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[en] Hibiscus rosa-sinensis or commonly known as 'Hibiscus' is a kind of decorative flowers which often grown in a subtropical countries. This plant is often used in the preparation of traditional medicine because of its pharmacological properties that are capable of treating number of health problems. The plant contains several essential bio-active substances and nutrients especially in its flowers and leaves. One of the bioactive substances is β-sitosterol which is abundant in the leaf crude extract. Hibiscus leaves water extract yielded mucilage which is widely used in lowering high body temperature due to fever (antipyretic). Therefore, the main objective of this paper was to determine the maximum concentration of mucilage and time of exhaustive extraction from fresh and dried leaves using a Peleq's mathematical model. Moreover, several analyses were conducted such as qualitative analysis to determine the presence of bioactive substances using high performance liquid chromatography (HPLC) and determination of functional groups by means of fourier transform infrared method (FTIR). Physical properties of the extracts were evaluated to determine its acidity and viscosity of the mucilage with respect to different shear stress. The result show that the extract of dried Hibiscus leaves exhibited high in its concentrations even though the achieved exhaustive extraction was relatively slow as compared to fresh leaves (p < 0.05). Based on the HPLC analysis, the main bio-active substances of β-sitosterol was only existed in fresh leaves samples. The absence of β-sitosterol in dried leaves extract was caused by the loss of other important bio-active substances which possess surfactant capability, due to thermal degradation of drying process or the component itself was deteriorated during the pre-preparation drying process. Furthermore, the FTIR analysis shows that the same composition of the absorption peaks for both extracts with the highest absorption of O-H bonds was observed. This proves that the content of β-sitosterol in both extracts was too small and the composition of other phytosterols was observed to dominate and influence the availability of β-sitosterol in the crude extract. Meanwhile, physical properties analysis of the both extracts was carried to show the effect of drying process on the observed bio-active components. The high acidity of the fresh leaf extract was attributed to the presence of all bio-active ingredients. Meanwhile for the dried leaf extract, a close neutral pH value was observed due to the bio-active decomposition which is acidic in nature and sensitive to heat. (author)
[en] Multi-wavelength fingerprints of Cassia seed, a traditional Chinese medicine (TCM), were collected by high-performance liquid chromatography (HPLC) at two wavelengths with the use of diode array detection. The two data sets of chromatograms were combined by the data fusion-based method. This data set of fingerprints was compared separately with the two data sets collected at each of the two wavelengths. It was demonstrated with the use of principal component analysis (PCA), that multi-wavelength fingerprints provided a much improved representation of the differences in the samples. Thereafter, the multi-wavelength fingerprint data set was submitted for classification to a suite of chemometrics methods viz. fuzzy clustering (FC), SIMCA and the rank ordering MCDM PROMETHEE and GAIA. Each method highlighted different properties of the data matrix according to the fingerprints from different types of Cassia seeds. In general, the PROMETHEE and GAIA MCDM methods provided the most comprehensive information for matching and discrimination of the fingerprints, and appeared to be best suited for quality assurance purposes for these and similar types of sample.
[en] In order to investigate potential therapeutically agents, novel products of Biginelli reaction (4a-l) were synthesized and exposed to cytotoxic and caspase activities, angiogenesis, cell cycle distribution, gene and microRNA expression levels, lipophilicity assessment and docking study. Among the twelve novel compounds (4a-l) evaluated for the cytotoxic activity, five of them (4c, 4d, 4f, 4k and 4l) that showed excellent activity on the tested cell lines (HeLa, LS174 and A549) were selected for further evaluation. Interestingly, compound 4f has up to three times higher selectivity index (SI) towards cancer cells than cisplatin (on HeLa, LS174 and A549 SI = 18.2, 13.5 and 11.2, respectively). The obtained results from cell cycle distribution and caspase activity indicate that tested compounds (4c, 4d, 4f, 4k and 4l) promoted caspase-9 activation, implicated in the intrinsic pathway of apoptosis. Lipophilicity of 4a-l was determinate by using reversed-phase high-performance liquid chromatography. © 2019 Elsevier Inc.
