Analysis of phenolic profile, total phenolic content and antioxidant activity in Anacardium occidentale leaves

Anacardium occidentale young leaves are consumed traditionally as part of a Southeast Asian diet. The regular consumption is believed to have beneficial effects on health in general and potentially against type 2 Diabetes mellitus due to its high content of polyphenols. This study was aimed to investigate the polyphenol content of the plant using two methanol extracts; Free Phenolic Extract (FPE) and Bound Phenolic Extract (BPE) as well as highlight the presence of six phenolic acids and flavonoids namely; gallic acid, sinapinic acid, caffeic acid, ferulic acid, quercetin and kaempferol using High performance liquid chromatography-photodiode array (HPLC-UV-Vis). The results for polyphenols and flavonoids content showed high amounts of total polyphenols in BPE with 8.5±0.57 mg GAE/g as well as high amounts of total flavonoids in both extracts FPE and BPE with 0.58±0.06 and 0.86±0.05 mg QE/g respectively (p<0.05). The presence of these polyphenols was further confirmed by measuring the antioxidant activity through the scavenging of the free radical DPPH which showed an IC50 value for FPE (5.17±0.64 µg/ mL, BPE (4.96±0.12 µg/mL) compared to the positive control ascorbic acid (4.91±0.43 µg/mL). The high-performance liquid chromatography-photodiode array confirmed the presence of all four targeted phenolic acids with the highest amount showing in gallic acid and sinapinic acid in BPE with 148.12±6.44 µg gallic acid/g dry weight and 47.02±1.94 µg sinapinic acid/g dry weight respectively. As for flavonoids, quercetin was present in both extracts with 20.38±1.22 µg/g dry weight in BPE and 5.21±0.1 µg/g dry weight in FPE while Kaempferol was not detectable in either extract. These findings confirmed the importance of A. occidentale as a rich source of polyphenols which can be further investigated to determine its effects in-vitro and in-vivo on non-communicable diseases such as type 2 diabetes.

STABILITY INDICATING RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF SIMETHICONE, DOMPERIDONE, MAGALDRATE AND SODIUM ALGINATE: APPLICATION TO SYRUP FORMULATION

A rapid and validated stability indicating RP-HPLC method using isocratic elution and coupled with photodiode array detection was developed for quantifying the content of simethicone, domperidone, magaldrate and sodium alginate in bulk and syrup formulation. The best mobile phase used in this study consisted of 0.1 % orthophosphoric acid/acetonitrile (50/50, V/V) with a flow rate of 0.7 mL min-1. Under optimized conditions used in this study, selected drugs were eluted at 3.301 min (simethicone), 4.293 min (domperidone), 5.220 min (magaldrate) and 6.149 min (sodium alginate) within 12 min run time without any interfering excipients. Peak areas and selected drug content demonstrated excellent linearity (simethicone – 5 to 30 µg mL-1; domiperidone – 2.5 to 15 µg mL-1; magaldrate – 120 to 720 µg mL-1; sodium alginate – 25 to 150 µg mL-1). Percent recovery, which represents accuracy, was 99.12–100.18 % for simethicone, 99.59-100.52 % for domperidone, 99.23-100.25 % for magaldrate and 99.57-100.02 % for sodium alginate. Percent relative standard deviation, which represents precision, was observed in the range of 0.078-0.983 % (simethicone), 0.528-0.861 % (domperidone), 0.278-1.069 % (magaldrate), 0.316-0.572 % (sodium alginate). The developed method displayed favourable accuracy and recovery and was suitable for determining the content of simethicone, domperidone, magaldrate and sodium alginate combination in syrup formulations.

Simultaneous Determination of Four Marker Compounds in Lobelia chinensis Lour. Extract by HPLC-PDA

Lobelia chinensis Lour. (L. chinensis) has traditionally been used as a treatment for snake bites, high fever, jaundice, edema, and diarrhea, and modern studies have reported its anti-inflammatory, antioxidant, and antiviral activities. L. chinensis contains various compounds, such as flavonoids and coumarins, and its flavonoid components have been identified in many studies. In this study, a high-performance liquid chromatograph equipped with a photodiode array (PDA) detector and an Aegispak C18-L reverse-phase column (4.6 mm × 250 mm i.d., 5 μm) was used to simultaneously analyze four marker components in L. chinensis for standardization purposes. HPLC-PDA (detection at 340 nm), performed using a 0.1% formic acid-water/0.1% formic acid-acetonitrile gradient, separated the four marker compounds: luteolin-7-O-β-d-glucuronopyranosyl (1→2)-O-β-d-glucuronopyranoside, clerodendrin, chrysoeriol-7-O-diglucuronide, and diosmin. The developed analytical method showed excellent linearity values (r2 > 0.9991), limits of detection (LODs: 0.376–2.152 μg/mL), limits of quantification (LOQs: 1.147–6.521 μg/mL), intra- and inter-day precisions (RSD < 1.96%), and analyte recoveries (96.83–127.07%; RSD < 1.73%); thus, it was found to be suitable for the simultaneous analysis of these four marker compounds in L. chinensis.

