3-one (20) and (20S,22S,25R)-22-thiospirosol-1,4-dien-3-one (21), respectively, while oxidation of 19 (C-20 diastereoisomer of 15) gave no dienone product but 21-exo vinyl product 22. 26-Thioacetylpseudodiosgenone (24) and 26-cyanoselenopseudodiosgenone (25) were prepared by treatment of 26-iodopseudodiosgenose (23), which was obtained by Oppenauer oxidation of 6, with potassium thioacetate and potassium selenocyanate, respectively. Compounds 15 and 19 exhibited more than 80% inhibitions in INF-gamma productions at 10.0 microM. Compounds 4 and 25 showed cytotoxic activities (IC(50) = 6 and 5 microM, respectively) against cancerous HCT 116 cell lines. Compounds 12 and 25 had antiurease activities (IC(50) = 12.4 and 11.4 microM, respectively), in which only the latter showed an inhibition zone (mean zone diameter = 12.2 mm) formed by Bacillus subtilis 168 trp.

Spongistatin synthetic studies. An efficient, second-generation construction of an advanced ABCD intermediate.

[reaction: see text] A short, efficient, and stereocontrolled synthesis of (-)-4, an advanced ABCD subunit of the spongistatins, has been achieved. Central to the synthetic strategy is the multicomponent linchpin union of silyl dithianes with epoxides to access both the AB and CD fragments. Fragment coupling was then achieved via an efficient stereoselective aldol reaction. The linear sequence required 22 steps and proceeded in 4.0% overall yield.