In early studies, we have reported the antinociceptive profile of (−)-spectaline, a piperidine alkaloid from Cassia spectabilis. The present study describes the synthesis, the antinociceptive and anti-inflammatory activities of a series of 2,3,6-trialkyl-piperidine alkaloids: the natural (−)-3-O-acetyl-spectaline (LASSBio-755) and ten semi-synthetic spectaline derivatives. Structure–activity relationship (SARs) studies were performed. The structures of all synthesized derivatives were confirmed by means of nuclear magnetic resonance. Compounds were evaluated for their analgesic (acetic acid-induced mouse abdominal constrictions, hot-plate test, formalin-induced pain test) and some of them for the anti-inflammatory activities (carrageenan-induced rat paw edema test). The pharmacological results showed that several of the new compounds given orally at a dose of 100 μmol/kg significantly inhibited the acetic acid-induced abdominal constrictions, but they were less active than (−)-spectaline. LASSBio-755 and LASSBio-776 were the most actives with 37% and 31.7% of inhibition. In the formalin-induced pain only LASSBio-776 was able to inhibit by 34.4% the paw licking response of the inflammatory phase, (−)-spectaline and LASSBio-755 did show any activity. In the carrageenan-induced rat paw edema, only (−)-spectaline exhibited an anti-inflammatory profile, showing an ED₅₀ value of 56.6 μmol/kg. Our results suggest different mechanisms of action for the analgesic activity observed for LASSBio-776 (3-O-Boc-spectaline), LASSBio-755 (3-O-acetyl-spectaline) and (−)-spectaline (LASSBio-754). The antinociceptive profile of some of the semi-synthetic spectaline derivatives extends our research concerning the chemical and pharmacological optimization of isolated natural products in the search of new drug candidates from brazilian biodiversity.

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The present study describes the development and subsequent validation of a stability indicating reverse-phase HPLC (RP-HPLC) method for the analysis of oseltamivir active pharmaceutical ingredient (API). The proposed RP-HPLC method utilizes Kromasil C₁₈, 5 μm, 250 mm×4.6 mm i.d. column (at ambient temperature), gradient run (using acetonitrile and triethylamine as mobile phase), effluent flow rate (1.0 ml/min), and UV detection at 215 nm for analysis of oseltamivir. The described method was linear over the range of 70—130 μg/ml (r²=0.999). The precision, ruggedness and robustness values were also within the prescribed limits (<1% for system precision and <2% for other parameters). Oseltamivir was exposed to acidic, basic, oxidative and thermal stress conditions, and the stressed samples were analyzed by the proposed method. Chromatographic peak purity results indicated the absence of co-eluting peaks with the main peak of oseltamivir, which demonstrated the specificity of assay method for estimation of oseltamivir in presence of degradation products. The proposed method can be used for routine analysis of oseltamivir in quality control laboratories.

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5,7-Dihydroxyflavone (chrysin) (1) when fermented with fungal cultures, Aspergillus alliaceous (ATCC 10060), Beauveria bassiana (ATCC 13144) and Absidia glauco (ATCC 22752) gave mainly 4′-hydroxychrysin (4), chrysin 7-O-β-D-4-O-methylglucopyranoside (5) and chrysin 7-sulfate (6), respectively. Mucore ramannianus (ATCC 9628), however, transformed chrysin into six metabolites: 4′-hydroxy-3′-methoxychrysin (chrysoeriol) (7), 4′-hydroxychrysin (apigenin) (4) 3′,4′-dihydroxychrysin (luteolin) (8), 3′-methoxychrysin 4′-O-α-D-6-deoxyallopyranoside (9), chrysin 4′-O-α-D-6-deoxyallopyranoside (10), and luteolin 3′-sulfate (11). Cultures of A. alliaceous (ATCC 10060) and B. bassiana (ATCC 13144) metabolized 5-hydroxyflavone (2) into 5,4′-dihydroxyflavone (12) and 4′-hydroxyflavone 5-O-β-D-4-O-methylglucopyranoside (13), respectively. 6-Hydroxyflavone (3) was transformed into 6-hydroxyflavanone (14), flavone 3-O-β-D-4-O-methylglucopyranoside (15) and (±)-flavanone 6-O-β-D-4-O-methylglucopyranoside (16) by cultures of Beauveria bassiana (ATCC 13144). The structures of the metabolic products were elucidated by means of spectroscopic data. The significance of the metabolites as antioxidants in relation to their structure is briefly discussed.

