Ljuba Evstatieva

Quantitative analysis of sesquiterpene lactones in extract of Arnica montana L. by 1H NMR spectroscopy

(1)H NMR spectroscopy was used as a method for quantitative analysis of sesquiterpene lactones present in a crude lactone fraction isolated from Arnica montana. Eight main components - tigloyl-, methacryloyl-, isobutyryl- and 2-methylbutyryl-esters of helenalin (H) and 11α,13-dihydrohelenalin (DH) were identified in the studied sample. The method allows the determination of the total amount of sesquiterpene lactones and the quantity of both type helenalin and 11α,13-dihydrohelenalin esters separately. Furthermore, 6-O-tigloylhelenalin (HT, 1), 6-O-methacryloylhelenalin (HM, 2), 6-O-tigloyl-11α,13-dihydrohelenalin (DHT, 5), and 6-O-methacryloyl-11α,13-dihydrohelenalin (DHM, 6) were quantified as individual components.

Chemical composition of the essential oils of Rhodiola rosea L. of three different origins

Rhodiola rosea L. (Crassulaceae), or “rose root” is a perennial herbaceous plant, distributed in the Northern Hemisphere. Pharmacological studies have shown that R. rosea exhibits different biological activities – antioxidant, antidepressant, anticancer, etc. The aim of this study was to compare the chemical composition of essential oils from rhizomes of three commercial samples of R. rosea originated from Bulgaria (sample 1), China (sample 2) and India (sample 3). The oils were analyzed by GC and GC-MS. Thus, the main volatile component in the Bulgaria and Chinese R. rosea was geraniol, followed by myrthenol in sample 1 or octanol in sample 2. Phenethylalcohol was a principal constituent in the Indian oil. Myrtenol and octanol were in significant amounts too. Aliphatic hydrocarbons were characteristic of the latter sample. It is notable that cinnamyl alcohol, which was present in large concentration in Bulgarian sample, was not detected in the other two samples. The obtained results showed considerable differences in the composition of the studied three origins of R. rosea.

Volatiles from Four Astragalus Species: Phenological Changes and their Chemotaxonomical Application

This paper shows the changes of the volatile compounds from four Astragalus species at three phenological stages: leaf development, flowering and fructification, which might be connected with the plant defense. After GC/MS analyses of Astragalus glycyphyllos L., A. hamosus L., A. cicer L. and A. spruneri Boiss., different groups of volatile compounds were found: hydrocarbons, alcohols, aldehydes and ketones, esters, terpenes, chlorinated compounds, etc. Identified volatiles were used for a cluster analysis in order to make chemotaxonomic conclusions for these evolutionary different species.

Two iridoid glucosides, 5-O-Menthiafoloylkickxioside and kickxin, from Kickxia Dum. species

Abstract The iridoid compositions of Kickxia elatine, K. spuria and K. commutata were studied. Two new iridoid glucosides, 5-O-menthiafoloylkickxioside and the dimer kickxin, were isolated. Their structures were elucidated on the basis of spectral and chemical data. The structure of kickxin has been determined as an ester of mussaenosidic acid and antirrinoside between C-11 and C-6. Additionally, five known iridoid glucosides—kickxioside, antirrinoside, linarioside, antirride and mussaenosidic acid, were isolated and identified. The latter two iridoids were found for the first time in Kickxia species.

Iridoid glucosides from Phlomis tuberosa L. and Phlomis herba-ventis L.

Abstract A new iridoid glucoside, 5-desoxysesamoside, was isolated from Phlomis tuberosa L. (Lamiaceae) together with three known iridoid glucosides sesamoside, shanziside methyl ester and lamalbid. Lamiide was found in P. herba-ventis ssp. pungens in high concentrations.

Bioactive chemical constituents from Smilax excelsa

Plants from the genus Smilax are used to treat syphilis, acute bacillary dysentery, acute and chronic nephritis, eczema, dermatitis, cystitis, and mercury and silver poisoning [1, 2]. Several species from this genus have demonstrated antimutagenic [3], antioxidant [4], anti-inflammatory, and anti-nociceptive activities [5]. A survey of the literature showed that several Smilax species contain phenylpropanoid glycosides [3], anthocyanins [6], flavanoid glucosides [2], and steroidal saponins [7, 8]. We investigated the constituents of the rhizomes of Smilax excelsa, a climbing shrub growing in Bulgaria. In this paper we report the isolation and structural identification of trans-resveratrol (1) [9], naringenin (2) [10], 5-O-caffeoylshikimic acid (3) [11], 1-O-trans-feruloylglycerol (4) [12], 1-O-trans-p-coumaroylglycerol (5) [12], and 1,2-O-di-trans-feruloylglycerol (6) [12]. The antimicrobial and cytotoxic activities of the methanol, chloroform, n-butanol, and water-methanol extracts were tested.

Complex Investigations of Tribulus Terrestris L. for Sustainable use by Pharmaceutical Industry

ABSTRACT Tribulus terrestris L. (Zygophyllaceae) is an annual medicinal plant, commonly known as Puncture vine. The Project “Complex investigations of Tribulus terrestris L. for sustainable use by pharmaceutical industry” supported by the National Science Fund of Bulgaria was launched in 2008. The studies were focused on the distribution of economically valuable genotypes and their resources in habitats, including protected zones of NATURA 2000. Also their threatening as a result of human activities and climatic changes was investigated. Phytochemical study and method development for the analysis and standardization of samples was performed. The content of the main saponins and their variability in habitats were investigated. Assessment of the physiological status, regulation of plant metabolism and gene expression were also performed. Improvement of the quality of plant material was achieved by using plant organic and mineral nutrition. The practical results of the project development are the evaluation and selection of perspective localities for collection of the plant material from the natural habitats and protocol development for the introduction and breeding of the species in field conditions. Conservation measures were proposed as a guarantee for the sustainable and rational use of Tribulus terrestris for resource purposes.

DISTRIBUTION AND RESOURCES EVALUATION OF TRIBULUS TERRESTRIS L. (ZYGOPHYLLACEAE) POPULATION IN THRACIAN FLORISTIC REGION

ABSTRACT Tribulus terrestris is an annual medicinal plant. Its row material is collected for industrial uses from the nature. The distribution of its populations as well as the quantity of the drug production (productivity) in specific sites and conditions were studied. Thirty three economically significant localities were established in the Thracian floristic region during 2009, distributed on area of 1314 dka, which could give about 90 tons of dry drug annually. The biomass production of every area was affected by the change in the environmental conditions. The best populations for collection and production of pharmaceutical drug and international trade were determined.

Irregular linear sesquiterpene dilactones from Anthemis auriculata Boiss.

Seven new irregular linear sesquiterpene lactones, epi-antheindurolide A (1), epi-antheindurolide A-5,6-oxide (2), 5-hydroxy-5,6-dihydro-6,13-dehydro-epi-antheinduro lide A (3), 5-hydroperoxy-5,6-dihydro-6,13-dehydro-epi-antheindurolide A (4), epi-antheindurolide B (5), 6-hydroxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (6) and 6-hydroperoxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (7), were isolated from the flowers of Anthemis auriculata Bioss. Their structures were established by spectroscopic techniques. The discussed compounds were found to be stereoisomers of recently reported lactones for A. arvensis.

Seco-eremophilanolides from Senecio macedonicus

Four sesquiterpene lactones with seco-eremophilane skeleton have been isolated from the leaves of Senecio macedonicus, two of which are new C-8 epimeric secomacrotolides. Their structures were elucidated by spectral analysis.