Chemical Constituents from Aegle marmelos Fruits

Aegle marmelos (Rutaceae) is a deciduous shrub or tree and typically known as bael throughout Southeast Asia and has been used as a medicinal plant and a food ingredient. In this study eight compounds were determined to be O-(3,3-dimethylallyl) halfordinol (1), (R)-aegeline (2), (R)-marmeline (3), imperatorin (4), xanthotoxol (5), valencic acid (6), vanillic acid (7) and rutin (8). The chemical structures of the isolates were elucidated through spectroscopic evidence including 1D, 2D NMR, ESI-Q-TOF-MS and optical rotation.

A New Coumestan Glucoside from Eclipta prostrata

Eclipta prostrata is an annual herb, belonging to Asteraceae family, and has been traditionally used to improve immunity and treat hepatitis and bacterial disease in Korea. In this study, a new coumestan glucoside (1) along with ten known compounds (2 – 11) was isolated from E. prostrata. The chemical structures of isolates were elucidated to be wedelolactone-9-O-β-D-glucopyranoside (1), wedelolactone (2), demethylwedelolactone (3), apigenin (4), apigenin-7-sulfate (5), luteolin (6), luteolin-7-sulfate (7), luteolin-7-O-β-D-glucopyranoside (8), pratensein-7-O-β-D-glucopyranoside (9), 3,4-di-O-caffeoylquinic acid (10) and 3,5-di-O-caffeoylquinic acid (11) based on the spectroscopic evidence.

Isolation of Phytochemicals from Salvia plebeia Using Countercurrent Chromatography Coupled with Reversed-phase HPLC

Salvia plebeia R. Br. is a plant which has been used as an edible crop and traditional medicine in Asian countries. In this study, HPLC-PDA analysis and countercurrent chromatography (CCC) coupled with reversed-phase (RP) HPLC method were applied to isolate ten isolates from 3.3 g of n-butanol soluble extract from hot-water extract of S. plebeia. The use of CCC enabled us to efficiently fractionate the starting material with less sample loss and facilitate the isolation of compounds from S. plebeia extract using RP-HPLC. The isolates were determined to be caffeic acid (1), 6-hydroxyluteolin 7-O-β-D-glucoside (2), eudebeiolide B (3), (R)-rosmarinic acid (4), homoplantaginin (5), eudebeiolide D (6), plebeiolide C (7), salpleflavone (8), eupafolin (9) and hispidulin (10) based on the spectroscopic evidence.

A New Coumestan Glucoside from Eclipta prostrata

Eclipta prostrata is an annual herb, belonging to Asteraceae family, and has been traditionally used to improve immunity and treat hepatitis and bacterial disease in Korea. In this study, a new coumestan glucoside (1) along with ten known compounds (2 – 11) was isolated from E. prostrata. The chemical structures of isolates were elucidated to be wedelolactone-9-O-β-D-glucopyranoside (1), wedelolactone (2), demethylwedelolactone (3), apigenin (4), apigenin-7-sulfate (5), luteolin (6), luteolin-7-sulfate (7), luteolin-7-O-β-D-glucopyranoside (8), pratensein-7-O-β-D-glucopyranoside (9), 3,4-di-O-caffeoylquinic acid (10) and 3,5-di-O-caffeoylquinic acid (11) based on the spectroscopic evidence.

An Exploration of the Oryza sativa L. Cyanidin-3-glucoside on the Cognitive Function in Older Adults with Subjective Memory Impairment

OBJECTIVE: Cyanidin-3-glucoside (C3G), is a component of anthocyanin, have been considered to positively influence cognition and be beneficial for the prevention and treatment of dementia. We aimed to assess the safety and efficacy of cyanidin-3-glucoside-rich Oryza sativa L. (black rice) extract on cognitive function. METHODS: A 12-weeks double-blind randomized, placebo controlled trial assessed safety and cognitive outcomes in participants with subjective memory impairment (n=48) following consumption of 6 black rice extract capsules or a placebo. Cognitive function was assessed using the ADAS-cog and the CERAD-K. Subjective memory impairment also assessed. Safety was assessed by hematologic blood test, urine analysis, and participant reports of adverse events. RESULTS: There was significant improvement on subjective memory in intervention group. There was no statistically significant difference in objective cognitive outcomes following 12 weeks of consuming black rice extract. ADAS-cog scores, however, trended toward improvement in the intervention group compared to the placebo group. There was no adverse event. CONCLUSION: Although significant improvement in objective cognitive function was not proved, we found that C3G-rich Oryza sativa L. extract improves subjective memory in this study. Therefore the results may be informative of the possible effectiveness of the C3G-rich Oryza sativa L. on cognitive function.