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During a random screening of representative libraries of nucleoside analogues we discovered that the adenine derivatives FEVB28 and FEG118 were Flaviviridae inhibitors endowed with potency comparable, if not superior, to that of ribavirin. Those studies prompted us to design a new class of protected nucleoside analogs, reported herein, which displays interesting anti-bovine viral diarrhea virus (BVDV) activity and low cytotoxicity in cell-based assays (4, 23, 29 EC₅₀: 14, 11, 26 μM respectively, CC₅₀>100 μM) and appreciable activity in enzyme assays against the RNA dependent RNA polymerase (RdRp) of BVDV (4, 23, 29, RdRp inhibition activity 27, 16, 15 μM respectively). A molecular modeling study was also carried out to highlight the possible interactions between this compounds class and the corresponding hepatitis C virus (HCV) enzyme.

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Mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates 1 were easily prepared by the cyclodehydration reaction of N-acyl-N-alkyl-α-amino acids with trifluoroacetic anhydride. Due to the presence of the trifluoromethyl ketone and the mesoionic five-membered oxazole, there are three reaction sites to be attacked by the nucleophiles at C-2, C-5 and the trifluoroacetyl group in 1. Based on this model, three modes of regioselective attack by phenylhydrazine were found to provide three different products, i.e., 6-trifluoromethyl-1,2,4-triazines 3, 3-trifluoromethyl-5-pyrazolones 5 and 5-trifluoromethyl-3-hydroxypyrazoles 4, in good yields, respectively, depending on the nature of the solvent and reaction temperature. These three types of different reactions may be explained by the polarity of the reaction solvent and the mesoionic oxazole-ketene tautomerism.

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Six new dibenzofuran glycosides, fortuneanosides G (1), H (2), I (3), J (4), K (5), and L (6), were isolated from the fruit of Pyracantha fortuneana (MAXIM) LI. Their structures were determined to be 3,7-dihydroxy-2,4-dimethoxy-dibenzofuran 7-O-β-D-glucopyranoside, 3,7-dihydroxy-2,4-dimethoxy-dibenzofuran 7-O-(α-L-rhamnopyranosyl)-(1—6)-β-D-glucopyranoside, 3,6-dihydroxy-2,4-dimethoxy-dibenzofuran 6-O-β-D-glucopyranoside, 2,4-dimethoxy-3,6,9-trihydroxy-dibenzofuran 6-O-β-D-glucopyranoside, 3,9-dihydroxy-2,4-dimethoxy-dibenzofuran 3-O-β-D-glucopyranoside, and 2-methoxy-3,4,9-trihydroxy-dibenzofuran 4-O-β-D-glucopyranoside based on spectroscopic analysis. Fortuneanosides G—J showed more potent tyrosinase-inhibitory activity than arbutin.

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The interactions of kaempferol and quercetin with intravenous immunoglobulin (IVIG) were studied in vitro by spectroscopic methods including fluorescence spectra, Fourier transformation infrared (FT-IR) spectra and circular dichroism (CD) spectra. The binding parameters for the reactions calculated according to the Sips equation suggested that the bindings of IVIG to kaempferol and quercetin were characterized by two binding sites with the average affinity constants K_o at 1.032×10⁴ M⁻¹ and 1.849×10⁴ M⁻¹, respectively. The binding of IVIG with quercetin is stronger than that of IVIG with kaempferol. They were of non-specific and weak drug–protein interactions. Docking was used to calculate the interaction modes between kaempferol and quercetin with IVIG. The secondary structural compositions of free IVIG and its kaempferol, quercetin complexes were calculated by the FT-IR difference spectra, self-deconvolution, second derivative resolution enhancement and the curve-fitting procedures of amide I band respectively, which are in good agreement with the analyses of CD spectra. The effect of 3′-OH substituent in quercetin is distinct between the interactions of IVIG with kaempferol and quercetin for the secondary structure of the protein. The observed spectral changes indicate a partial unfolding of the protein structure, but the typical β structural conformation of IVIG is still retentive in the presence of both drugs in aqueous solution. The average binding distances between the chromophores of IVIG with kaempferol (4.30 nm) and quercetin (4.35 nm) were obtained on the basis of the theory of Förster energy transfer. IVIG can serve as transport protein (carrier) for kaempferol and quercetin.

