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1.
A new abscisic acid derivative, named litseaglutinan A ( 1 ), and a new arylnaphthalene‐type lignan, (7′S,8R,8′S)‐4,4′,9‐trihydroxy‐3,3′,5‐trimethoxy‐9′‐O‐β‐D ‐xylopyranosyl‐2,7′‐cyclolignan ( 2 ), were isolated from the AcOEt extract of Litsea glutinosa, together with nine known lignans. Their structures were established by spectroscopic methods. 相似文献
2.
Naveen Mukhtar Abdul Malik Naheed Riaz Kiran Iqbal RasoolBakhsh Tareen ShamsunNahar Khan SarfrazAhmad Nawaz Juveria Siddiqui M.Iqbal Choudhary 《Helvetica chimica acta》2004,87(2):416-424
Pakistolides A and B, novel dimeric β‐(glucosyloxy)benzoates were isolated from Berchemia pakistanica and assigned structures 1 and 2 on the basis of extensive NMR studies. In addition, the known compounds 7,5′‐dimethoxy‐3,5,2′‐trihydroxyflavone (=3,5‐dihydroxy‐2‐(2‐hydroxy‐5‐methoxyphenyl)‐7‐methoxy‐4H‐1‐benzopyran‐4‐one), 4′,5‐dihydroxy‐3,6,7‐trimethoxyflavone (=5‐hydroxy‐2‐(4‐hydroxyphenyl)‐3,6,7‐trimethoxy‐4H‐1‐benzopyran‐4‐one), 5,6‐dihydroxy‐4,7‐dimethoxy‐2‐methylanthracene‐9,10‐dione, and 1,3,4‐trihydroxy‐6,7,8‐trimethoxy‐2‐methylanthracene‐9,10‐dione were reported for the first time from the genus Berchemia. Both 1 and 2 showed significant α‐glucosidase and lipoxygenase inhibitory activities, while 2 also showed antioxidant potential. 相似文献
3.
Ericsson D. Coy‐Barrera Luis E. Cuca‐Surez Michael Sefkow Uwe Schilde 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(8):o320-o322
The structure of naturally‐occurring cinerin C [systematic name: (7S,8R,3′R,4′S,5′R)‐Δ8′‐4′‐hydroxy‐5,5′,3′‐trimethoxy‐3,4‐methylenedioxy‐2′,3′,4′,5′‐tetrahydro‐2′‐oxo‐7.3′,8.5′‐neolignan], isolated from the ethanol extract of leaves of Pleurothyrium cinereum (Lauraceae), has previously been established by NMR and HRMS spectroscopy, and its absolute configuration established by circular dichroism measurements. For the first time, its crystal strucure has now been established by single‐crystal X‐ray analysis, as the monohydrate, C22H26O7·H2O. The bicyclooctane moiety comprises fused cyclopentane and cyclohexenone rings which are almost coplanar. An intermolecular O—H...O hydrogen bond links the 4′‐OH and 5′‐OCH3 groups along the c axis. 相似文献
4.
Two new flavones, 8‐hydroxy‐7,3′,4′,5′‐tetramethoxyflavone and 8,4′‐dihydroxy‐7,3′,5′‐trimethoxyflavone, together with thirteen known compounds have been isolated from the stem bark of Muntingia calabura. The structures of two new compounds were determined through spectral analyses. Among the isolates, 8‐hydroxy‐7,3′,4′,5′‐tetramethoxyflavone, 8,4′‐dihydroxy‐7,3′,5′‐trimethoxyflavone, and 3‐hydroxy‐1‐(3,5‐dimethoxy‐4‐hydroxyphenyl)propan‐1‐one exhibited effective cytotoxicities (ED50 values = 3.56, 3.71, and 3.27 μg/mL, respectively) against the P‐388 cell line in vitro. 相似文献
5.
A new isoflavone together with 5,7-dimethoxy-3,4′-dihydroxy-3′,8-di-C-prenylflavanonol and 5,3′-dihydroxy-6,7,4′-trimethoxyflavone has been isolated from the arial parts of Phylanthus niruri. Based on spectral methods, the structure of the new compound was elucidated as 6-hydroxy-7,8,2′,3′,4′-pentamethoxyisoflavone. The isolated isoflavone was quantified by gas chromatography couple with mass spectroscopy (GC–MS) in selected ion monitoring (SIM) mode. Suitable methods for quantification and extraction have been developed. The quantifying limit of this method was less than 5 ng/ml in 10 g (fresh weight) of sample. Recovery of isoflavone in spiked samples exceeded 62–72% while R.S.D. ranged from 1.0% to 6.1%. The results showed significant variation in the amount of this marker in methanol extract of Phylanthus niruri from Kushtia, Bangladesh and Java Island, Indonesia, even though the values were almost identical for most of the cases. Isoflavone was detected in all the samples ranging from 0.12% to 0.29%. 相似文献
6.