Cyanidin-3-glucoside inhibits amyloid β₂₅₋₃₅-induced neuronal cell death in cultured rat hippocampal neurons

Increasing evidence implicates changes in [Ca²⁺]i and oxidative stress as causative factors in amyloid beta (Aβ)-induced neuronal cell death. Cyanidin-3-glucoside (C3G), a component of anthocyanin, has been reported to protect against glutamate-induced neuronal cell death by inhibiting Ca²⁺ and Zn²⁺ signaling. The present study aimed to determine whether C3G exerts a protective effect against Aβ₂₅₋₃₅-induced neuronal cell death in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague-Dawley rats using MTT assay for cell survival, and caspase-3 assay and digital imaging methods for Ca²⁺, Zn²⁺, MMP and ROS. Treatment with Aβ25–35 (20 µM) for 48 h induced neuronal cell death in cultured rat pure hippocampal neurons. Treatment with C3G for 48 h significantly increased cell survival. Pretreatment with C3G for 30 min significantly inhibited Aβ₂₅₋₃₅-induced [Zn²⁺]i increases as well as [Ca²⁺]i increases in the cultured rat hippocampal neurons. C3G also significantly inhibited Aβ₂₅₋₃₅-induced mitochondrial depolarization. C3G also blocked the Aβ₂₅₋₃₅-induced formation of ROS. In addition, C3G significantly inhibited the Aβ₂₅₋₃₅-induced activation of caspase-3. These results suggest that cyanidin-3-glucoside protects against amyloid β-induced neuronal cell death by reducing multiple apoptotic signals.

Black Rice (Oryza sativa L., Poaceae) Extract Reduces Hippocampal Neuronal Cell Death Induced by Transient Global Cerebral Ischemia in Mice

Rice is the most commonly consumed grain in the world. Black rice has been suggested to contain various bioactive compounds including anthocyanin antioxidants. There is currently little information about the nutritional benefits of black rice on brain pathology. Here, we investigated the effects of black rice (Oryza sativa L., Poaceae) extract (BRE) on the hippocampal neuronal damage induced by ischemic insult. BRE (300 mg/kg) was orally administered to adult male C57BL/6 mice once a day for 21 days. Bilateral common carotid artery occlusion (BCCAO) was performed for 23 min on the 8th day of BRE or vehicle administration. Histological analyses conducted on the 22nd day of BRE or vehicle administration revealed that administering BRE profoundly attenuated neuronal cell death, inhibited reactive astrogliosis, and prevented loss of glutathione peroxidase expression in the hippocampus when compared to vehicle treatment. In addition, BRE considerably ameliorated BCCAO-induced memory impairment on the Morris water maze test from the 15th day to the 22nd day of BRE or vehicle administration. These results indicate that chronic administration of BRE is potentially beneficial in cerebral ischemia.

Efficient Isolation of Dihydrophaseic acid 3′-O-β-D-Glucopyranoside from Nelumbo nucifera Seeds Using High-performance Countercurrent Chromatography and Reverse-phased High-performance Liquid Chromatography

High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed to isolate dihydrophaseic acid 3′-O-β-D-glucopyranoside (DHPAG) from the extract of Nelumbo nucifera seeds. Enriched DHPAG sample (2.3 g) was separated by HPCCC using ethyl acetate/n-butanol/water system (6:4:10, v/v/v, normal-phase mode, flow rate: 4.0 mL/min) to give 23.1 mg of DHPAG with purity of 88.7%. Further preparative RP-HPLC experiment gave pure DHPAG (16.3 mg, purity > 98%). The current study demonstrates that utilization of CCC method maximizes the isolation efficiency compared with that of solid-based conventional column chromatography.

Chemical Constituents of Nelumbo nucifera Seeds

The phytochemical study for the extract of Nelumbo nucifera (Nymphaceae) seeds has led to the isolation of ten compounds including five simple phenolic compounds, two indole derivatives, a flavonoid glycoside, two abscisic acid derivatives. The interpretation of 1D and 2D NMR and ESI-Q-TOF-MS spectroscopic data revealed the chemical structures of isolates to be p-hydroxybenzoic acid (1), protocatechuic acid (2), (E)-p-coumaric acid (3), (E)-ferulic acid (4), (E)-sinapate-4-O-β-D-glucopyranoside (5), tryptophan (6), 3-indoleacetic acid (7), isoschaftoside (8), dihydrophaseic acid (9), dihydrophaseic acid 3′-O-β-D-glucopyranoside (10). To the best of our knowledge, 1 – 5 and 7 were identified for the first time from N. nucifera seeds, and the presence of dihydrophaseic acid (9) and its glucoside (10) were demonstrated secondly in this plant.