Mobility of Organotin Pesticides: Azocyclotin And Cyhexatin In Clayey And Sandy Soils From The Northern Paraná State - Brazil

Azocyclotin and cyhexatin are pesticides commonly used in mite control. However, these organotin compounds are highly harmful to the aquatic ecosystem and supposedly mobile in the soil. In addition to not existing defined rules of use, few studies have been carried out on organotins' behavior and environmental control. Liquid chromatography has been pointed out for the OTC quantitation because of gas chromatography's thermal stability and derivatization limitations. Hence, a new high-performance liquid chromatography method with photodiode array detection (HPLC-PDA) was developed for quality assurance and quality control (QA/QC) and environmental performance assessment purposes. Hysteresis index (\emph{HI}) and mobilization factor were determined from sorption/desorption in sandy and clayey soils to assess mobility and environmental risk. Mobilization was observed for the two compounds by applying the dual-mode Freundlich-Langmuir model to the isotherms. Azocyclotin showed greater mobility, 23\% and 19\%, and \emph{HI} of $-$0.15 and 7.8$\times$10$^{-4}$ for clayey and sandy soil samples, respectively. Although cyhexatin was practically immobile for both soil samples, it can be mobilized as an azocyclotin metabolite, increasing the environmental impact and risk for agricultural uses.

Phytohormones and Elicitors Enhanced the Ecdysteroid and Glycosylflavone Content and Antioxidant Activity of Silene repens

In the course of the ongoing chemical study of species of Silene genus, S. repens Patrin as a common species of the genus, was selected as the object of this study. Using high-performance liquid chromatography with photodiode array detection and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PDA-ESI-tQ-MS), the presence of 12 ecdysteroids and 6 glycosylflavones was established in S. repens introduced seedlings. 20-Hydroxyecdysone and polypodine B, as well as sileneside E and schaftoside, were the dominant compounds in introduced seedlings of S. repens. The effect of exogenous phytohormones and elicitors on the productivity and accumulation of ecdysteroids and glycosylflavones in introduced seedlings of S. repens was investigated for the first time. It was found that the use of ethyl arachidonate (100 mg/L) to increase the productivity of S. repens is justified. To obtain S. repens with a high content of ecdysteroids and glycosylflavones, it is recommended to apply epibrassinolide (100 mg/L) and 4-chlorophenoxyacetic acid (100 mg/L), respectively. Antioxidant activity of S. repens against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·) was determined, and it was revealed that sileneside E and schaftoside, as well as meloside А and isovitexin had the highest antioxidant activity among the studied compounds of S. repens.

The Improved Method for Determination of Orotic Acid in Milk by Ultra-Fast Liquid Chromatography with Optimized Photodiode Array Detection

Ultra-fast liquid chromatography (UFLC) with a photodiode array detector (DAD) for simple and rapid determination of orotic acid (OAc) in milk of sheep and cows is described. Milk samples are treated with acetonitrile (1:1, v/v) and then centrifuged at 4 °C. To 1 mL of the obtained supernatant 9 mL of ultrapure water was added. Subsequently, 0.5–6 µL of the resulting solution was injected into the UFLC-DAD system. Separation and quantification of OAc in milk samples was achieved using two Kinetex C18 columns (1.7 µm, 150 mm × 2.1 mm, i.d., 100 Å; Phenomenex) fitted with a pre-column of 4 mm × 2 mm, i.d. (Phenomenex) containing C18 packing material. All separations were performed at a column temperature of 35 °C while the ambient temperature was 21–24 °C. Satisfactory separation of OAc from endogenous species of milk can be achieved using the binary gradient elution program and UV detection at wavelengths 278 nm. Our original procedure resulted in suitable separation and quantification of OAc in milk samples; OAc eluted at 6.44 ± 0.03 min. The total run time of OAc analysis (including re-equilibration) was 27 min. As expected, the OAc peak was absent from the blank when the proposed gradient elution program and UV detection at 278 nm was used. The average recoveries of OAc standards added to milk samples were satisfactory (96.7–105.3%). The low inter-and intra-assay coefficient of variation derived from the measurements of OAc in cow and ovine milk samples (i.e., 0.784%, 1.283% and 0.710%, 1.221%, respectively) and in O-Ac standards (i.e., 0.377% and 0.294%, respectively), as well as high recoveries of OAc added to ovine and cows’ milk (~100%) and the low detection (0.04 ng) and quantification (0.12 ng) limits point to satisfactory accuracy, precision and sensitivity of the reported method. OAc concentrations in ovine milk samples were within the range from 25 to 36 mg/L, while OAc levels in cows’ milk samples was found in the range of 32–36 mg/L. Our original procedure is suitable for routine quantification of OAc in milk of ewes and cows.

PREPARATION AND STABILITY EVALUATION OF LL-37 CREAM

Objective: The present study aimed to prepare LL-37 in a cream formulation (O/W emulsion) and evaluate its stability by determining the physical changes in the cream and concentration of LL-37 using validated high-performance liquid chromatography. Methods: The method was conducted at room temperature using a C18 column (5 µm × 250 mm × 4.6 mm) as a stationary phase, a mixture of 0.1% trifluoroacetic acid (TFA)/water (A) and 0.1% TFA/acetonitrile (B) (85:15) as the mobile phase, a flow rate of 1.0 mL/min, and photodiode array set at 228 nm as the detector. The method was validated in compliance with the Association of Official Analytical Chemists and International Conference on Harmonization guidelines. It demonstrated excellent linearity, accuracy, precision, specificity, the limit of detection, and limit of quantitation. Results: The chromatographic analysis indicated minimal degradation of LL-37 during the 12-week, with a predicted expiry time of 99 and 75 mo stored at 4 °C and 28 °C, respectively. Conclusion: LL-37 cream establishes good physical characteristics and stabilizes the active ingredient, especially at 4 °C and 28 °C storage. Therefore, the emulsion delivery system of LL-37 cream is harmless and stable as a novel alternative vehicle of LL-37.