SEPARATION OF THREE TRITERPENE ACIDS IN LEAVES OF DIOSPYROS KAKI BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY USING HYDROXYPROPYL-β-CYCLODEXTRIN AS MOBILE PHASE MODIFIER

A Review: Pharmacological Effect of Natural Compounds in Diospyros kaki Leaves from the Perspective of Oxidative Stress

Oxidative stress is caused by an imbalance between reactive oxygen species and antioxidant levels. Current research suggests that oxidative stress is one of the key factors in the development of many chronic diseases, and it has been a concern for many years. Many natural compounds have been studied for their special free-radical-scavenging properties. The major chemical constituents of the leaves of Diospyros kaki are flavonoids and triterpenoids, both of which are potential antioxidants that can prevent damage caused by reactive oxygen species or reactive nitrogen species and ameliorate diseases associated with oxidative stress. In addition to the major constituents such as flavonoids and triterpenoids, the leaves of Diospyros kaki include compounds such as phenylpropanoids, alkaloids, phenolic acids, and terpenes. Studies have shown these compounds have certain antioxidant and neuroprotective activities. Experiments have shown that flavonoids or the extracts from the leaves of Diospyros kaki have a variety of good pharmacological activities, which could activate oxidative stress and mitochondrial apoptosis, inhibit the proliferation of human prostate cancer cells and induce apoptosis. It also could achieve the effect of anti-cancer cell proliferation and induce apoptosis by regulating oxidative stress. The main chemical substance of the leaves of Diospyros kaki regulating oxidative stress may be these multi-hydroxyl structure compounds. These natural products exhibit significant antioxidant activity and are an important basis for the leaves of Diospyros kaki to treat human diseases by regulating oxidative stress. This review summarizes the structural types of natural products in the leaves of Diospyros kaki and elaborates the mechanism of the leaves of Diospyros kaki in neuroprotection, anti-diabetes, renal protection, retinal degenerative diseases, and anti-cancer from a new perspective of oxidative stress, including how it supplements other pharmacological effects. The chemical constituents and pharmacological effects of the leaves of Diospyros kaki are summarized in this paper. The relationship between the chemical components in the leaves of Diospyros kaki and their pharmacological effects is summarized from the perspective of oxidative stress. This review provides a reference for the study of natural anti-oxidative stress drugs.

Enantioseparation of Five Racemic N-alkyl Drugs by Reverse Phase HPLC Using Sulfobutylether-β-cyclodextrin as Chiral Mobile Phase Additive

Analytical enantioseparations of five N-alkyl drugs, fluoxetine hydrochloride, labetalol, venlafaxine hydrochloride, trans-paroxol and atropine sulfate, were investigated by RP-HPLC with sulfobutylether-β-cyclodextrin as chiral mobile phase additive. Effects of various factors such as composition of mobile phase, concentration of cyclodextrins and column temperature on retention and enantioselectivity were studied. Apparent formation constant between methanol, acetonitrile and sulfobutylether-β-cyclodextrin were determined to be 2.90 × 10^-3 and 1.00 × 10^-4 L mmol^-1 under 25 °C using UV-spectrophotometry. Van't Hoff plots were used to investigate thermodynamic parameters for enantiomers-stationary phase interaction and formation of inclusion complex. Two retention models were employed individually for evaluation of inclusion complexation between five racemates and sulfobutylether-β-cyclodextrin. The second model with complex adsorption was more accord with the retention behavior of fluoxetine hydrochloride, labetalol and venlafaxine hydrochloride enantiomers, while the first model was more consistent with the retention behaviors of trans-paroxol and atropine sulfate. In the selected mobile phase, stoichiometric ratio for both of inclusion complex was found to be 1:1. This article is protected by copyright. All rights reserved.

Liquid chromatographic study of two structural isomeric pentacyclic triterpenes on reversed-phase stationary phase with hydroxypropyl-β-cyclodextrin as mobile phase additive

