Organic chemistry

The content of polyphenols in Fumaria officinalis L. and Fumaria thuretii Bioss. from two different
populations, naturally grown in Bulgaria has been studied. Significant differences between concentrations of
main polyphenols (rutin, hyperoside and syringic acid) and antioxidant activity in two different populations of
both analyzed species were not established (RSD 2-14%). Stability of secondary metabolism of F. officinalis
and F. thuretii indicates for genetic stability of Bulgarian Fumaria species growing in different populations.

The current research is dedicated to following the accumulation of prebiotics inulin and fructooligosaccharides in the roots of Bulgarian medicinal plants common chicory (Cichorium intybus L.), dandelion (Taraxacum officinale Web.) and meadow salsify (Tragopogon pratensis L.) in some areas of the Bulgaria for a period of two years. The roots of each plant were subjected to exhausting ethanol and subsequent water extraction. The contents of inulin-type fructans in the obtained extracts have been determined by a spectrophotometric method based on resorcinol reaction and TLC analysis. It has been found that the amounts of fructooligosaccharides and inulin were the highest in roots of the plants collected in the autumn season as in taproots of common chicory reached to 23 g/100 g dw and up to 34 g/100 g d.w in dandelion roots, respectively. The underground parts of the studied medicinal plants collected in the spring have been characterized by very high levels of fructo-oligosaccharides and sugars. Meadow salsify showed relatively constant levels of fructans in its taproots (18 g/100g d.w).
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Fatty esters of carbohydrates constitute an interesting group of non-ionic surfactants. These compounds are environmentally friendly, with low toxicity and present interest in agriculture, pharmaceuticals, cosmetic and food industry. Inulin and fructooligosaccharides esters were synthesized by reacting these carbohydrates with methyl esters of saturated fatty acids (C12 to С18). The esterification reaction was performed in presence of catalyst NaOMe and absence of solvent. A new method for synthesis with the ultrasonic influence has been developed and applied. The fructooligosaccharides esters and modified inulin have been characterized by measurement of melting point, water activity, thin-layer chromatography (TLC) and FT-IR. A preliminary study of their emulsifying and stabilizing properties was analyzed. The rheological properties, dispersion and emulsion stability of oil-in-water emulsions (O/W) prepared with different concentration of inulin esters as emulsifier were investigated.

Fumaria plants have been traditionally used against skin diseases, as diuretics, laxatives, hepatoprotectants and etc. Their biological activity is associated with the presence of isoquinoline alkaloids, while polyphenols are not investigated well in this context. Polyphenols could increase the added value of medicinal plants extracts by enhancing their antioxidant activity or improving overall biological activities. The presented study evaluated the polyphenolic contents and antioxidant activities of extracts of five Bulgarian Fumaria species (Fumariaceae): Fumaria officinalis L., Fumaria thuretii Boiss., Fumaria kralikii Jord., Fumaria rostellata Knaf. and Fumaria schrammii (Asch) Velen. Qualitative and quantitative determinations of phenolic acids and flavonoids were performed by HPLC system with UV-detection. Antioxidant activity of extracts was evaluated by four popular spectrophotometric methods (DPPH, ABTS, FRAP and CUPRAC). The total phenolic content was the highest in extract of F. officinalis with quercetin (0.49 ± 0.03 mg/g DW), p-coumaric (1.10 ± 0.03 mg/g DW) and ferulic (2.35 ± 0.04 mg/g DW) acids as major compounds. Theses extracts also showed the highest antioxidant activity among the investigated plants. Our data reveal new possibilities to expand applications of Fumaria extracts from a local ethnomedicine drug to new industrial fields such as foods and cosmetics preservation.