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A new coumarin derivative (8-methylcoumaro-4a,10a-pyrone-3-carbaldehyde benzoyl hydrazone) ligand and its novel Cu(II) complex have been synthesized and characterized on the basis of elemental analyses, molar conductivities, ¹H-NMR, IR spectra, UV–visible spectroscopy and thermal analyses. In addition, the interactions of the Cu(II) complex and the ligand with calf-thymus DNA were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. It was found that both the two compounds, specially the Cu(II) complex, strongly bind with calf-thymus DNA, presumably via an intercalation mechanism.

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A novel time-controlled system based on elementary osmotic pump tablet containing a drug–resin complexes (DRCs) core is presented. In the traditional osmotic pump tablets (OPTs), the lag time was always minimized. On the contrary, in the DRCs osmotic pump tablet (DRCOPT), the lag time was increased to achieve time-controlled delivery. The system led to a zero-order drug release after an initial lag time. Polyethylene oxide (PEO) N80 was used as suspension agent and NaCl was applied as ion-exchange, osmotic pressure (electrolyte supplementary) agent, respectively. To examine the mechanism of this system, drug release behaviors were investigated under conditions of various osmotic pressures. A new method of combination of conductivity and HPLC was applied to determine the different fractions of NaCl in producing osmotic pressure, ion-exchange and electrolyte supplement. The pharmacokinetic studies conducted in beagle dogs showed that a steadier and controlled drug release behavior was obtained compared with the traditional formulations. On the basis of prescription of the DRCOPT, a good in-vitro–in-vivo correlation (IVIVC, R²=0.9541) was achieved. In addition, a lag time of 4 h was observed in in vivo experiment, which indicated that the DRCOPT can be used in therapeutic regimens with the characteristics of chronotherapy.

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The purpose of this study was to obtain a nicorandil pulsatile release tablet that has a well-regulated release lag time. When nicorandil is used as an antiangina drug, administration time control is important. A pulsatile release tablet is one of the effective approaches to modified release to reduce daily administration frequency. In this study, a pulsatile release tablet of nicorandil was formulated by fumaric acid dry coating around the core tablet including nicorandil. The model tablets, which had different content ratios of excipients in the dry-coating layer, were characterized by a dissolution test. The results showed that the release lag time was generated with fast release profiles. Various lag time controls of tablets were achieved, from 60 to 310 min on average, by variation of outer layer composition. From an analysis of the relation between lag times and outer layer composition, the key ingredient for prolongation of lag time was found to be fumaric acid. To analyze the lag time generation mechanism, water penetration for tablet was measured. The results indicated that the penetration depth was proportionate to the square root of time and the lag time formation mechanism was simple water penetration through the matrix of fumaric acid to the tablet core. The results also showed that the Washburn equation could be used to design the lag time of the pulsatile release tablet in this study. In conclusion, novel release control technology using fumaric acid was appropriate to obtain a nicorandil pulsatile release tablet that has well regulated lag time.

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Intermolecular interactions of α-, β-, γ- and heptakis(2,6-di-O-methyl)-β-cyclodextrin (CD) with syringic acid (Syr) in aqueous solution are investigated by fluorescence spectroscopy. The fluorescence intensity of Syr gradually increases with the addition of the CDs. The formation constants (K) of the host–guest inclusion complexes are determined using a nonlinear analysis. The association abilities of Syr with the CDs decrease in the order γ->β->α-<DMβ-CD. Both the intrinsic binding abilities of the CDs and the structural effect of Syr are taken into consideration when comparing the K values. Based on the results of NMR experimental and theoretical PM3 calculations both in vacuo and in water, it is found that Syr stays near the wider rim of α-CD cavity. Both the number of substituted groups (NSG) in a guest and the molar volume ratio of the guest to host cavity (MVR) play an important role in forming the CD supramolecular complexes of a homologous series of phenol derivatives, such as 2-methoxylphenol (2-Mop), eugenol (Eug) and Syr, i.e., an appropriate NSG or MVR in an inclusion system, such as in 2-Mop–α-CD, Eug–β-CD and Syr–γ-CD systems, can maximize the intermolecular interaction between host and guest.

