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KiMYA PROBLEMLORi № 2 2017
UDC 547.972 : 615.32:582.998.1
FUNDAMENTAL RESEARCH INTO CHEMICAL COMPONENTS
OF GEORGIAN FLORA
K.Shalashvili, T.Sagareishvili, N.Kavtaradze, M.Sutiashvili, M.Alania,
K.Kobakhidze, T.Gigoshvili
I.Kutateladze Institute of Pharmacochemistry, Tbilisi State Medical University 36, P.Sarajishvili st., Tbilisi, 0159, Georgia E-mail: kshalashvili@yahoo.com
Species of the families Scrophulariaceae, Leguminosae, Urticaceae, Asteraceae and Geraniaceae have been analyzed to identify contents of biologically active substances. Fifty-six phenol compounds have been isolated, and 14 ones found to be structurally new: Flagalosides A-D; Falcosides A-E; kaempferol-3-O-fi-D-di-galacto-xyloside; 6''"-O-[6-O-(4 "-trans-p-methoxy-cinnamoyl-5-hydroxi-aucubigenin-(1 —1 )-O-fi-D-galactopyranosyl]-6 " "-O-trans-p-methoxy-cinnamoyl-aucubin (laxoside); pelargonidin-3-O-gluco-di-galactoside; pelargonidin-3-O-[(^-vanillyl-xylopyranosyl]-%-O-xylopyranoside; pelargonidin-3-O-xylopyranoside; 1-O-galloyl-3,6-hexahydroxidiphenyl-fi-D-galactopyranoside (Pusilagin); Micranthoside (+) 2R:3R; Neomicranthoside (-) 2S:3S. Structures of isolated compounds were established on the basis of their physical, chemical and physical-chemical properties, by studying ofproducts of chemical transformation and by spectral (1H and 13C NMR, HSQC, HMBC, COSY, DEPT, mass-spectroscopy) data.
The new individual compounds displayed interesting biological effect to be promising from medical application standpoint.
Key words: flavonoids, falcosides, flagalosides, iridoids, laxoside
Species of Georgian flora have been notable for their healing properties since ancient times. At present, a special emphasis is laid on analysis of some species of Scrophulariaceae, Leguminosae, Urticaceae, Asteraceae and Geraniaceae families. Fifty six compounds were isolated by carrying out basic studies into chemical composition of the species. Fourteen compounds of them were structurally new: Flagalosides A-D; Falcosides A-E; kaempferol-3-O-P-D-di-galacto-xyloside; 6""-O-[6-O-(4"-trans-p-methoxy-cinnamoyl-5-hydroxi-
aucubigenin-(1—1')-O-P-D-galactopyranosyl]-6''''-O-trans-p-methoxy-cinnamoyl-aucubin (laxoside); pelargonidin-3-O-gluco-di-
galactoside; pelargonidin-3-O-[(^-vanillyl-xylopyranosyl]-^-O-xylopyranoside; pelargonidin-3-O-xylopyranoside; 1-O-galloyl-3,6-hexahydroxidiphenyl-P-D-galactopyranoside (Pusilagin); Micranthoside (+) 2R:3R; Neomicranthoside (-) 2S:3S. The last two ones are trans-type enantiomers of 7-O-methyl-aromadendrin-5-O-P-D-glucopyranoside [1-6]).
K. SHALASHVILI et al.
163
R-iO
H3CO.
OH O
OR O
Micranthoside
Falcoside C - R = [P-Glcp-(1-— 3)-a-Rhap-(1-^ 6)-p-Galp Ri= Glcp R2= OH
Falcoside D - R = [p-Xylp-(t*- 3)-Rhap-(1"^ 6)]-Galp Rl= Rhap R2 = OCH3
Flagaloside C - R= p-Galp-(6-^ 1)-a-Rhap-(2 1 )-Xylp Rl= H
r2= och3
Flagaloside D- R= p-Xylp-(2 1)-p-Xylp Pusilaside - R= p-Galp-^-p-Galp-^-p-Xylp
R1= R2= H
H3CO
JXh
ORi O
Neomicranthoside
R = R1 = p-D-Glc
R
2
Compounds were isolated from dried and crushed raw material through the extraction of 80 % ethanol. The aqueous residue after evaporation was purified with chloroform to get rid of lipophyllic compounds. In some cases, the individual substances were crystallized from the purified aqueous liquid. Micranthoside and Neomicranthoside were isolated in the same manner out of flower extract of Eupatorium Micranthum. After separation of the crystals, an aqueous part was extracted with ethyl acetate. Fractions of phenolic compounds were obtained by evaporating the extragent until a dry residue was obtained. The separation of individual compounds from ethyl acetatic and aqueous fractions were carried out by using silica gel (Kiselgel-60), diaion resin, polyamide and Sephadex LH-20.