Separation and purification of 9,10‐dihydrophenanthrenes and bibenzyls from Pholidota chinensis by high‐speed countercurrent chromatography 下载免费PDF全文
Yang Chen Shining Cai Liang Deng Qiang Xia Lian‐Feng Du Guo‐Zhen Cui Jun Li Xu‐Mei Zhou Qizhang Ye Yan Zhou Mao Lin 《Journal of separation science》2015,38(3):453-459
Stilbenoids are the main components of leaves and stems of Pholidota chinensis. In the present investigation, high‐speed counter‐current chromatography was used for the separation and purification of two classes of stilbenoids, namely, bibenzyls and 9,10‐dihydrophenanthrenes, on a preparative scale from whole plants of P. chinensis with different solvent systems after silica gel column chromatography fractionation. n‐Hexane/ethyl acetate/methanol/water (1.2:1:1:0.8, v/v/v/v) was selected as the optimum solvent system to purify 1‐(3,4,5‐trimethoxyphenyl)‐1′,2′‐ethanediol ( 1 ), coelonin ( 2 ), 3,4′‐dihydroxy‐5,5′‐dimethoxybibenzyl ( 3 ), and 2,?7‐?dihydroxy‐?3,?4,?6‐?trimethoxy‐?9,?10‐?dihydrophenanthrene ( 4 ). While 2,7‐dihydroxy‐3,4,6‐trimethoxy‐?9,?10‐?dihydrophenanthrene ( 5 ), batatasin III ( 6 ), orchinol ( 7 ), and 3′‐O‐methylbatatasin III ( 8 ) were purified by n‐hexane/ethyl acetate/methanol/water (1.6:0.8:1.2:0.4, v/v/v/v). After the high‐speed counter‐current chromatography isolation procedure, the purity of all compounds was over 94% assayed by ultra high performance liquid chromatography. The chemical structure identification of all compounds was carried out by mass spectrometry and 1H and 13C NMR spectroscopy. To the best of our knowledge, the current investigation is the first study for the separation and purification of bibenzyls and 9,10‐dihydrophenanthrenes by high‐speed counter‐current chromatography from natural resources. 相似文献
7.
Zun‐Ting Zhang Yan‐Chang Wang 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(1):o51-o53
In the lattice of the title compound (systematic name: 5,6,7‐trihydroxy‐4′‐methoxyisoflavone monohydrate), C16H12O6·H2O, the isoflavone molecules are linked into chains through R43(17) motifs composed via O—H⋯O and C—H⋯O hydrogen bonds. Centrosymmetric R42(14) motifs assemble the chains into sheets. Hydrogen‐bonding and aromatic π–π stacking interactions lead to the formation of a three‐dimensional network structure. 相似文献
8.
Two new diarylheptanoids, katsumains A ( 1 ) and B ( 2 ), and one new kavalactone, katsumadain ( 3 ), together with the three known compounds (4E,6E)‐1,7‐diphenylhepta‐4,6‐dien‐3‐one ( 4 ), (5R,6E)‐1,7‐diphenyl‐5‐hydroxyhept‐6‐en‐3‐one ( 5 ), and cardamonin ( 6 ), were isolated from the seeds of Alpinia katsumadai Hayata . Their structures were elucidated mainly by spectroscopic methods (1D‐ and 2D‐NMR) and by mass spectrometry (HR‐ESI‐MS). Besides, the erroneous nomenclatures for (+)‐linderatin and (+)‐neolinderatin as given in [10] [11] were corrected to be 2′,4′,6′‐trihydroxy‐3′‐[(3R,4R)‐4‐isopropyl‐1‐methylcyclohex‐1‐en‐3‐yl]dihydrochalcone for (+)‐linderatin and 2′,4′,6′‐trihydroxy‐3′,5′‐bis[(3R,4R)‐4‐isopropyl‐1‐methylcyclohex‐1‐en‐3‐yl]dihydrochalcone for (+)‐neolinderatin, respectively. 相似文献
9.
Direct electrochemistry of cholesterol oxidase (ChOx) immobilized on the conductive poly‐3′,4′‐diamine‐2,2′,5′,2″‐terthiophene (PDATT) was achieved and used to create a cholesterol biosensor. A well‐defined redox peak was observed, corresponding to the direct electron transfer of the FAD/FADH2 of ChOx, and the rate constant (ks) was determined to be 0.75 s?1. Glutathione (GSH) covalently bonded with PDATT was used as a matrix for conjugating AuNPs, ChOx, and MP, simultaneously. MP co‐immobilized with ChOx on the AuNPs‐GSH/PDATT exhibited an excellent amperometric response to cholesterol. The dynamic range was from 10 to 130 μM with a detection limit of 0.3±0.04 μM. 相似文献
10.