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The proposed method was developed for the determination of aluminum (Al) in large volume parenteral (LVP) drug products used in total parenteral nutrition (TPN) therapy. The determination of Al in LVP drug products was performed by an inductively coupled plasma mass spectrometer equipped with a dynamic reaction cell (DRC-ICP-MS). DRC-ICP-MS conditions for the analysis of Al were studied to obtain the best signal to background (S/N) ratios. The interfering polyatomic ions at mass 27 (Al) were reduced by using NH₃ as a reaction gas. The detection limit of Al in a 1% (v/v) HNO₃ aqueous solution was 2 ng/l. The Al contents in LVP drug products obtained by this method were in the range of 1.16—4.33 μg/l and were less than 25 μg/l, that is, the regulation value of Food and Drug Administration (FDA). In order to trace the origin of Al in LVP drug products, each part of the LVP drug product, which is composed of three chambers, was investigated. However, a clear difference of the Al contents in each chamber was not observed. Furthermore, the Al contents in injection bags were quantified. Although the Al contents in injection bags were relatively high (in the range of 27.5—33.6 μg/g), dissolution of Al from the injection bags was not observed in the stability testing. From all of these results, it was concluded that the Al contents in the LVP drug products investigated originated in the amount of the Al in each raw material.

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Diels–Alder reactions between N-phenylmaleimide, acting as the dienophile, and 2(1H)-pyridones having a methoxy or a chloro substituent, were carried out, under atmospheric and high pressure conditions, to give the corresponding isoquinuclidine derivatives. Stereoselectivity of the Diels–Alder reactions was studied using molecular orbital calculations.

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We evaluated the composition of Swertia herbs using high performance liquid chromatography-diode array detector-mass spectrometry (HPLC-DAD-MS). Eleven peaks of 6 species were unequivocally identified by comparing their retention times, UV spectra, on-line electrospray ionization mass (ESI-MS) spectra, and collision-induced dissociation mass spectrometry/mass spectrometry (CID-MS/MS) data with those of authentic compounds. We adopted wavelengths of 254 nm, 340 nm and 230 nm to simultaneously determine these 11 compounds. By comparing the overall DAD and total ion current (TIC) profiles of various samples, the 6 species were differentiated in terms of the occurrence and/or relative concentrations of the eleven compounds. Our novel validated HPLC-DAD-MS method not only facilitates quality control and identification of Swertia herbs, but is also applicable to systematic investigations of the distribution of secoiridoids, flavonoids, and xanthones in the genus Swertia.

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Investigation of the non-polar fraction of Boesenbergia pandurata of Myanmar led to the identification of six novel secondary metabolites, panduratins D—I (1—6), together with known diastereomers, panduratins B1 (7) and B2 (8). Their structures were determined based on extensive spectroscopic analysis. The in vitro preferential cytotoxicity of all isolates was examined against human pancreatic PANC-1 cancer cells under nutrient-deprived conditions. All exhibited a mild activity.

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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.

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The present investigation studied a novel extended release system of promethazine hydrochloride (PHC) with acrylic polymers Eudragit RLPO and Eudragit RS100 in different weight ratios (1 : 1 and 1 : 5) using coevaporation and coprecipitation techniques. Solid dispersions were characterized by Fourier-transformed infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), Powder X-ray diffractometry (PXRD), Nuclear magnetic resonance (NMR), Scanning electron microscopy (SEM) as well as solubility and in vitro dissolution studies in 0.1 n HCl (pH 1.2), double distilled water and phosphate buffer (pH 7.4). Adsorption test from drug solution to solid polymers were also performed. Selected solid dispersion system was subjected to direct compression and compressed tablets were evaluated for in vitro dissolution studies. The progressive disappearance of drug peaks in thermotropic profiles of coevaporates were related to increasing amount of polymers while SEM studies suggested homogenous dispersion of drug in polymer. Eudragit RLPO had a greater adsorptive capacity than Eudragit RS100 and thus its coevaporates in 1 : 5 ratio exhibited higher dissolution rate with 91.90% drug release for 12 h. Among different formulations, tablets prepared by Eudragit RLPO coevaporates (1 : 5) displayed extended release of drug for 12 h with 90.87% release followed by zero order kinetics (r²=0.9808).