Retention behavior of two structural isomeric pentacyclic triterpenic acids, maslinic acid and corosolic acid, was investigated by reverse phase high performance liquid chromatography (HPLC) with hydroxypropyl-β-cyclodextrin (HP-β-CD) as mobile phase additive. Inclusion complexation of maslinic acid, corosolic acid with hydroxypropyl-β-cyclodextrin was evaluated under different concentration of hydroxypropyl-β-cyclodextrin. Apparent formation constant (K_m) between methanol and hydroxypropyl-β-cyclodextrin was determined to be 13.82 L mol^-1 under 25 °C using UV-spectrophotometry. Two retention models were employed individually for evaluation of inclusion complexation between the two pentacyclic triterpenic acids and hydroxypropyl-β-cyclodextrin. It was found that a higher apparent formation constant (K_f) for corosolic acid and hydroxypropyl-β-cyclodextrin was obtained, 19115 L mol^-1, indicating that a greater affinity of hydroxypropyl-β-cyclodextrin with corosolic acid was produced compared with that of maslinic acid, 11775 L mol^-1, in the selected mobile phase, and stoichiometric ratio for both of inclusion complex was found to be 1:1. Thermodynamic analysis showed that a negative standard enthalpy change (ΔH) and an entropy change (ΔS*) for analyte transfer were obtained, where ΔH of maslinic acid and corosolic acid was found to be -10.188 kJ mol^-1 and -10.650 kJ mol^-1, ΔS* of two compounds was -2.092 and -2.180, respectively, indicating that transfer of structural isomers from mobile phase to stationary phase was enthalpically driven. Meanwhile, positive values were obtained for standard enthalpy change and standard entropy change, 136 kJ mol^-1 and 274 kJ mol^-1 and 536 J mol^-1 K^-1and 1004 J mol^-1 K^-1, for inclusion complexation between maslinic acid, corosolic acid and hydroxypropyl-β-cyclodextrin, while negative values were obtained for Gibbs free energy during formation of inclusion complex, -160 kJ mol^-1 and -299 kJ mol^-1, indicating a spontaneous inclusion reaction happened.

α-Glucosidase enzyme inhibitory effects and ursolic and oleanolic acid contents of fourteen Anatolian Salvia species

During the last decade, ursolic and oleanolic acids have been of considerable interest because of their α-glucosidase inhibitory activities and potential effects for treatment of type 2 diabetes. A simple and sensitive reversed-phase HPLC method was developed for the simultaneous determination of ursolic acid and oleanolic acid. The optimal mobile phase was selected as 85% acetonitrile solution. The limit of detection of the method for ursolic acid and oleanolic acid were 14 ng mL-1 and 13 ng mL-1, respectively. The method showed good precision and accuracy with intra-day and inter-day variations of 0.54% and 7.33% for ursolic acid, intra-day and inter-day variations of 0.51% and 5.26% for oleanolic acid, and overall recoveries of 97.8% and 98.5% for ursolic acid and oleanolic acid, respectively. Application of the method to determine the ursolic acid and oleanolic acid contents in the Salvia species revealed both compounds, with varying amounts between 0.21-9.76 mg g-1 ursolic acid and 0.20-12.7 mg g-1 oleanolic acid, respectively, among 14 Salvia species analyzed. Additionally, the plant extracts were analyzed for their inhibitory activities on α-glucosidase. According to the results of this assay, the extracts showed considerable activity on α-glucosidase with IC50 values from 17.6 to 173 μg mL-1. A strong negative correlation was detected between the amounts of both acids and IC50 values of extracts. Anatolian Salvia species have great potential as functional plants in the management of diabetes.

Persimmon (Diospyros kaki L.) leaves: a review on traditional uses, phytochemistry and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Persimmon (Diospyros kaki L.) leaves, known as Shi Ye (in Chinese), have a long history as a Chinese traditional medicine for the treatment of ischemia stroke, angina, internal hemorrhage, hypertension, atherosclerosis and some infectious diseases, etc. Additionally, persimmon leaves could be used as healthy products, cosmetics and so on, which have become increasingly popular in Asia, such as Japan, Korea and China etc.

AIM OF THE REVIEW

The present paper reviewed the ethnopharmacology, phytochemistry, analytical methods, biological activities and toxicology of persimmon leaves in order to assess the ethnopharmacological use and to explore therapeutic potentials and future opportunities for research.

MATERIALS AND METHODS

Information on persimmon leaves were gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Pudmed, Web of Science, CNKI and EMBASE) and libraries. Additionally, information was also obtained from some local books.

RESULTS

Persimmon leaves have played an important role in Chinese system of medicines. The main compositions of persimmon leaves were flavonoids, terpenoids, etc. Scientific studies on extracts and formulations revealed a wide range of pharmacological activities, such as, antioxidative, hypolipidemic, antidiabetic, antibacterial, hemostasis activities and effects on cardiovascular system. Based on the pharmacological activities, persimmon leaves were widely used in clinic including treatment of cardiovascular disease, hemostasis, antibacterial, anti-inflammatory and beauty treatment.

CONCLUSIONS

Persimmon leaves probably have therapeutic potential in the prevention and treatment for cerebral arteriosclerosis, diabetes, hypertension. It showed significant neuroprotection against ischemia/reperfusion injury in vivo and in vitro. Moreover, it can regulate immune function and inhibite inflammation. Further investigations are needed to explore individual bioactive compounds responsible for these pharmacological effects in vitro and in vivo and the mode of actions. Further safety assessments and clinical trials should be performed before it can be integrated into medicinal practices.