A rapid and sensitive spectrophotometric method for the quantitative determination of inulin and fructooligosacharides in lactic acid fermented dairy products has been developed. The method was based on the familiar Seliwanoff reaction for detection of ketoses with resorcinol in hydrochloric acid media. The standard curve was constructed by using fructose as a standard. The tested spectrophotometric method has been characterized with good linearity (R2=0.997) in the fructose concentration range 0.5-20 μg/ml. The presence of galactose and lactose in the analyzed samples did not interfere in the determination of inulin. The sample preparation procedure included hot water extraction, purification by Carrez solutions and subsequent spectrophotometric determination at 480 nm. The developed method showed very good precision: repeatability (RSD=6%) and reproducibility (RSD=10%). The obtained results demonstrated that the spectrophotometric method is less time-consuming, cheap, reproducible and suitable for routine laboratory analysis.

Ficus carica L. belongs to the family Moraceae. It is commonly known as fig, which is a medium sized
deciduous tree widely distributed in sub-tropical and tropical countries. It has been used as fruit and medicine
for several centuries. Phytoconstituents like flavonoids, phenolics, fatty acis, proanthocyanidine, anthocyanins,
phytosteroles (campesterol, stigmasterol, sitosterol), xanthotoxin, psoralens, bergapten, xanthotoxol have been
extracted from leaves and fruits, and peptides from latex. Traditionally the fruit extracts possessed
hypoglycemic, diuretic, expectorant, antioxidant, immunity, anthelmintic, hepetoprotective activities, latex has
anthelmintic and anticarcinogenic. The present review is therefore, an effort to give a detailed survey of the
literature on its pharmacognosy, phytochemistry, and pharmacological properties.

The purpose of the present study was to investigate the antioxidant activity and fructans content in ethanol and water extracts of roots of elecampane (Inula helenium L.), a Bulgarian medicinal plant. The extraction procedure included 95% (v/v) ethanol extraction and subsequent water treatment. The antioxidant activity was evaluated by several reliable methods such as DPPH-, ABTS-, FRAP- and CUPRAC-assays, as well as the total phenolic content. In addition, the total fructans and sugar content were determinated by spectrophotomeric, TLC and HPLC-RID methods. The level of fructans in ethanol extracts was 14.1 g / 100 g dry weight, as nystose and 1-kestose were only 0.3 g / 100 g dry weight, and 0.5 g / 100g dry weight, respectively. The absence of fructooligosacharides and sugars in water extracts after the ethanol pretreatment was established. Inulin content was evaluated to be 32 g / 100 g dry weight. The metabolites profile of roots revealed their potential application as radical scavengers due to the presence of polyphenols. Therefore, the root extracts of elecampane could be assumed as a rich source of biologically active substance, in particular dietary fiber with potential prebiotic effect, due to the presence of polysaccharide inulin and fructooligosacharides.

Ficus carica L. (fig) belongs to mulberry tree (Moraceae) which is one of the oldest fruits in the world. The extracts from fig possess anthelmintic, anticarcinogenic, purgative, aphrodisiac, anti-inflammatory, expectorant, diuretic, anti-anxiety (mild sedative) activity. Phytoconstituents as umbelliferone, scopoletin, psoralens, bergapten, xanthotoxin, xanthotoxol, marmesin have been isolated from fig leaves. The current study was conducted to evaluate the total polyphenols, total flavonoids (TF), and to investigate the antioxidant capacities of aqueous, methanolic, ethanolic, acetone and n-hexane extracts prepared from Ficus carica leaves. Total phenolic content (TFC) was determined by using the Folin-Ciocalteau method. The antioxidant capacities were evaluated by DPPH and FRAP spectrophotometric methods. The results indicated that TPC, TF, DPPH and FRAP values were higher in aqueous extract of Ficus carica leaves: 6.6 mg GAE / g DW, 2.1 mg QE / g DW, 59.6 mM TE / g DW (DPPH method) and 53.9 mM TE / g DW (FRAP method), respectively. The results clearly demonstrated that these extracts had antioxidant capacity and it could be find significant correlation between total phenolic content and antioxidant activity. Therefore, Ficus carica leaves were evaluated as a rich source of polyphenols and they possessed high antioxidant properties.