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A new series of 2-substituted-5-[2-(2-halobenzyloxy)phenyl]-1,3,4-oxadiazoles was designed and synthesized as anticonvulsant agents. Electroshock and pentylenetetrazole-induced lethal convulsion tests showed that the introduction of an amino group at position 2 of 1,3,4-oxadiazole ring and a fluoro substituent at ortho position of benzyloxy moiety had the best anticonvulsant activity. Our results showed that this effect is mediated through benzodiazepine receptors mechanism.

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The mechanism of the electrochemical oxidation of 2,5-dihydroxybenzoic acid and 3,4-dihydroxybenzaldehyde in the presence of 3-hydroxy-1H-phenalene-1-one as a nucleophile has been studied in water/acetonitrile (80/20 v/v) solution using cyclic voltammetry and controlled-potential coulometry methods. The results indicate that the quinones derived from oxidation of 2,5-dihydroxybenzoic acid and 3,4-dihydroxybenzaldehyde participate in Michael addition reactions with 3-hydroxy-1H-phenalene-1-one and via ECE and ECEC mechanisms convert to the different products, with good yield under controlled potential conditions, at carbon electrode.

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Oral controlled release matrix tablets of zidovudine were prepared using different proportions and different viscosity grades of hydroxypropyl methylcellulose. The effect of various formulation factors like polymer proportion, polymer viscosity and compression force on the in vitro release of drug were studied. In vitro release studies were carried out using United States Pharmacopeia (USP) type 1 apparatus (basket method) in 900 ml of pH 6.8 phosphate buffer at 100 rpm. The release kinetics were analyzed using Zero-order model equation, Higuchi's square-root equation and Ritger–Peppas' empirical equation. Compatibility of drug with various formulations excipients used was studied. In vitro release studies revealed that the release rate decreased with increase in polymer proportion and viscosity grade. Increase in compression force was found to decrease the rate of drug release. Matrix tablets containing 10% hydroxypropyl methylcellulose (HPMC) 4000 cps were found to show a good initial drug release of 21% in the first hour and extended the release upto 16 h. Matrix tablets containing 20% HPMC 4000 cps and 10% HPMC 15000 cps showed a first hour release of 18% and extended the release upto 20 h. Mathematical analysis of the release kinetics indicated that the nature of drug release from the matrix tablets followed non-Fickian or anomalous release. No incompatibility was observed between the drug and excipients used in the formulation of matrix tablets. The developed controlled release matrix tablets of zidovudine, with good initial release (17—25% in first hour) and which extend the release upto 16—20 h, can overcome the disadvantages of conventional tablets of zidovudine.

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In the pharmaceutical preparation of a controlled release drug, it is very important and necessary to understand the release properties. In previous papers, a combination of the square-root time law and cube-root law equations was confirmed to be a useful equation for qualitative treatment. It was also confirmed that the combination equation could analyze the release properties of layered granules as well as matrix granules. The drug release property from layered granules is different from that of matrix granules. A time lag occurs before release, and the entire release property of layered granules was analyzed using the combination of the square-root time law and cube-root law equations. It is considered that the analysis method is very useful and efficient for both matrix and layered granules. Comparing the granulation methods, it is easier to control the manufacturing process by tumbling granulation (method B) than by tumbling-fluidized bed granulation (method C). Ethylcellulose (EC) layered granulation by a fluidized bed granulator might be convenient for the preparation of controlled release dosage forms as compared with a tumbling granulator, because the layered granules prepared by the fluidized bed granulator can granulate and dry at the same time. The time required for drying by the fluidized bed granulator is shorter than that by the tumbling granulator, so the fluidized bed granulator is convenient for preparation of granules in handling and shorter processing time than the tumbling granulator. It was also suggested that the EC layered granules prepared by the fluidized bed granulator were suitable for a controlled release system as well as the EC matrix granules.

