phytochemistry

Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): A review of recent research.: Food Chem Toxicol. 2007 Sep 18; Ali BH, Blunden G, Tanira MO, Nemmar A

Ginger (Zingiber officinale Roscoe, Zingiberacae) is a medicinal plant that has been widely used in Chinese, Ayurvedic and Tibb-Unani herbal medicines all over the world, since antiquity, for a wide array of unrelated ailments that include arthritis, rheumatism, sprains, muscular aches, pains, sore throats, cramps, constipation, indigestion, vomiting, hypertension, dementia, fever, infectious diseases and helminthiasis. Currently, there is a renewed interest in ginger, and several scientific investigations aimed at isolation and identification of active constituents of ginger, scientific verification of its pharmacological actions and of its constituents, and verification of the basis of the use of ginger in some of several diseases and conditions. This article aims at reviewing the most salient recent reports on these investigations. The main pharmacological actions of ginger and compounds isolated therefrom include immuno-modulatory, anti-tumorigenic, anti-inflammatory, anti-apoptotic, anti-hyperglycemic, anti-lipidemic and anti-emetic actions. Ginger is a strong anti-oxidant substance and may either mitigate or prevent generation of free radicals. It is considered a safe herbal medicine with only few and insignificant adverse/side effects. More studies are required in animals and humans on the kinetics of ginger and its constituents and on the effects of their consumption over a long period of time.

Direct NMR analysis of cannabis water extracts and tinctures and semi-quantitative data on Delta(9)-THC and Delta(9)-THC-acid.: Phytochemistry. 2007 Oct 25; Politi M, Peschel W, Wilson N, Zloh M, Prieto JM, Heinrich M

Cannabis sativa L. is the source for a whole series of chemically diverse bioactive compounds that are currently under intensive pharmaceutical investigation. In this work, hot and cold water extracts as well as ethanol/water mixtures (tinctures) of cannabis were compared in order to better understand how these extracts differ in their overall composition. NMR analysis and in vitro cell assays of crude extracts and fractions were performed. Manufacturing procedures to produce natural remedies can strongly affect the final composition of the herbal medicines. Temperature and polarity of the solvents used for the extraction resulted to be two factors that affect the total amount of Delta(9)-THC in the extracts and its relative quantity with respect to Delta(9)-THC-acid and other metabolites. Diffusion-edited (1)H NMR (1D DOSY) and (1)H NMR with suppression of the ethanol and water signals were used. With this method it was possible, without any evaporation or separation step, to distinguish between tinctures from different cannabis cultivars. This approach is proposed as a direct analysis of plant tinctures.

The role of alkamides as an active principle of echinacea.: Planta Med. 2007 Jun;73(7):615-23 Authors: Woelkart K, Bauer R

Alkamides are the major lipophilic constituents of ECHINACEA preparations, which are widely used in some European countries and in North America for common colds. In earlier investigations they have been shown to possess stimulatory effects on phagocytosis. Recent experiments have demonstrated that alkamides are detectable in human blood in relevant concentrations after oral administration of Echinacea preparations. Alkamides show structural similarity with anandamide, an endogenous ligand of cannabinoid receptors. Consequently, it was found that alkamides bind significantly to CB (2) receptors, which is now considered as a possible molecular mode of action of Echinacea alkamides as immunomodulatory agents. It was also demonstrated recently in several studies that alkamide-containing Echinacea preparations trigger effects on the pro-inflammatory cytokines. They were therefore suggested as a new class of cannabinomimetics. However, the therapeutic relevance of these findings is still not clear as clinical studies on the common cold show contradictory results. Among the many pharmacological properties reported, investigations concerning herb-drug interactions have been neglected for a long time. Latest research concludes that prolonged use of Echinacea poses a minimal risk for co-medications metabolized by the P450 enzymes.

