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Yuldashev, A. A.; Yuldashev, M. P.; Abdullabekova, V. N.

doi:10.1023/a:1020400615593

Cited by 9 publications

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“…The internal arrangement of the centers is adapted for certain requirements of electric and thermal consumers. Power is transmitted through adjacent networks, photovoltaic sources, connected to H3 center, and wind-powered turbines and hydroelectric power stations are connected to an electric network through the N4 hub [1,2]. This network can represent more remote hydroelectric power station near settlements and the cities where there are reservoirs for accumulation of energy of water or accumulators of energy of other type of BESS.…”

Section: Problem Definitionmentioning

confidence: 99%

Construction and optimization of a power complex with a distributed generation on the basis of renewables and methods of artificial intelligence (on the example of the Republic of Tajikistan)

Manusov

Kirgizov

Ahyoev

2016

E3S Web of Conferences

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Abstract. In this article the basic principles and classifications of small hydroelectric power stations depending on the power of system in which they work are provided. Especially, in the conditions of Tajikistan when all small hydroelectric power stations in some regions carry out the functions of big hydroelectric power stations. We suggest to use new classification by using function of fuzzy logic. The new concept of a power complex (HUB) on the basis of the renewed energy source (RES) is also offered.

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Section: Problem Definitionmentioning

confidence: 99%

Construction and optimization of a power complex with a distributed generation on the basis of renewables and methods of artificial intelligence (on the example of the Republic of Tajikistan)

Manusov

Kirgizov

Ahyoev

2016

E3S Web of Conferences

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“…et Vved. (Rutaceae) is indigenous to Uzbekistan and produces alkaloids [1a], flavonoids, and coumarins [2].The air-dried aerial part (1 kg) of this plant that was collected in Babataga Mountains on May 20, 2008, during budding was extracted with MeOH. The dry MeOH extract was distributed between aqueous H 2 SO 4 (10%) and CHCl 3 .…”

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confidence: 99%

“…et Vved. (Rutaceae) is indigenous to Uzbekistan and produces alkaloids [1a], flavonoids, and coumarins [2].…”

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Alkaloids from Haplophyllum leptomerum

2010

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The plant Haplophyllum leptomerum Lincz. et Vved. (Rutaceae) is indigenous to Uzbekistan and produces alkaloids [1a], flavonoids, and coumarins [2].The air-dried aerial part (1 kg) of this plant that was collected in Babataga Mountains on May 20, 2008, during budding was extracted with MeOH. The dry MeOH extract was distributed between aqueous H 2 SO 4 (10%) and CHCl 3 . A mixture of bases (1 g, 0.1% of the dry raw material mass) was obtained as usual from the acidic solution and was separated over a column of silica gel (KSK, 1:60) using gradient elution by hydrocarbons:EtOAc. The hydrocarbon:EtOAc effluents (1:4) afforded successively the known alkaloids skimmianine (1, 55 mg) [1b], J-fagarine (2, 17 mg) [1c], N-methyl-2-phenylquinolin-4-one (3, 23 mg) [1d]; the EtOAc ones, leptomerine (4, 15 mg) [1e], acutine (5, 12 mg) [1f], and 2-heptylquinolin-4-one (6, 13 mg).Alkaloids 1-5 were identified using TLC and mixed samples with authentic compounds that were obtained previously from this species (1-4) [1a] and Haplophyllum acutifolium (5) [1f].Compound 6 was identified from its PMR spectrum (400 MHz, CDCl 3 , G, ppm, J/Hz, 0 = HMDSO): 0.72 (3H, t, 3 J = 7.02, CH 3 ), 1.14 (8H, m, 4 u CH 2 ), 1.72 (2H, m, CH 2 ), 2.90 (2H, t, 3 J = 7.78, Ar-CH 2 ), 6.74 (1H, s, H-3), 7.43 and 7.64 (1H each, m, H-6, 7), 8.25 (1H, d, 3 J = 9.63, H-8), 8.33 (1H, dd, 3 J = 8.28, 4 J = 1.50, H-5), which indicated that 6 was 2-heptylquinolin-4-one, which was isolated previously from Pseudomonas microorganisms [3, 4] and synthesized from acutine [4]. Direct comparison of 6 with a synthetic sample (TLC, mixed sample) showed that they were identical.In addition to the aerial part, we collected roots of H. leptomerum, which had not been previously studied. The total alkaloid fraction from the roots (67 g) was obtained by the aforementioned method (0.17 g, 0.25% of dry raw material mass) and separated over a column of silica gel 60 (0.063-0.100 mm, Merck) at a mixture:adsorbent ratio of 1:100 using CHCl 3 elution. The known alkaloids dictamnine (7, 7 mg) [1g] and 2 (10 mg) were isolated successively from the effluents and were identified using TLC and PMR spectra. PMR spectrum of 2 (400 MHz, CDCl 3 , G, ppm, J/Hz, 0 = HMDSO): 4.02 (3H, s, OCH 3 ), 4.39 (3H, s, OCH 3 ), 6.88 (1H, dd, 3 J = 7.68, 4 J = 1.16, H-7), 7.02 (1H, d, 3 J = 2.84, H-3), 7.30 (1H, dd, 3 J 1 = 8.63, 3 J 2 = 7.68, H-6), 7.58 (1H, d, 3 J = 2.84, H-2), 7.78 (1H, dd, 3 J = 8.63, 4 J = 1.16, H-5). PMR spectrum of 7 (400 MHz, DMSO-d 6 , G, ppm, J/Hz, 0 = HMDSO): 4.41 (3H, s, CH 3 O-4), 7.45 (1H, d, 3 J = 3.75, H-3), 7.46 and 7.64 (1H each, ddd, 3 J 1 = 8.48, 3 J 2 = 6.74, 4 J = 1.50, H-6, 7), 7.84 (1H, dm, 3 J = 8.48, H-8), 8.01 (1H, d, 3 J = 3.75, H-2), 8.18 (1H, ddd, 3 J = 8.48, 4 J = 1.50, 5 J = 0.62, H-5).Thus, the aerial part of H. leptomerum afforded six (1-6) alkaloids; the roots, two (2, 7). Acutine (5), 2-heptylquinolin-4-one (6), and dictamnine (7) were observed for the first time in this plant.Herein we report also results from a study of the anticancer properties of...