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In this study, the taste-masking of famotidine, which could apply to any fast-disintegrating tablet, was investigated using the spray-dry method. The target characteristics of taste-masked particles were set as follows: the dissolution rate is not to be more than 30% at 1 min and not less than 85% at 15 min, and the particle size is not to be more than 150 μm in diameter to avoid a gritty feeling in the mouth. The target dissolution profiles of spray-dried particles consisting of Aquacoat ECD30 and Eudragit NE30D or triacetin was accomplished by the screening of formulas and the appropriate lab-scale manufacturing conditions. Lab-scale testing produced taste-masked particles that met the formulation targets. On the pilot scale, spray-dried particles with attributes, such as dissolution rate and particle size, of the same quality were produced, and reproducibility was also confirmed. This confirmed that the spray-dry method produced the most appropriate taste-masked particles for fast-disintegrating dosage forms.

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Five new glycosides, creosides I, II, III, IV, and V, were isolated from the methanolic extract of the roots of Rhodiola crenulata, together with 21 known compounds. The chemical structures of new constituents were elucidated on the basis of chemical and physicochemical evidence.

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A new ligand, 1-cyclohexyl-3-tosylurea (H₂L), was prepared by condensation ethyl N-(3-tossulfonyl) carbamate and cyclohexanamine. Its two lanthanide(III) complexes, Ln(H₂L)₃·3NO₃ [Ln=Nd (1), and Eu (2)], have been synthesized and characterized on the base of element analyses, ESI-MS, molar conductivities, IR spectra and thermogravimetry/differential thermal analysis (TG-DTA). In addition, the DNA-binding properties of the ligand and its complexes have been investigated by electronic absorption spectroscopy, fluorescence spectroscopy, circular dichroic (CD) spectroscopy and viscosity measurements. The experiment results suggest that the ligand and its two complexes bind to DNA via a groove binding mode, and the binding affinity of the complex 2 is higher than that of the complex 1 and the ligand. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the ligand and its metal complexes was determined by using spectrophotometer methods in vitro. These complexes were found to possess potent antioxidant activity and be better than standard antioxidants like vitamin C and mannitol. In particular, complex 2 displayed excellent activity on the superoxide and hydroxyl radical.

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Following the investigation of foliasalaciosides A₁, A₂, B₁, B₂, C, and D, seven new megastigmane glycosides named foliasalaciosides E₁—I (1—7), together with four known constituents, were isolated from the leaves of Salacia chinensis LINN. collected in Thailand. The absolute stereostructures of the new compounds were characterized on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method.

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In the previous work we reported five A-seco-rearranged lanostane triterpenoids as antibacterial constituents from the ethyl acetate soluble fraction of Abies sachalinensei leaves. In further study on the isolation of constituents from the ethyl acetate soluble fraction, two new rearranged lanostane and lanostane-type triterpenoids (3, 4) and three reported compound (1, 2, 5) were isolated. The structures of new compound 3 and 4 were determined to be 3,4-seco-4(28),6,8(14),24-mariesatetraen-26,23-olide-23-hydroxy-3-oic acid and 3,4-seco-4(28),7,24-lanostatrien-26,23-olide-23-hydroxy-3-oic acid, respectively, by spectral studies on HR-MS, ¹H-NMR, ¹³C-NMR, and 2D-NMR spectra. Compound 1 was identified with pindrolactone and its structure was revised as 7,14,22Z,24-mariesatetraen-26,23-olide-3α-ol. Structures of 2 and 5 were determined as 7,14,24-mariesatrien-26,23-olide-3α,23-diol and 3α-hydroxy-7,14,24E-mariesatrien-23-oxo-26-oic acid. Of these compounds, 2, 3 and 4 were obtained as lactol tautomer mixtures at γ-lactone structures of side chains.

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Six new acylated oleanane-type triterpene oligoglycosides, perennisaponins A (1), B (2), C (3), D (4), E (5), and F (6), were isolated from the flowers of Bellis perennis (Daisy flower) together with 14 saponins, nine flavonoids, and two glycosides. The structures of 1—6 were elucidated on the basis of chemical and physicochemical evidence.

