Isomerization and Stabilization of Amygdalin from Peach Kernels

In this study, isomerization conditions, cytotoxic activity, and stabilization of amygdalin from peach kernels were analyzed. Temperatures greater than 40 °C and pHs above 9.0 resulted in a quickly increasing isomer ratio (L-amygdalin/D-amygdalin). At acidic pHs, isomerization was significantly inhibited, even at high temperature. Ethanol inhibited isomerization; the isomer rate decreased with the ethanol concentration increasing. The growth-inhibitory effect on HepG2 cells of D-amygdalin was diminished as the isomer ratio increased, indicating that isomerization reduces the pharmacological activity of D-amygdalin. Extracting amygdalin from peach kernels by ultrasonic power at 432 W and 40 °C in 80% ethanol resulted in a 1.76% yield of amygdalin with a 0.04 isomer ratio. Hydrogel beads prepared by 2% sodium alginate successfully encapsulated the amygdalin, and its encapsulation efficiency and drug loading rate reached 85.93% and 19.21%, respectively. The thermal stability of amygdalin encapsulated in hydrogel beads was significantly improved and reached a slow-release effect in in vitro digestion. This study provides guidance for the processing and storage of amygdalin.

Solvent- and catalyst-free transamidations of unprotected glycosyl carboxamides

New green and atom efficient transamidation reactions of various glycosyl carboxamides with primary and secondary amines are described.

Concurrent quantification and comparative pharmacokinetic analysis of bioactive compounds in the Herba Ephedrae-Semen Armeniacae Amarum herb pair

The Mahuang-Xingren herb-pair (MX), the combination of Herba Ephedrae (Mahuang in Chinese) and Semen Armeniacae Amarum (Xingren in Chinese), is a classical combination used in traditional Chinese Medicine to treat asthma and bronchitis. A simple and reliable ultra-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously quantify and compare the pharmacokinetics of 5 ephedra alkaloids and epimers of amygdalin and prunasin in rat plasma after oral administration of Mahuang, Xingren, and MX aqueous extracts. Samples were pretreated by a single-step protein precipitation with acetonitrile, and diphenhydramine hydrochloride and puerarin were used as internal standards. Pharmacokinetic parameters were investigated using DAS 3.2.2 (Mathematical Pharmacology Professional Committee of China, Shanghai, China). The validated method demonstrated adequate sensitivity, selectivity, and process efficiency for the bioanalysis of 8 compounds, including 3 pairs of epimers. MX administration improved the bioavailability of amygdalin and prunasin. Furthermore, MX facilitated intake of lower doses of ephedra alkaloids and increased elimination rates in comparison with Mahuang alone. These results illustrate the rationale behind the preferred use of the combination of Mahuang and Xingren. To our knowledge, this is the first report of stereo-selective metabolism of amygdalin. Further, the metabolic mechanism underlying this phenomenon merits future research attention.

Amygdalin isolated from Semen Persicae (Tao Ren) extracts induces the expression of follistatin in HepG2 and C2C12 cell lines

BACKGROUND

The Chinese medicine formulation ISF-1 (also known as Bu-Yang-Huan-Wu-Tang) for post-stroke rehabilitation could increase the expression of growth-regulating protein follistatin by approximately 4-fold. This study aims to identify the active compounds of ISF-1 for the induction of follistatin expression.

METHODS

Active compounds in ISF-1 responsible for induction of follistatin were identified by a bioactivity-guided fractionation procedure involving liquid-liquid extraction, HPLC separation and RT-PCR detection. The aqueous extracts of seven ISF-1 ingredients including Semen Persicae (Tao Ren) and the S. Persicae-derived fractions were assayed for the induction of follistatin mRNA expression in human hepatocarcinoma HepG2 cells by RT-PCR. The concentrations of isolated compounds were proportionally normalized to the reported IC50 concentration (5.8 mg/mL) of the formulation ISF-1 in HepG2. The active fractions were characterized by reverse-phase HPLC on a C18 column and identified by mass spectrometry.

RESULTS

Three ingredients of ISF-1, namely S. Persicae (Tao Ren), Pheretima (Di Long), and Flos Carthami (Hong Hua), induced the expression of follistatin mRNA. Among these, the ingredient S. Persicae were the most active, and amygdalin from S. Persicae extract was identified as a novel follistatin inducer. Amygdalin stimulated the growth of skeletal muscle cell line C2C12 cells in a concentration-dependent manner.

CONCLUSIONS

Amygdalin isolated from S. Persicae extract in ISF-1 through a bioactivity-guided fractionation procedure induced the expression of follistatin in HepG2 and C2C12 cell lines.

A review of developments in the methodology and application of microemulsion electrokinetic chromatography

MEEKC is a mode of CE, which utilizes microemulsion (ME) as the BGE to achieve separation of a diverse range of analytes. MEs are composed of nanometer-sized oil droplets suspended in aqueous buffer which are stabilized by the presence of a surfactant and co-surfactant. These MEs are commonly referred to as oil-in-water MEs and their application in MEEKC has been extensively examined. This review details advances in the theory, methodology, and application of MEEKC during the period 2010-2012. Areas covered include online sample concentration, advances in chiral separations, use of coated capillaries, chemometric approaches, and the use of novel additives to the ME system. This review also provides the reader with an introduction to MEEKC and a presentation of recent applications.