Structures of isolated compounds were established on the basis of their physical, chemical and physical-chemical properties, by studying of products of chemical transformation and by spectral (1H and 13C NMR, HSQC, HMBC, COSY, DEPT, mass-spectroscopy) data.
The structure elucidation of the new iridoid glycoside from Verbascum laxum is given below. Iridoid glycoside (1) was obtained as light brown crystalls, m.p. 110-114 °C, IR-spectrum (KBr, Vmax, cm-1): 3600, 3430 (-OH), 1710, 1708 (c=O), 1645 (C=C), 1604, 1546, 1360 (Ar); UV spectrum (^max, nm): 206, 218 sh, 225 sh, 290; Mass-spectrum, m/z (I, %): 1011 [M=H]+ (0.8); MS/MS: m/z 691 [m+H-320]+ (0.9) (two molecules of trans-p-methoxy-cinnamic acid), 529 [M+H-320-162]+ (15), 351 [M+H-320-162-178]+ (65).
The molecular ion peak with m/z 1010 [M+H]+. It corresponded to the formule C50H58O22. The absorbtion peaks characterising to the enol-ester system of iridoid and aromatic acids at 206, 218 (sh), 225 (sh), 290 nm were visible in the UV-spectrum. The complete assignment of 1H and 13C NMR signals (Tabe 1) and their comparison to the 2D NMR-experiments showed the presence of two iridoid aglycon fragments of trans-p-methoxy-cinnamoyl acid. Signals of two anomeric protons at SH 5.08 (d, J=7.8 Hz) and SH 4.71 (d, J=7.8 Hz), the signals of two couple of methylene at 6"" and 6' (SH 3.71, 3.68; SH 3.88, 3.68) also the resonance signals of eight
protons at Sh 3.96 and 3.42 (H-2, 3, 4, 5) indicated the presence of two molecules of carbohydrates. Downfield shift signals of 6' and 6'''' atoms of carbohydrate units suggested the fact of their substitution. The structure of two molecules of trans-p-methoxycinnamic acid was established by 1H NMR spectra where there became visible neighboring olefinic protons at SH 6.46 and 7.70 (Jax=15.91 Hz), Sh 6.45 and 7.62; four signals of aromatic protons Sh 6.99 (2H), 7.60 (2H), 6.81 (2H), 7.30 (2H) and, finally, two signals of methoxyl groups at SH 3.86 and 3.83. Signals at 55.6 and 55.9 ppm in the 13C NMR spectrum reaffirmed the presence of methoxyl groups.
One of the two fragments of irodoid glycoside 1 showed characteristic signals SH 6.38 (d, J=6.5 Hz, H-3) and Sh 5.16 (d, J=6.5 Hz, H-4), 5.93 (br. s., H-7) of two ortho- and one olefinic proton in 1H NMR spectrum. Also, proton signals at SH 4.96 (d, J=4.2 Hz, H-1), 4.52 (br. s., H-6) indicated the substitution at position 1 and 6. Six signals of tertiary carbon at S 97.9 (C-1), 140.5 (C-3), 103.9 (C-4), 87.9 (C-6), 125.4 (C-7), 46.7 (C-9) and one signal of secondary carbon at S 60.7 (C-10) respectively became apparent in the DEPT. A signal of quaternary carbon at SC71.9 showed the presence of hydroxyl group in the position C-5
[7]. Acylation at C-6 position was confirmed by the downfield chemical sift (SH4.52) of H-6 proton. Proceeding from the NMR spectral data and literature sources, iridoid was specified as 5-hydroxyaucubigenin [8, 9].
