scholarly journals Extraction of resinoids from St. John's wort (Hypericumperforatum L): II. Modeling of extraction kinetics

2002 ◽  
Vol 56 (2) ◽  
pp. 60-67 ◽  
Author(s):  
Vlada Veljkovic ◽  
Dragan Milenovic
Keyword(s):  
Plant Material ◽  
Film Theory ◽  
Solid Material ◽  
Operating Conditions ◽  
Solvent Ratio ◽  
Extraction Kinetics ◽  
Total Extract ◽  
St John’S Wort ◽  
Model Based ◽  
St John's Wort

The extraction of resinoids from St. John's wort (Hypericum perforatum L) was studied in a series of two papers. While the first part dealt with the effects of the operating conditions on the yield of resinoids (total extract) and process optimization, the mathematical models of extraction kinetics were analyzed in the second one. The extraction was carried out using an aqueous solution of ethanol (70 and 95 % v/v) at the hydromodulus (plant material to solvent ratio, w/v) of 1:5 or 1:10. The plant material was disintegrated and divided into three fractions (particle mean size 0.23, 0.57 and 1.05 mm). The temperature was 25, 50 or about 80?C (boiling temperature). Three models were applied for modeling the extraction kinetics: a model based on the film theory, a model based on unsteady state diffusion through solid material and the empirical Ponomarev equation. Because of its physical basis, the relative simplicity and good fitting of the experimental data, the model based on the film theory could be proposed for mathematical modeling of solid-liquid etraction processes.

scholarly journals Extraction of resinoids from St. John's wort (Hypericum perforatum L): I. Efficiency and optimization of extraction

2002 ◽  
Vol 56 (2) ◽  
pp. 54-59 ◽  
Author(s):  
Dragan Milenovic ◽  
Vlada Veljkovic ◽  
Branimir Todorovic ◽  
Miomir Stankovic
Keyword(s):  
Plant Material ◽  
Hypericum Perforatum ◽  
Ethanol Solution ◽  
Operating Conditions ◽  
Solvent Ratio ◽  
Total Extract ◽  
St John’S Wort ◽  
St John's Wort ◽  
Hypericum Perforatum L ◽  
Full Factorial

The extraction of resinoids from St. John's wort (Hypericum perforatum L) was studied in a series of two papers. In the first part, the effects of the operating conditions on the yield of resinoids (total extract) were analyzed, while the mathematical models of extraction kinetics were compared in the second one. The extraction was carried out using an aqueous solution of ethanol (70 and 95 % v/v) at a hydromodulus (plant material to solvent ratio, w/v) of 1:5 or 1:10. The plant material was disintegrated and divided into three fractions (mean particle size: 0.23, 0.57 and 1.05 mm). The temperature was 25, 50 or about 80?C (boiling temperature). A higher yield of resinoids was obtained when the plant material of greater disintegration degree (0.23 mm) was treated with 70% v/v aqueous ethanol solution at higher hydromoduli (1:10) and temperatures (80?C). The effects of the operating factors on the yield of resinoids were estimated by using both the full factorial experimental plan 24 and artificial neuronic networks (ANN) of 3-4-1 topology. Of the two methods, the ANN one was found to be advantageous because of its capability of estimating the yield of resinoids in the whole range of the applied operating conditions.

scholarly journals An investigation of CO2 extraction of marigold (Calendula officinalis L.)

2007 ◽  
Vol 72 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Lidija Petrovic ◽  
Zika Lepojevic ◽  
Verica Sovilj ◽  
Dusan Adamovic ◽  
Vele Tesevic
Keyword(s):  
Essential Oil ◽  
Plant Material ◽  
Oil Content ◽  
Steam Distillation ◽  
Calendula Officinalis ◽  
Extraction Kinetics ◽  
Total Extract ◽  
High Pressure Co2 ◽  
The One ◽  
Calendula Officinalis L

Essential oil content (0.05 %) of marigold (Calendula officinalis L.) was determined using the official steam distillation procedure. High-pressure CO2 extraction of plant material under supercritial (100, 200 and 300 bar and 40?C) and subcritical (60, 90 and 120 bar and 15?C) conditions for 3 h was investigated. It was found that the increase in the pressure promoted an increase in the yield. The essential oil contents obtained from the investigated CO2 extracts by steam distillation were significantly higher (1.52-2.70 times) and increased with pressure. Major constituents of the oil, identified using GC-MS and GC-FID, were ?-cadinol (26.54 %), T-cadinol and T-muurolol (9.80 %), ?-cadinene (2.99 %), hexadecanoic acid (2.95 %), and ledane (2.45 %). In addition, the essential oils of the CO2 extracts contained ?-cadinene (6.50-19.87 % under supercritical and 16.09-19.41 % under subcritical conditions), which was not found in the essential oil obtained from the plant by steam distillation. The extraction kinetics was investigated at 200 bar and 40 ?C. The total extract obtained after 10 h of extraction was 6.54 % and essential oil content in it, refering to plant material, was 0.209 %, which is 4.16 time more than the one determined by the standard steam distillation procedure.

scholarly journals The content of heavy metals in the leaves of Hypericum perforatum L. on serpentinite soils in Serbia

2008 ◽  
pp. 143-153 ◽  
Author(s):  
Dragica Obratov-Petkovic ◽  
Ivana Bjedov ◽  
Snezana Belanovic
Keyword(s):  
Heavy Metals ◽  
Plant Material ◽  
Hypericum Perforatum ◽  
Native Plants ◽  
Chemical Elements ◽  
St John’S Wort ◽  
Nickel Chromium ◽  
St John's Wort ◽  
Iron Nickel ◽  
Hypericum Perforatum L

St John's wort is one of the best known and used medicinal plants. The demands for St John's wort in Serbia is still supplied by the collection of native plants. Therefore it was necessary to examine the concentration of heavy metals in the soil and in plant material on serpentinites and to assess the potential safe harvesting and further utilisation of this plant species. The research was performed on three serpentinite sites in Serbia: Zlatibor, Divcibare and Goc. The main soil types were determined and the contents of 7 chemical elements were analyzed in the soil and in the plant material. It was determined that the soils of all three localities had increased concentrations of nickel, chromium and manganese. The St John's wort plant material (leaves) showed the increased concentrations of iron, nickel and chromium. It was concluded that St John's wort was a tolerant species regarding the heavy metal content, and it was recommended to avoid its harvesting on the investigated localities.

scholarly journals Antinociceptive Properties of St. John's Wort (Hypericum perforatum) and Other Hypericum Species

2016 ◽  
Vol 11 (11) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Nikola M. Stojanović ◽  
Niko S. Radulović ◽  
Pavle J. Randjelović ◽  
Darko Laketić
Keyword(s):  
Pain Relief ◽  
Plant Material ◽  
Hypericum Perforatum ◽  
Mechanisms Of Action ◽  
Experimental Models ◽  
Botanical Origin ◽  
Routes Of Administration ◽  
St John’S Wort ◽  
St John's Wort ◽  
Hypericum Species

This review aims at a coherent summary of the results obtained from various studies that concern analgesic-like activity of the extracts of H. preforatum L. and thirteen other Hypericum L. species (Hypericaceae). Botanical origin, plant organs and extraction modes of the plant material, experimental models, routes of administration and doses used for animal treatment are summarized. Mechanisms of action and substances (and even the synergy thereof) proposed so far to be responsible for the observed activity have also been discussed. Even though St. John's wort ( H. perforatum) is the most renowned plant species of this genus, it is neither the only nor the most potent one in inducing pain relief.

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