Fragaria vesca L. (wild strawberry) belongs to the Rosaceae family. The leaves and roots from wild strawberry are
herbal materials applied in traditional medicine. Fragaria vesca are rich source of biologically active substances like
tannins, procyanidins, anthocyanidins, flavonoids and phenolic acids. The aim of this study was to compare the value of
phytochemical compounds and antioxidant activities in infusion and decoction obtained from the wild strawberry
leaves. The extracts were analyzed regarding their secondary metabolite content (total polyphenols, total flavonoids
and total proanthocyanidins) and antioxidant activities (DPPH and CuPRAC methods). The analysis of decoction
extracts from the leaves harvested in blooming period revealed the highest level of total polyphenols (46.1 mg GAE/g
DW), total flavonoids (4.7 mg QE/ g DW), total proantocyanidines (22.3 mg/ g DW) and antioxidant activities – radical
scavenging activity (DPPH – 325.0 mM TE/ g DW) and metal reducing ability (CuPRAC – 1257.9 mM TE/ g DW). The
results showed that the water extracts from leaves of Fragaria vesca are appropriate additives for preparation of
functional foods and natural cosmetic products with improved biological activity.

Сукроестерите представляват нейоногенни повърхностно-активни вещества с важно значение в растителната защитата, медицината, козметиката и хранителната промишленост. Освен регламентираното им приложение като добавки в храните (емулгатори), те се утвърдиха и като вещества с потенциална антимикробната активност. Настоящият преглед има за цел да разгледа новите подходи прилагани при синтеза на естери на захарозата, характеризиращи се с повишена биологична активност. Химичният синтез на сукроестери (каприлати, лаурати, миристати и палмитати) обикновено се осъществява в DMSO чрез преестерификация с винилови или етилови естери на съответните мастни киселини в присъствие на алкални катализатори. В настоящия обзор е направена сравнителна характеристика на новите химични и ензимни методи за естерификация на захароза. Подробно са разгледани ускореният ултразвуков химичен синтез на сукроестери, както и ензимна модификация, осъществена в присъствие на липаза, проведена под микровълново, ултразву...

Abstract Ultrasonic fractional extraction of fructooligosaccharides and inulin from Jerusalem artichoke tubers has been carried out. The following conditions as the type of the used solvent- n-propanol, 95% (v/v) ethanol and distilled water and the duration of the extraction process have been varied. The contents of sugars and fructans in the obtained extracts were determinated by spectrophotometric method based on resorcinol reaction and by TLC analysis. The greatest amounts of fructooligosaccharides and inulin have been extracted by distilled water (46 g/100g d.w.), as each ultrasonic extraction was carried out in triplicate for 30 min. The best solvent used for the separation of a particular fraction fructooligosaccharides consisting of kestose, nystose and fructofuranosylnystose was n-propanol.

This article presents the results obtained by the ultrasound-assisted synthesis of sucrose and fructooligosaccharides (FOS) esters with fatty acids (palmitic and 10-undecylenic), the identification of the products and the study of their possible application as plasticizers in plastics processing. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 13C NMR) spectroscopy were used to identify the synthesized carbohydrate esters. The plasticizing effect of the sucrose palmitate applied in polyvinyl chloride (PVC) was evaluated by the glass transition temperatures; the decrease of the Tg with the increase of the ester content could be accepted as confirmation of the esters’ plasticizing effect. The antimicrobial activity of the synthesized sucrose and FOS esters was evaluated; the results allowed us to conclude that the 10-undecynoyl esters of sucrose and fructooligosaccharides could be successfully applied as potential antimicrobial agents, as well. The sucrose palmitate plasticizing effect was evaluated by determining the glass transition temperatures of thin polyvinyl chloride films on the basis of differential scanning calorimetry (DSC) and changes of mechanical properties. The results showed a decrease of the glass transition temperature with the increase of the ester content, which confirmed the plasticizing effect of the obtained esters.