Chemical shifts of the second part of molecule slightly differed from the first one (Table 1); there was just a single difference: presence of H-5'''proton signal at SH 2.80.
Interconnection between the identified structures (2 molecules of iridoid, trans-p-methoxycinnamic acid and carbohydrate) was established by HMBC experiment. Correlations were clearly displayed between SH4.52 (H-6) and Sc 168.7 (C-10''); Sh4.71 (Gal H-1') and Sc 97.9 (C-1); Sh4.96 (H-1) and Sc 98.5 (C-1'); Sh4.50 (H-6''') and Sc 62.7 (C-6'); Sh4.99 (H-1''') and Sc 100.0 (C-1''''); Sh3.68 (H-6'''') and Sc 172.2 (C-10''''').
It should be noted that the spectral data were corroborated by the results of chemical transformation. Acyd hydrolysis of 1 gave D-galactose, D-glucose, as well as a product with typical reaction for iridoids . Trans-p- methoxy-cinnamic acid and less polar glycoside were formed by alkaline hydrolysis of 1. Acid hydrolysis of less polar glycoside provided D-Glucose and D-Galactose.
OCH3
Laxoside
K.SHALASHVILI
165
Based on the results of spectral analysis and chemical transformation. Comparison of the literature data with the structure 1 made it possible to identify 6 ' ' ' '-O-[6-O-(4 ' '-trans-p-methoxy-cinnamoyl-5-hydroxi-aucubigenin-
(1 —>1' )-O-P-D-galactopyranosyl]-6 ' ' ' '-O-trans-p-methoxy-cinnamoyl-aucubin. The substance with the identical structure has not been described in literature: the point is about a new compound termed as laxoside.
Table 1. 1H and 13C NMR spectral data of 1 (500 MHz, CD3OD, Ô, ppm, J/Hz)
C ÔC ÔH C ÔC ÔH Aucubigenin
1 97.9 4.96 (d, J=4.2) 1' ' ' 98.5 4.99 (d, J=6.0) 4.82 (d, J= 1.9)
3 140.5 6.38 (d, J=6.5) 3' ' ' 143.9 6.44 (d, J=5.6) 5.84 br.s.
4 103.9 5. 16 (d, J=6.5) 4 ' ' ' 106.9 5. 17 (d, J=5.6) 4.92 (dd,
J=6.0; 3.5)
5 71.9 - 5' ' ' 46.2 2.80 m 2.50 m
6 87.9 4.52 br.s. 6 ' ' ' 89.4 4.50 m 4.70 m
7 125.4 5.93 br.s. 7 ' ' ' 126.2 5.90 br.s. 5.84 br.s.
8 148.5 - 8 ' ' ' 149.9 - -
9 46.7 2.96 (d, J=4.2) 9 ' ' ' 47.2 2.98 (dd, J=6.0; 7.2) 2.80 m
10 a 60.7 4.22 (d, J=14.0) 10'' 'a 61.0 4.25 (d, J=14.4) 4.25 br.s.
10 b 4.40 (d, J=14.0) 10 ' ' 'b 4.47 (d, J=14.4)
1' 98.5 4.71 (d, J=7.8) 1' ' ' ' 100.0 5.08 (d, J=7.8)
2 ' 73.3 3.62 (dd, J=9.8; 7.8) 2 ' ' ' ' 74.5 3.68 (dd, J=9.0; 7.8)
3' 76.2 3.42 (dd, J=9.8; 3.4) 3' ' ' ' 77.7 3.48 (dd, J=9.0; 9.0)
4 ' 70.1 3.90 (dd, J=3.4; 1.1) 4 ' ' ' ' 71.7 3.96 (dd, J=9.0; 9.0)
5' 76.7 3.50 m 5' ' ' ' 77.7 3.48 m
6 ' a 62.7 3.68 (dd, J=11.8; 5.9) 6 ' ' ' ' a 63.0 3.68 (dd, J=12.0; 4.5)
P 3.88 (dd, J=11.8; 7.0) P 3.71 (dd, J=12.0; 2.0)
1' ' 127.6 - 1 ' ' ' ' ' 129.2 -
2 ' ' 130.0 7.60 (d, J=8.4) 2 ' ' ' ' ' 131.5 7.30 (d, J=8.4)
3' ' 114.0 6.99 (d, J=8.4) 3 ' ' ' ' ' 115.5 6.81 (d, J=8.4)
4 ' ' 162.0 - 4 ' ' ' ' ' 163.4 -
5' ' 130.0 6.99 (d, J=8.4) 5 ' ' ' ' ' 115.5 6.81 (d, J=8.4)
6 ' ' 113.9 7.60 (d, J=8.4) 6 ' ' ' ' ' 131.3 7.30 (d, J=8.4)
8 ' 'a 145.6 6.46 (d, J=16.0) 8 ' ' ' ' ' 115.0 6.45 (d, J=16.0)
9' 'P 7.70 (d, J=16.0) 9 ' ' ' ' ' 146.1 7.62 (d, J=16.0)
10 ' ' 168.7 - 10 ' ' ' ' ' 172.2 -
7 ' '- 55.9 3.83 s 7'' '''-OCH3 55.6 3.86 s
OCH3
The new individual compounds from medical point of view.