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“…Compounds 3-5 were reduced with hydriodic acid [3] to give a compound with mp 66-68°C, UV spectrum (EtOH, λ max , nm) 272, 328, that was characterized as coumarin [4].…”

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“…Compound 3, yield 0.015%, mp 202-203°C (MeOH), TLC R f 0.55 (system I), 0.52 (system II), UV spectrum (EtOH, λ max , nm) 231, 295, 340, scopoletin [4].…”

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Biologically Active Substances from Cacalia hastata Leaves. 5. Coumarins and Triterpenes

Оленников

Танхаева

2005

Chem Nat Compd

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582.998+581.192 In continuation of research on the chemical composition of Cacalia hastata L. leaves, a batch (1.0 kg) was processed in a Soxhlet apparatus successively by C 6 H 14 , CHCl 3 , and EtOAc. After saponification (10% KOH/EtOH), the CHCl 3 extract was diluted in water (1:5). The resulting solid was filtered off and chromatographed over silica gel (CHCl 3 :EtOH, 100:0→90:10) with TLC monitoring (C 6 H 6 :MeOH, 4:1; C 6 H 14 :C 6 H 6 :CHCl 3 :MeOH, 5:4:2:1) to isolate two compounds 1 and 2.The aqueous phase after saponification was acidified and extracted with CHCl 3 . The extract was chromatographed over silica gel (CHCl 3 :EtOH, 100:0→95:5) with paper chromatographic (formamide:CHCl 3 , system I) and TLC (CHCl 3 :EtOH, 19:1, system II) monitoring. The isolated compounds were rechromatographed in a free layer of silica gel (40/100, system I) and recrystallized from MeOH to afford three compounds 3-5.Qualitative reactions established that 1 and 2 were triterpenes; 3-5, coumarins. The isolated compounds were identified using UV spectroscopy, chromatographic mobility, melting and mixed melting points, chemical transformations, and optical rotations.Compound 1, yield 0.05%, mp 139-140°C, [α] D 20 -36° (c 0.5, CHCl 3 ) [1], identified as β-sitosterol. Compound 2, oleanolic acid [2], yield 0.12%, pale yellow needlelike crystals, mp 308.0-309.8°C, [α] D 20 +78° (c 0.5, CHCl 3 ), UV spectrum (H 2 SO 4 , λ max , nm) 310 [1]. Acetylation of 2 produced the acetate with mp 257-258°C. Compounds 3-5 were reduced with hydriodic acid [3] to give a compound with mp 66-68°C, UV spectrum (EtOH, λ max , nm) 272, 328, that was characterized as coumarin [4]. Compound 3, yield 0.015%, mp 202-203°C (MeOH), TLC R f 0.55 (system I), 0.52 (system II), UV spectrum (EtOH, λ max , nm) 231, 295, 340, scopoletin [4].Compound 4, yield 0.009%, mp 230-232°C (EtOH), TLC R f 0.18 (system I), 0.041 (system II), UV spectrum (EtOH, λ max , nm) 228, 256, 330, umbelliferone [5]. The structure of 4 was confirmed by direct synthesis from malic acid and resorcinol by a Pechmann reaction [6].Compound 5, yield 0.001%, mp 269-270°C (EtOH), TLC R f 0.02 (system I), 0.15 (system II), UV spectrum (EtOH, λ max , nm) 262, 305, 356, esculetin [5].Coumarins in C. hastata leaves were determined quantitatively using chromatography and spectrophotometry and the specific extinction coefficients E (1 cm, 1%) [7]; triterpenes calculated for oleanolic acid, by spectrophotometry using a halochromic reaction with conc. H 2 SO 4 [8]. It was found that the contents of scopoletin, esculetin, and triterpenes in C. hastata leaves increased during mass flowering, reaching values of 0.031, 0.002, and 0.92%, respectively, and slightly decreased by autumn (Table 1). The exception was umbelliferone, the concentration of which increased toward the end of vegetation.Triterpenes in representatives of the genus Cacalia L. have been observed in C. aconitifolia (oleanolic acid acetate) [2] and C. kamtschatica (β-amurin, β-sitosterol, stigmasterol, campesterol) [9, 10]. Coumarin...

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Untitled

Cited by 9 publications

References 1 publication

Construction and optimization of a power complex with a distributed generation on the basis of renewables and methods of artificial intelligence (on the example of the Republic of Tajikistan)

Construction and optimization of a power complex with a distributed generation on the basis of renewables and methods of artificial intelligence (on the example of the Republic of Tajikistan)

Alkaloids from Haplophyllum leptomerum

Biologically Active Substances from Cacalia hastata Leaves. 5. Coumarins and Triterpenes

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