Isolation And Development Of Quantification Method For Cyanidin-3-glucoside And Cyanidin-3-rutinoside In Mulberry Fruit By High-performance Countercurrent Chromatography And High-performance Liquid Chromatography

Cyanidin-3-glucoside (C3G) and cyanidin-3-rutinoside (C3R) were isolated by high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of tert-butyl methyl ether/n-butanol/acetonitrile/water/trifluoroacetic acid (1 : 3 : 1 : 5 : 0.01, v/v) to give pure C3G (34.1 mg) and C3R (14.3 mg) from 1.5 g crude mulberry fruit extract. Using the pure C3G and C3R, a reliable high-performance liquid chromatography (HPLC) method was developed and validated to determine the C3G and C3R contents in mulberry fruit. C3G and C3R were separated simultaneously using an Eclipse XDB-C18 column (4.6 x 250 mm I.D., 5 microm) coupled with a photodiode array detector (PDA). The gradient elution of the mobile phase consisting of acetonitrile (0.5% formic acid) and water (0.5% formic acid) was applied (1.0 mL/min), and the detection wavelength was 520 nm. The calibration curves of C3G and C3R showed good linearity (both with r2 = 0.9996) in the concentration range 15.625 - 500 microg/mL, and the relative standard deviations (RSD%) of intra- and interday variability were in the ranges 2.1 - 8.2% and 4.1 - 17.1%, respectively. The accuracies were ranged 96.5 - 102.6% for C3G and C3R, respectively. The developed HPLC method was used to determine the contents of C3G and C3R in newly harvested mulberry from eight different provinces of Korea.

Rapid Isolation of Cyanidin 3-Glucoside and Peonidin 3-Glucoside from Black Rice (Oryza sativa) Using High-Performance Countercurrent Chromatography and Reversed-Phase Column Chromatography

Anthocyanins are water soluble plant pigments which are responsible for the blue, red, pink, violet colors in several plant organs such as flowers, fruits, leaves and roots. In recent years, anthocyanin-rich foods have been favored as dietary supplements and health care products due to diverse biological activities of anthocyanins including antioxidant, anti-allergic, anti-diabetic, anti-microbial, anti-cancer and preventing cardiovascular disease. High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase medium pressure liquid chromatography (RP MPLC) method was applied for the rapid and efficient isolation of cyanidin 3-glucoside (C3G) and peonidin 3-glucoside (P3G) from black rice (Oryza sativa L., Poaceae). The crude black rice extract (500 mg) was subjected to HPCCC using two-phase solvent system composed of tert-butyl methyl ether/n-butanol/acetonitrile/0.01% trifluoroacetic acid (TBME/B/A/0.01% TFA, 1 : 3 : 1 : 5, v/v, flow rate - 4.5 mL/min, reversed phase mode) to give enriched anthocyanin extract (37.4 mg), and enriched anthocyanin extract was sequentially chromatographed on RP-MPLC to yield C3G (16.5 mg) and P3G (8.7 mg). The recovery rate and purity of isolated C3G were 76.0% and 98.2%, respectively, and those of P3G were 58.3% and 96.3%, respectively. The present study indicates that HPCCC coupled with RP-MPLC method is more rapid and efficient than multi-step conventional column chromatography for the separation of anthocyanins.

Phenolic Compounds and Triterpenes from the Barks of Diospyros burmanica

Diospyros burmanica Kurz. is an evergreen deciduous tree distributed in Mandalay of Myanmar, which belongs to the family of Ebenaceae. In Myanmar, it has been used to treat diarrhea, diabetes, diabetes and also as lumbers. In this study, seven flavonoids (1 - 7), a phenolic compound (8), and five triterpenes (9 - 13) were isolated from the barks of D. burmanica and their chemical structures were elucidated. Isolates were identified to be (+)-catechin (1), (+)-catechin 3-O-alpha-L-rhamnopyranoside (2), (+)-catechin 3-O-gallate (3), (-)-epicatechin (4), (-)-epicatechin 3-O-gallate (5), (+)-afzelechin 3-O-alpha-L-rhamnopyranoside (6), (+)-2,3-trans-dihydrokaempferol 3-O-alpha-L-rhamnopyranoside (7), methyl gallate (8), lupeol (9), methyl lup-20(29)-en-3-on-28-oate (10), beta-amyrin (11), alpha-amyrin (12), 3beta-hydroxy-D:B-friedo-olean-5-ene (13) through MS, 1H NMR and 13C NMR spectroscopic evidences.