displayed interesting biological activities to be promising REFERENCES
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7. Jinfeng Tian, Xiaoli Ye, Yuanhong Shang, Yafei Deng, Kai He, Xuegang Li. Preparative isolation and purification of harpagoside and angroside C from the root of Scrophularia ningpoensis Helmsei by high-speed counter-current chromatography. J. Sep. Sci., 2012, vol.35, issue 19, pp.26592664.
8. I. Irem Tatli, Ikhlas A. Khan, Zeliha S. Akdemir. Acilated iridoid glycosides from the flowers of Verbascum lasianthum Boiss. ex Bentham, Z. Naturforsch., 2006, vol. 61b, issue 9, pp. 1183-1187.
9. Ulrike W. Arnold, Christian Zidorn, Ernst P. Ellmerer, Hermann Stuppner. Iridoid and phenolic glycosides from Wulfenia carinthiaca. Z. Naturforsch, 2002, vol. 57, Issue 11-12, pp. 969-975.
ФУНДАМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ ХИМИЧЕСКИХ КОМПОНЕНТОВ
РАСТИТЕЛЬНОСТИ ГРУЗИИ
К.Г.Шалашвили, Т.Г.Сагареишвили, Н.Ш.Кавтарадзе, М.Г.Сутиашвили, М.Д.Алания, К.Б.Кобахидзе, Т.И.Гигошвили
Институт фармакохимии им. И.Г.Кутателадзе Тбилисского Государственного медицинского
университета
Тбилиси, ул.Сараджишвили,36 ; e-mail: kshalashvili@yahoo.com
Виды семейств Scrophulariaceae, Leguminosae, Urticaceae, Asteraceae, Geraniaceae были исследованы на содержание биологически активных веществ. Из изученных объектов выделены и охарактеризованы 56 фенольных соединений; 14 из них оказались структурно новыми: флагалозиды A-D; фалкозиды A-E; кемпферол-З-й-в-Б-ди-галакто-ксилозид; 6""-O-[6-O-(4 "-trans-p-метокси-циннамоил-5-гидрокси-аукубигенин-(1 —1 /)-O-в-D-галактопиранозил]-6////-O-trans-п-метокси-циннамоил-аукубин (лаксозид); пеларгонидин-3-O-глюко-ди-галактозид; пеларгонидин-3-O-tf^-ванилил-ксилопиранозил]-%-O-ксилопиранозид; пеларгонидин-3-O-ксилопиранозид; l-O-галлоил-Зб-гексагидроксидифенил-в-Б-галактопиранозид (пусилагин); микрантозид (+) 2R:3R; неомикран-тозид (-) 2S:3S. Структуры выделенных веществ установлены на основании их физико-химических свойств, изучением продуктов химического превращения и данными спектров ИК, УФ, 1Н и 13С ЯМР, масс, а также методами корреляционной спектроскопии HSQC, HMBC, DEPT, COSY. Ключевые слова: флавоноиды, фалкозиды, флагалозиды, иридоиды, лаксозид.
Поступила в редакцию 19.11.2016.