Jzsef Deli Pter Molnr Zoltn Matus Gyula Tth Andrea Steck 《Helvetica chimica acta》1996,79(5):1435-1443
Cucurbitaxanthin A (= (3S,5R,6R,3′R)-3,6-epoxy-5,6-dihydro-β,β- carotene-5,3′-diol; 5 ), cucurbitaxanthin B (= (3S,5R,6R,3′S,5′R,6′S)-3,6,5′, 6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol; 6 ), the epimeric cucurbitachromes 1 and 2 (= (3S,5R,6R,3′S,5′R,8′S)- and (3S,5R,6R,3′S,5′R,8′R)-3,6,5′, 8′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol, resp.; 9/10 ), cycloviolaxanthin (= (3S,5R,6R,3′S,5′R,6′R)-3,6,3′, 6′-diepoxy-5,6,5′,6′-tetrahydro-β,κs-carotene-5,5′-diol; 8 ), and capsanthin 3,6-epoxide (= (3S,5R,6R,3′S,5′R)-3,6-epoxy-5,6-dihydro ?5,3′-dihydroxy-β,κ-caroten-6′-one; 7 ) were isolated from red spice paprika (Capsicum annuum var. longum) and characterized by their 1H- and 13C-NMR, mass, and CD spectra. 相似文献
11.
Jzsef Deli Zoltn Matus Pter Molnr Gyula Tth Zoltn Dcsy Conrad Hans Eugster 《Helvetica chimica acta》1993,76(2):952-956
Epoxidation of Cucurbitaxanthin A: Preparation of Cucurbitaxanthin B and of Its 5′,6′-Epimer Cucurbitaxanthin A (= (3S,5R,6R,3′S)-3,6-epoxy-5,6-dihydro-β,β-carotene-5,3′-diol; 1 ) isolated from red pepper (Capsicum annuum var. longum nigrum) was trimethylsiylated and then epoxidized with monoperphthalic acid. After deprotection and chromatographic separation, cucurbitaxanthin B (= (3S,5R,6R, 3′S,5′R,6′S)-3,6:5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol; 2 ) and 5′,6′-diepicucurbitaxanthin B (= (3S,5R,6R, 3′S,5′S,6′R)-3,6:5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol; 5 ) were obtained and carefully characterized. They show mirror-like CD spectra and, therefore, emphasize the importance of the torsion angle of C(6)–C(7) on the electronic interaction between the polyene chain and the chiral end group. 相似文献
12.
Rohitesh Kumar Yuting Lu Alysha G. Elliott Angela M. Kavanagh Matthew A. Cooper Rohan A. Davis 《Magnetic resonance in chemistry : MRC》2016,54(11):880-886
Previous investigations of the aerial parts of the Australian plant Eremophila microtheca and Syzygium tierneyanum resulted in the isolation of the antimicrobial flavonoid jaceosidin ( 4 ) and 2′,6′‐dihydroxy‐4′‐methoxy‐3′,5′‐dimethyl chalcone ( 7 ), respectively. In this current study, compounds 4 and 7 were derivatized by acetylation, pivaloylation, and methylation reactions. The final products, 5,7,4′‐triacetoxy jaceosidin ( 10 ), 5,7,4′‐tripivaloyloxy jaceosidin ( 11 ), 5,7,4′‐trimethoxy jaceosidin ( 12 ), 2′,6′‐diacetoxy‐4′‐methoxy‐3′,5′‐dimethyl chalcone ( 13 ), 2′‐hydroxy‐4′‐methoxy‐6′‐pivaloyloxy‐3′,5′‐dimethyl chalcone ( 14 ), and 2′‐hydroxy‐4′,6′‐dimethoxy‐3′,5′‐dimethyl chalcone ( 15 ) were all fully characterized by NMR and MS. Derivatives 10 and 13 have been previously reported but were only partially characterized. This is the first reported synthesis of 11 and 14 . The natural products and their derivatives were evaluated for their antibacterial and antifungal properties, and the natural product, jaceosidin ( 4 ) and the acetylated derivative, 5,7,4′‐triacetoxy jaceosidin ( 10 ), showed modest antibacterial activity (32–128 µg/ml) against Staphylococcus aureus strains. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
13.
