Chiral HPLC Separation and Modeling of Four Stereomers of DL-Leucine-DL-Tryptophan Dipeptide on Amylose Chiral Column.

Chiral high-performance liquid chromatography (HPLC) separation and modeling of four stereomers of DL-leucine-tryptophan DL-dipeptide on AmyCoat-RP column are described. The mobile phase applied was ammonium acetate (10 mM)-methanol-acetonitrile (50:5:45, v/v). The flow rate of the mobile phases was 0.8 mL/min with UV detection at 230 nm. The values of retention factors for LL-, DD-, DL-, and LD- stereomers were 2.25, 3.60, 5.00, and 6.50, respectively. The values of separation and resolution factors were 1.60, 1.39, and 1.30 and 7.76, 8.05, and 7.19. The limits of detection and quantitation were ranging from 1.0-2.3 and 5.6-14.0 µg/mL. The simulation studies established the elution orders and the mechanism of chiral recognition. It was seen that π-π connections and hydrogen bondings were the main forces for enantiomeric resolution. The reported chiral HPLC method may be applied for the enantiomeric separation of DL-leucine-DL-tryptophan in unknown matrices. Chirality 28:642-648, 2016. © 2016 Wiley Periodicals, Inc.

Exploring the antifilarial potential of an important medicinal plant Typhonium trilobatum (L. Schoot): Isolation, characterization, and structural elucidation of bioactive compounds against Brugia malayi.

ETHNOPHARMACOLOGY RELEVANCE: The plant Typhonium trilobatum has been utilized in traditional medicine for the treatment of many ailments, including parasitic infections. Recent examinations indicate that the bioactive substances from this plant may have antiparasitic activities against Brugia malayi, which have not been determined. PURPOSE: The parasitic nematodes Brugia malayi, Brugia timori, and Wuchereria bancrofti causing lymphatic filariasis, remain a significant challenge to global public health. Given the ongoing nature of this enduring menace, the current research endeavours to examine the efficacy of an important medicinal plant, Typhonium trilobatum. METHODS: Different extracts of the T. trilobatum tubers were evaluated for their antiparasitic activity. The most prominent extract was subjected to Gas Chromatography Mass Spectrometry (GC-MS) and High Performance Liquid Chromatography (HPLC) followed by Column Chromatography for isolating bioactive molecules. The major compounds were isolated and characterized based on different spectroscopic techniques (FTIR, NMR and HRMS). Further, the antiparasitic activity of the isolated compounds was evaluated against B. malayi and compared with clinically used antifilarial drugs like Diethylcarbamazine and Ivermectin. RESULTS: The methanolic extract of the tuber exhibited significant antiparasitic activity compared to the other extracts. The bioactive molecules isolated from the crude extract were identified as Linoleic acid and Palmitic acid. Antiparasitic activity of both the compounds has been performed against B. malayi and compared with clinically used antifilarial drugs, Ivermectin and DEC. The IC50 value of Linoleic acid was found to be 6.09 ± 0.78 µg/ml after 24 h and 4.27 ± 0.63 µg/ml after 48 h, whereas for Palmitic acid the value was 12.35 ± 1.09 µg/ml after 24 h and 8.79 ± 0.94 µg/ml after 48 h. The IC50 values of both the molecules were found to be similar to the standard drug Ivermectin (IC50 value of 11.88 ± 1.07 µg/ml in 24 h and 2.74 ± 0.43 µg/ml in 48 h), and much better compared to the DEC (IC50 values of 194.2 ± 2.28 µg/ml in 24 h and 101.8 ± 2.06 µg/ml in 48 h). Furthermore, it has been observed that both the crude extracts and the isolated compounds do not exhibit any detrimental effects on the J774.A.1 macrophage cell line. CONCLUSION: The isolation and characterization of bioactive compounds present in the methanolic tuber extract of Typhonium trilobatum were explored. Moreover, the antimicrofilarial activity of the crude extracts and its two major compounds were determined using Brugia malayi microfilarial parasites without any significant side effects.

The impact of COVID-19 lockdown on the clinical and radiological outcomes of both-bone forearm fractures treated by compression plating at a tertiary care centre in India: a retrospective study.