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To improve its solubility, dissolution, and bioavailability; Ibuprofen–polyethylene glycol 8000 (PEG 8000) solid dispersions (SDs) with different drug loadings were prepared, characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), and evaluated for solubility, in-vitro release, and oral bioavailability of ibuprofen in rats. Loss of individual surface properties during melting and solidification as revealed by SEM micrographs indicated the formation of effective SDs. Absence or shifting towards the lower melting temperature of the drug peak in SDs and physical mixtures in DSC study indicated the possibilities of drug–polymer interactions. Quicker release of ibuprofen from SDs in rat intestine resulted in a significant increase in AUC and C_max, and a significant decrease in T_max over pure ibuprofen. Preliminary results of this study suggested that the preparation of ibuprofen SDs using PEG 8000 as a meltable hydrophilic polymer carrier could be a promising approach to improve solubility, dissolution and bioavailability of ibuprofen.

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Telmisartan (anti-hypertensive) is insoluble in water; hence the drug may be slowly or incompletely dissolved in the gastro intestinal tract. So the rate of dissolution and therefore its bioavailability is less (bioavailability 42%). In the present study an attempt has been made to prepare immediate release tablets of telmisartan by using Polyplasdone XL-10 (Crosspovidone) at intragranular, extragranular and partly intra and extragranular level of addition to increase the rate of drug release from dosage form to increase the dissolution rate and hence its bioavailability. The prepared granules and tablets were evaluated for their physiochemical properties and in-vitro dissolution study was conducted for the prepared tablets. It was concluded that the immediate release tablets with proper hardness, disintegration time and with increase rate of dissolution can be made using Polyplasdone XL-10. Formuation-10 (F10) was selected for stability study and the in-vitro dissolution study showed that was no difference in percent of drug released between initial and sixth month sample.

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Sorbic acid (SA: CH₃–CH=CH–CH=CH–COOH) and its salts are widely used as preservatives in foodstuff because of their growth inhibitory effects on mold, yeast and a wide range of bacteria. However, it is still unclear whether SA and its salts are actually incorporated in these organisms and a higher organisms like mammalian cells. Acidic compounds such as SA are usually analyzed by HPLC with eluents containing acetic acid, formic acid and their ammonium acetates, but such acidic buffers may suppress the ionization efficiency of the acidic compounds in negative-mode electrospray ionization (ESI). In this study, we present a sensitive and simple method for analysis of SA by HPLC with non-acidic solvents such as CH₃CN/CH₃OH–H₂O by negative ion mode ESI-LC/MS. As a result, SA at less as 30 fmol was selectively determined by the selected reaction monitoring (SRM) mode. It was defined as the peak area with a signal-to-noise ratio (S/N) of 3. Good linearity was obtained in the range from 55 fmol (S/N 3) to 500 fmol (r²=0.9968) for SA by using LC/MS with the SRM mode. We also show that the method is useful to analyze SA level in the cytosol of mastocytoma cells, which were pretreated with SA. These results suggest the applicability of this method for the highly sensitive determination of SA in the mammalian tissues and cells.

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Paprika and pimiento are used as vegetables and spices. We have obtained three new acyclic diterpene glycosides, called capsianosides XVII (1), V methyl ester (2) and XIV (3) together with capsianosides I¹⁾ and II²⁾ from the aerial parts of paprika and pimiento. The structures of these compounds have been established by ¹H- and ¹³C-NMR spectra and two-dimensional NMR methods.

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A new diterpene, 16-hydroxy communic acid (1), along with thirty one known compounds including five norditerpenes (2—6), twenty two flavonoids containing four biflavonoids (7—10), nine monoflavonoids (11—19) and nine flavanoid glycosides (20—28), as well as four phenolic constituents (29—32) were isolated from the 95% ethanolic extract of Podocarpus fasciculus. The structure of 1 was elucidated using spectral methods. Of these isolates, nagilactone C (2) showed the most significant inhibitory effects against DLD cells (human colon carcinoma) (ED₅₀=2.57 μg/ml) and compounds 7, 8, 10, 11, and 12 had moderate cytotoxic activity against human KB (human oral epithelium carcinoma), Hela (human cervical carcinoma), Hepa (human hepatoma), DLD (colon carcinoma), and A-549 (human lung carcinoma) tumor cell lines. Preliminary structure–activity relationship studies of the isolated diterpenoids and biflavonoids are discussed.