PMID: 17538868 [PubMed - indexed for MEDLINE]

Red American ginseng: ginsenoside constituents and antiproliferative activities of heat-processed Panax quinquefolius roots.: Planta Med. 2007 Jun;73(7):669-74 Authors: Wang CZ, Aung HH, Ni M, Wu JA, Tong R, Wicks S, He TC, Yuan CS

Red Asian ginseng ( Panax ginseng C. A. Meyer, Araliaceae) is used in many Oriental countries. In this study, the saponin constituents and anticancer activities of steamed American ginseng ( Panax quinquefolius L.) roots were evaluated. The contents of 12 ginsenosides in the roots were determined using high performance liquid chromatography (HPLC). After the steaming treatment (100 - 120 degrees C for 1 h and 120 degrees C for 0.5 - 4 h), the quantity of 7 ginsenosides decreased and that of 5 others increased. The content of ginsenoside Rg3, a previously recognized anticancer compound, increased significantly when the root was steamed at 120 degrees C for 0.5 - 3 h. The antiproliferative effects of unsteamed and steamed (120 degrees C for 1 h and 2 h) American ginseng root extracts were assayed by the modified trichrome stain (MTS) method using three cancer cell lines (SW-480, HT-29, NSCLC). Heat-processing increased the antiproliferative effect of American ginseng significantly, and the activity of the extract from roots steamed for 2 h was greater than that of roots steamed for 1 h. Chemical constituents and antiproliferative activities of white and red Asian ginseng have also been evaluated. Five representative ginsenosides, Rb1, Rd, Re, Rg2 and Rg3, were studied. Ginsenoside Rg3 had the most potent effect. The antiproliferative activities of red American ginseng are augmented when ginsenoside Rg3 is increased.

PMID: 17538869 [PubMed - indexed for MEDLINE]

Role of advances in chromatographic techniques in phytochemistry.: Phytochemistry. 2007 Oct 9; Authors: Marston A

Chromatography is the lynchpin of phytochemistry and is the key to obtaining pure compounds for structure elucidation, for pharmacological testing or for development into therapeuticals. It also plays a fundamental role as an analytical technique for quality control and standardisation of phytotherapeuticals. Although liquid chromatography is barely 100 years old, an extraordinary variety of instrumental and ancillary equipment is available, notably in the domain of high-performance liquid chromatography. It is impossible to touch all areas of chromatography in such a review but certain areas are worthy of mention: HPLC, HPTLC, UPLC and countercurrent chromatography. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MS(n) and LC/NMR. These are indispensable nowadays for the early detection and identification of compounds in crude plant extracts.

PMID: 17931672 [PubMed - as supplied by publisher]

Pharmacokinetics and Metabolic Profile of Free, Conjugated and Total Silymarin Flavonolignans in Human Plasma after Oral Administration of Milk Thistle Extract.: Drug Metab Dispos. 2007 Oct 3; Authors: Wen Z, Dumas TE, Schrieber SJ, Hawke RL, Fried MW, Smith PC

Silymarin, a mixture of polyphenolic flavonoids extracted from milk thistle (Silybum marianum), is mainly composed of silychristin (SC), silydianin (SD), silybin A (SBA), silybin B (SBB), isosilybin A (ISBA), and isosilybin B (ISBB). In this study, the plasma concentrations of free (unconjugated), conjugated (sulfated and glucuronidated), and total (free and conjugated) silymarin flavonolignans were measured using a liquid chromatography-electrospray ionization-mass spectrometry, after a single oral dose of 600 mg standardized milk thistle extracts to three healthy volunteers. Pharmacokinetic analysis indicated that silymarin flavonolignans were rapidly eliminated with short half-lives (1 to 3 and 3 to 8 h for the free and conjugated, respectively). The AUC0-->infinity values of the conjugated silymarin flavonolignans were 4- to 30-fold higher than those of their free fractions, with SBB (mean AUC0-->infinity = 51 and 597 microg.h/l for the free and conjugated, respectively) and ISBA (mean AUC0-->infinity = 30 and 734 microg.h/l for the free and conjugated, respectively) exhibiting higher AUC0-->infinity values in comparison to other flavonolignans. Near the plasma peak times (1 to 3 h), the free, sulfated, and glucuronidated flavonolignans represented approximately 17, 28, and 55 % of the total silymarin, respectively. In addition, the individual silymarin flavonolignans exhibited quite different plasma profiles for both the free and conjugated fractions. These data suggest that, after oral administration, silymarin flavonolignans are quickly metabolized to their conjugates, primarily forming glucuronides, and the conjugates are primary components present in human plasma.