BACKGROUND: The COVID-19 pandemic has affected everyone's life. In India, the nationwide lockdown was enforced from March 25, 2020. It has significantly affected the healthcare delivery system. Both-bone forearm (BBFA) fractures are commonly encountered as an emergency. Surgical management with plate fixation is often the primary mode of management in adults and adolescents. During the first wave of the COVID-19 pandemic, follow-up of patients with BBFA fractures who had undergone surgery before the lockdown was severely affected. To understand the effect of lack of regular follow-up on the outcome of BBFA fracture patients, in this study, we assessed their radiological, functional, and clinical outcomes at least 12 months after surgery. This study examined if a lack of routine follow-ups in surgically treated BBFA fracture patients has any impact on their short-term outcomes. METHODS: We included 30 patients with BBFA fractures who were operated prior to the COVID-19 lockdown and assessed their radiological, functional, and clinical outcomes 12 months after surgery. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, Patient-Rated Wrist Evaluation (PRWE) score, Grace and Eversmann's score, and Mayo Elbow Performance Index (MEPI) score were assessed subjectively. Fracture site tenderness, and wrist, forearm, elbow, and grip strength range of motion (ROM) were objectively evaluated. Radiological union was recorded using standard forearm anteroposterior and lateral radiography. RESULTS: At follow-up, 28 patients had union at the fracture site, and two patients had a nonunion. A significant reduction was observed in the mean ROM of the injured forearm compared with the uninjured forearm in supination (17.76% less), pronation (31.4% less), dorsiflexion (32% less), palmar-flexion (24.6% less), elbow flexion-extension arc (2.5% less), and grip strength (18% less). The percentage reduction in pronation and dorsiflexion was higher than that in supination and palmar-flexion, respectively. Grace and Eversmann's score was excellent in 16 patients, good in 4, acceptable in 7, and poor in 3 patients. The mean QuickDASH score was 6 ± 6.6. The mean PRWE and MEPI scores were 7 ± 4.5 and 87.16, respectively. The MEPI score was excellent in 21 patients, good in 6, fair in 2, and poor in 1 patient. CONCLUSION: The clinical, functional, and radiological outcomes of adult patients with BBFA fractures who were treated with compression plating were satisfactory. Inadequate follow-up during the COVID-19 first wave in India had minimal to no effect on their short-term outcomes.

A Rapid and Validated RP-HPLC Method for the Simultaneous Quantification of Benzoic Acid, Metronidazole and Miconazole Nitrate in Vaginal Formulations.

A rapid, specific, precise and accurate reversed-phase high-performance liquid chromatography method has been developed and validated for the determination of benzoic acid, metronidazole and miconazole nitrate in vaginal formulations of cream and tablet (excluding benzoic acid). The validation was carried out with reference to ICH guidelines. The chromatography was carried out on a Zorbax SB-CN column (250 × 4.6 mm, 5 µm) linear gradient elution with mixture of solvent A (phosphate buffer) and solvent B (acetonitrile) as a mobile phase at the flow rate of 1.0 mL/min and dual mode of detection that is 233 nm for benzoic acid and miconazole nitrate and 319 nm for metronidazole. The limit of detection and limit of quantification are 1.07, 0.79 and 0.62 µg/mL and 3.23, 2.40 and 1.88 µg/mL for benzoic acid, metronidazole and miconazole nitrate, respectively. The linearity of benzoic acid, metronidazole and miconazole nitrate showed a correlation coefficient of 0.9997, 0.9995 and 0.9993, respectively. The good results were achieved with respect to repeatability of relative standard deviation ≤2% and recovery within 98.0-102.0%. The selected column in this study performed well. The method is simple, accurate and precise, and may be recommended for routine quality control test for any dosage forms containing benzoic acid, metronidazole and miconazole nitrate.

Validated chiral high performance liquid chromatography separation method and simulation studies of dipeptides on amylose chiral column.

Chiral resolution of dl-alanine-dl-tyrosine and dl-leucine-dl-phenylalanine dipeptides was achieved on AmyCoat-RP column. The mobile phase used for dl-alanine-dl-tyrosine was acetonitrile-ammonium acetate (10mM, pH 6.0) [50:50, v/v]. It was acetonitrile-methanol-ammonium acetate (10mM; pH adjusted to 4.5 with glacial acetic acid) [50:20:30, v/v] for dl-leucine-dl-phenylalanine. The flow rate of the mobile phases was 0.8mL/min with UV detection at 275nm. The values of retention factors for ll-, dd-, dl- and ld-stereomers of dl-alanine-dl-tyrosine were 1.71, 2.86, 5.43 and 9.42, respectively. The values of separation and resolution factors were 1.67, 1.90 and 1.73 and 2.88, 6.43 and 7.90, respectively. Similarly, these values for dl-leucine-dl-phenylalanine stereomers were 1.50, 2.88, 3.50 and 4.07 (retention factors), 1.92, 1.22 and 1.62 (separation factors) and 2.67, 1.55 and 2.30 (resolution factors). The limits of detections and quantitation were ranged from 2.03 to 6.40 and 6.79 to 21.30µg/mL, respectively. The modeling studies were in agreement with the elution orders. The mechanism of chiral recognition was established by modeling and chromatographic studies. It was observed that hydrogen bondings and π-π interactions are the major forces for chiral separation.