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Two new bis-coumarin glycosides were isolated from the stem barks of Daphne giraldii NITSCHE. Their structures were elucidated as 6-O-α-L-rhamnnopyranosyl daphnogirin (1), and 6-O-β-D-apiofuranosyl daphnogirin (2), on the basis of detailed spectroscopic analysis. Compounds 1 and 2 were tested inhibitory effects against production of nitric oxide (NO) in RAW264.7 cells, and cytotoxicity of human tumor cell lines A549, LOVO, QGY-7703, 6T-CEM. The results showed that compounds 1 and 2 neither reduced production of NO, nor inhibited human tumor cell lines.

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Three new flavonoid glycosides, eriodictyol 7-O-(6″-feruloyl)-β-D-glucopyranoside (1), eriodictyol 7-O-[6″-(3‴-hydroxy-4‴-methoxy cinnamoyl)]-β-D-glucopyranoside (2), and luteolin 7-O-[6″-(3‴-hydroxy-4‴-methoxy cinnamoyl)]-β-D-glucopyranoside (3), and eight known flavonoids were isolated from the whole plants of Elsholtzia bodinieri. The structures of the 3 new compounds were elucidated on the basis of extensive spectroscopic analysis.

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The key intermediate, diethyl 2-acetylamino-2-(2-(4-octanoylphenyl)ethyl)propane-1,3-dioate (13), for the immunomodulatory agent FTY720 (2: fingolimod) was synthesized via Michael addition of diethyl(acetylamino)malonate (6) to 4-octanoylstyrene (12).

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Effects of inorganic salts on disintegration of hydroxypropylmethylcellulose (HPMC) matrix tablets have been studied. Adding disintegrants, such as Ac-di-sol^®, Primojel^®, Kolidon-CL^®, or low substituted hydroxypropylcellulose (L-HPC^®) to HPMC matrix tablets had no effect on disintegration property. Disintegration time was improved by adding NaHCO₃, KH₂PO₄, K₂SO₄, KCl, or NaCl to the HPMC tablets as tablet components. On the other hand, addition of Na₂CO₃, or Na₂SO₄ to the tablets showed no improvement of disintegration. The heat of dissolution of inorganic salts that improved disintegration of tablets was endothermic, while that of inorganic salts that did not improve disintegration of tablets was exothermic. These results suggested that the thermal environment and ionic strength inside the tablet might affect the disintegration of HPMC matrix tablets.

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The solubility of paracetamol in water–ethanol–propylene glycol binary and ternary mixtures at 25 and 30 °C was determined using flask shake method. The generated data extended the solubility database for further computational investigations and also was used to assess the prediction capability of the Jouyban–Acree model. A new version of the model was proposed for modeling the solubility data in water–cosolvent mixtures with the cosolvent concentration of <50% which is required in pharmaceutical formulations. The accuracy of the predicted solubilities was evaluated by the mean percentage deviation (MPD) between the predicted and experimental solubilities. The overall MPD of the Jouyban–Acree model and the log-linear model of Yalkowsky for the entire composition range of the cosolvents were 11.0±8.7 and 55.4±17.8%, respectively; the corresponding values for the predicted solubilities in mixtures having a cosolvent concentration of <50% were 12.0±9.1 and 22.0±11.0%.

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One-pot synthesis of various 2,3-polymethylene-4(3H)-quinazolinones from anthranilic acid, corresponding lactam and SOCl₂ is described, which can be applicable to the synthesis of simple 4(3H)-quinazolinone-derived alkaloids, such as luotonin A, tryptanthrin, and rutaecarpine.

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Three new glycosides, 7-deoxyloganic acid β-D-glucopyranosyl ester (1), (3R)-hydrangenol 8,4′-di-O-β-D-glucopyranoside (2), and (6R,7E,9R)-megastigma-4,7-dien-3-one 9,13-di-O-β-D-glucopyranoside (3), have been isolated from the leaves of Hydrangea macrophylla subsp. serrata (THUNB.) MAKINO (Saxifragaceae). The structures of 1—3 were elucidated on the basis of spectral data and chemical evidence.

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A new monoterpene, sachalol, and three new monoterpene glycosides, sachalosides VI, VII, VIII, were isolated from Rhodiolae Radix, the roots of Rhodiola sachalinensis. The absolute stereostructures of new monoterpenes were elucidated on the basis of chemical and physicochemical evidence including the application of the modified Mosher's method.

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