PMID: 17913795 [PubMed - as supplied by publisher]

[Study on influence of processing methods on chemical constituents in Radix Paeoniae Alba]: Zhongguo Zhong Yao Za Zhi. 2006 Sep;31(17):1418-21 Authors: Wang Q, Liu RX, Guo HZ, Zhu ZN, Bi KS, Guo DA

OBJECTIVE: The influence of processing methods on chemical constituents in Radix Paeoniae Alba was observed. METHOD: A HPLC method was used for analyzing the changes of eight major constituents, namely gallic acid, paeoniflorin sulfonate, catechin, paeoniflorin sulfonate, albiflorin, paeoniflorin, benzoic acid, pentagalloylglucose and benzoylpaeoniflorin, with the three processing procedures of decorticating, boiling and fumigating by burning of sulphur. Analysis was performed using a Zorbax SB-C18 column (4.6 mm x 250 mm, 5 microm) with the mixture of acetonitrile (A) and 0.015% phosphoric acid solution as mobile phase in gradient mode. The detection wavelength was set at 230 nm and the column temperature was at 30 degrees C. RESULT: Except for gallic acid and pentagalloylglucose, the other constituents decreased during procedure of decorticating and boiling. Fumigating by burning of sulphur would produce a new compound, paeoniflorin sulfonate, which was a byproduct from the reaction of paeoniflorin with SO2. CONCLSION: The significant changes were produced in chemical constituents of Radix Paeoniae Alba during three processing procedures. Therefore, the processing of Radix Paeoniae Alba should be strictly controlled and standardized.

PMID: 17087079 [PubMed - indexed for MEDLINE]

A new glycoside from Alpinia officinarum.: Yao Xue Xue Bao. 2006 Mar;41(3):233-5 Authors: An N, Lin J, Yang SL, Zou ZM, Xu LZ

AIM: To investigate the glycosidic constituents in the rhizomes of Alpinia officinarum Hance. METHODS: The isolation and purification of glycosides were done with column chromatography on macro porous resin, polyamides and Sephadex LH-20, whilst the structure elucidation was done by HRCI-MS and NMR (1D and 2D) methods. RESULTS: A glycosidic ester identified as 4'-hydroxy-2'-methoxyphenol-beta-D-{6-0-[4"-hydroxy-3", 5"-dimethoxy (benzoate)]}-glucopyranoside (I), along with a known compound n-butyl-beta-D-fructopyranoside (II), were isolated and characterized. CONCLUSION: I was found to be a new compound, named as alpinoside A, whilst II was isolated from the genus Alpinia for the first time.

PMID: 16758994 [PubMed - indexed for MEDLINE]

Medicinal chemistry endeavors around the phytocannabinoids.: Chem Biodivers. 2007 Aug;4(8):1707-28 Authors: Stern E, Lambert DM

Over the past 50 years, a considerable research in medicinal chemistry has been carried out around the natural constituents of Cannabis sativa L. Following the identification of Delta9-tetrahydrocannabinol (Delta9-THC) in 1964, critical chemical modifications, e.g., variation of the side chain at C3 and the opening of the tricyclic scaffold, have led to the characterization of potent and cannabinoid receptor subtype-selective ligands. Those ligands that demonstrate high affinity for the cannabinoid receptors and good biological efficacy are still used as powerful pharmacological tools. This review summarizes past as well as recent developments in the structure-activity relationships of phytocannabinoids.

PMID: 17712816 [PubMed - indexed for MEDLINE]

Plant natural products: back to the future or into extinction?: Phytochemistry. 2007 Jul;68(14):2015-22 Authors: McChesney JD, Venkataraman SK, Henri JT

Natural product substances have historically served as the most significant source of new leads for pharmaceutical development. However, with the advent of robotics, bioinformatics, high throughput screening (HTS), molecular biology-biotechnology, combinatorial chemistry, in silico (molecular modeling) and other methodologies, the pharmaceutical industry has largely moved away from plant derived natural products as a source for leads and prospective drug candidates. Can, or will, natural products ever recapture the preeminent position they once held as a foundation for drug discovery and development? The challenges associated with development of natural products as pharmaceuticals are illustrated by the Taxol story. Several misconceptions, which constrain utilization of plant natural products, for discovery and development of pharmaceuticals, are addressed to return natural products to the forefront.

PMID: 17574638 [PubMed - indexed for MEDLINE]