[en] A valid method was developed to assess 2 mg Clonazepam tablets disolution without lactose by high-performance liquid chromatography by UV detection to 254 nm. Establishment of Clonazepam in dissolution medium was confirmed, and parameters of specificity, linearity, and accuracy were assessed, as well as influence of filtration and stability or active principle. Linearity curve was drawed in rank of 1, 2-2,6 μg/mL, with a correlation coefficient similar to 0,99418; statistical test wasn't statistically significant for interceptor and slope. In study, it was possible to demonstrate that stability or active principle in dissolution was maintained in more than double of duration of dissolution assay. (Author)
[en] The application of multi-analyte methods for pesticides carrying chromophoric structures by HPLC is described. Details are given on the materials and methods used. Recorded UV spectra of active substances are presented for allowing the verification of purity and the confirmation of substances eluting from the HPLC column. (author)
[en] Bio-pesticides are becoming increasingly important as pest management tools in various cropping systems in the tropics essentially to remedy problems associated with the indiscriminate use of hard and non-environmental friendly inorganic pesticide. In these past few decades, many bio-pesticidal products, both microbial-based (bacteria, fungi, microsprodia, entomopathogenic nematodes and viruses) and plant-based botanicals (rotenone and azadiracthin) have been studied for their use against insect pests in the tropics. In this study, the effects of the concentration process with respect to the yield of rotenone (mg) and its concentration (mg/mL) are presented extensively. The raw plants were collected from Kota Johor Lama, Johor and sorted to obtain the roots and stems. Only the roots and stems were utilized as raw materials of the extraction process. The rotenone from roots and stems was extracted using the normal soaking extraction (NSE) at 28 to 30 degree Celsius with 95 % (v/v) of acetone as a solvent and the solvent-to-solid ratio of 10 mL/ g. The extraction was carried out for 24 h. Next, the liquid crude extract was concentrated using the rotary evaporator at 50 degree Celsius and 80 mbar of vacuum pressure to remove approximately 90 % of solvent. The fractions of the liquid crude extract were collected (15 min/ mL/ fraction), diluted (1/100 with acetone) and cleaned up (to remove any fine debris) prior to determination of rotenone content (mg) and concentration (mg/mL) by using the reverse-phase high performance liquid chromatography (RP-HPLC). Finally, the results showed that there was a significant effect of thermal degradation or dissipation of rotenone content at higher operating temperature (greater than 40 degree Celsius) with a rapid rotenone reduction for the first 15 min of exposure. The possibilities for better exploitation and identification of the effective operating parameters based on the above mentioned results will be perhaps discussed in the future. (author)
[en] Complete text of publication follows. Nowadays, air conditioners form part of our everyday life because of the climate change. Thus, in the households, hotels, industrial buildings, offices, educational institutions appliances capable of air cooling are installed in an increasing number. Concomitantly, there is a need for the proper operation and maintenance of these air conditioners. In some of these facilities, the air conditioning systems are not cleaned at all due to the high cost of this procedure, therefore employees are exposed to health risks attributed to the precipitation of moisture in the equipment. This condensed vapour phase on the inside wall of the equipment, is a good culture media for the spore of fungi. This concern raised in the eighties of the last century in the USA when several inexplicable newborn infant deceases were registered. The forensic examination revealed that a fungi spore in the lungs of the victims. In the stagnant liquid phase of the filters, the fungi spores are dissolved and reproduced. The proliferated fungi, i.e. Aspergillus species, spread their spores causing adverse health effects like irritation and allergies. The goal of the present work was the identification and quantitative determination of the fungi species and their metabolites in different air conditioners. The investigation revealed the presence of fungi producing mycotoxins. The metabolites were determined by high performance liquid chromatography mass spectrometry hyphenated technique. Fungi species used in this investigation were grown on biologically soil substrata.
[en] A simple, rapid and sensitive RP-HPLC-UV method was developed for quantification of paclitaxel (PTX) and etoposide (ETO) in biological and pharmaceutical samples. Optimization of experimental conditions were performed and standard guidelines were used for the validation of the method. Analytes were separated on Pruospher® Star RP- 18e (250mm × 4.6mm, 5µm) column using ACN and TFA (0.025%) as mobile phase in the ratio of (60:40V/V) with a flow rate of 1 mL/min and detector set at 235 nm. Protein precipitation method was applied for the extraction of analytes from biological samples. The method was applied to in-vitro and in-vivo evaluation of polymeric nanoparticles of etoposide. Solvent evaporation technique was used for the preparation of polymeric nanoparticles (NPs) using polymer PLGA (75:25) and poloxamer as surfactant. The linearity of the method is in the range of 14-500 ng / mL for paclitaxel and 12-1000 ng/mL for etoposide. The LLOD were 5 and 6 ng/mL while the LLOQ were 12 and 14 ng/mL for etoposide and paclitaxel, respectively. The developed method was precise and its intra and inter day co-efficient of variance was below 1%. The method was used for in-vitro and in-vivo evaluation of PLGA polymeric nanoparticles of etoposide. In-vitro evaluation included determination of drug content and drug release while in-vivo evaluation consisted of pharmacokinetic evaluation. (author)
[en] Laboratory data obtained on two different HPLC separation columns and detection by UV and DAD under repeatability conditions are presented and discussed. The behaviour of pesticides on different HPLC columns under gradient and isocratic conditions is evaluated concerning the applicability of respective methodologies. Representative chromatograms of real formulations and “empty” formlants are given for illustration. (author)