Yi‐Huang Lu Chun‐Nan Lin Horng‐Huey Ko Sheng‐Zehn Yang Lo‐Ti Tsao Jih‐Pyang Wang 《Helvetica chimica acta》2002,85(6):1626-1632
With the scope of our search for biologically active compounds, two new phenolic compounds, artocarpols G ( 1 ) and H ( 2 ), and two known compounds, rubraflavone C ( 3 ) and trans‐stilbene‐2,4,3′,5′‐tetrol, were isolated from the root bark of Artocarpus rigida. Their structures were determined by spectroscopic methods and comparison with data reported in the literature. Compound 4 , previously isolated from this plant, strongly inhibited in a concentration‐dependent manner the release of β‐glucuronidase and histamine from mast cell degranulation caused by compound 48/80, with IC50 values of 10.9±1.4 and 13.2±0.6 μM , respectively. Compound 4 also showed a concentration‐dependent inhibitory effect on the formyl‐peptide‐stimulated superoxide anion formation in neutrophils with an IC50 value of 26.0±5.6 μM . 相似文献
14.
Pablo Romo Jairo Quiroga Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(8):779-785
The synthesis and characterization of three new dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine] compounds are reported, together with the crystal structures of two of them. (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐Chlorophenyl)‐1‐hexyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C28H30ClN3O2S2, (I), (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐1‐benzyl‐5‐methyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C30H26ClN3O2S2, (II), and (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐5‐fluoro‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C22H17ClFN3O2S2, (III), were each isolated as a single regioisomer using a one‐pot reaction involving l ‐proline, a substituted isatin and (Z)‐5‐(4‐chlorobenzylidene)‐2‐sulfanylidenethiazolidin‐4‐one [5‐(4‐chlorobenzylidene)rhodanine]. The compositions of (I)–(III) were established by elemental analysis, complemented by high‐resolution mass spectrometry in the case of (I); their constitutions, including the definition of the regiochemistry, were established using NMR spectroscopy, and the relative configurations at the four stereogenic centres were established using single‐crystal X‐ray structure analysis. A possible reaction mechanism for the formation of (I)–(III) is proposed, based on the detailed stereochemistry. The molecules of (I) are linked into simple chains by a single N—H…N hydrogen bond, those of (II) are linked into a chain of rings by a combination of N—H…O and C—H…S=C hydrogen bonds, and those of (III) are linked into sheets by a combination of N—H…N and N—H…S=C hydrogen bonds. 相似文献
15.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(12):1109-1115
Two spiro[indoline‐3,3′‐pyrrolizine] derivatives have been synthesized in good yield with high regio‐ and stereospecificity using one‐pot reactions between readily available starting materials, namely l ‐proline, substituted 1H‐indole‐2,3‐diones and electron‐deficient alkenes. The products have been fully characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry and crystal structure analysis. In (1′RS ,2′RS ,3SR ,7a′SR )‐2′‐benzoyl‐1‐hexyl‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine]‐1′‐carboxylic acid, C28H32N2O4, (I), the unsubstituted pyrrole ring and the reduced spiro‐fused pyrrole ring adopt half‐chair and envelope conformations, respectively, while in (1′RS ,2′RS ,3SR ,7a′SR )‐1′,2′‐bis(4‐chlorobenzoyl)‐5,7‐dichloro‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine], which crystallizes as a partial dichloromethane solvate, C28H20Cl4N2O3·0.981CH2Cl2, (II), where the solvent component is disordered over three sets of atomic sites, these two rings adopt envelope and half‐chair conformations, respectively. Molecules of (I) are linked by an O—H…·O hydrogen bond to form cyclic R 66(48) hexamers of (S 6) symmetry, which are further linked by two C—H…O hydrogen bonds to form a three‐dimensional framework structure. In compound (II), inversion‐related pairs of N—H…O hydrogen bonds link the spiro[indoline‐3,3′‐pyrrolizine] molecules into simple R 22(8) dimers. 相似文献
16.
Hyun Ji Shin Joo‐Won Nam Ui Joong Yoon Ah‐Reum Han Eun‐Kyoung Seo 《Helvetica chimica acta》2012,95(2):240-245
Three new flavonoids, 5,6,7,8,3′,4′‐hexamethoxyhomoflavone ( 1 ), 5,6,7,8,4′‐pentamethoxyhomoflavone ( 2 ) and 3,6,7,8,2′,5′‐hexamethoxyflavone ( 3 ) were isolated from the peels of mature fruits of Citrus unshiu Marcow (Rutaceae), together with the three known compounds 6,7,8,4′‐tetramethoxyflavone (=6,7,8‐trimethoxy‐2‐(4‐methoxyphenyl)‐4H‐1‐benzopyran‐4‐one), 3,5,7,8,2′,5′‐hexamethoxyflavone (=2‐(2,5‐dimethoxyphenyl)‐3,5,7,8‐tetramethoxy‐4H‐1‐benzopyran‐4‐one), and scopoletin (=7‐hydroxy‐6‐methoxy‐2H‐1‐benzopyran‐2‐one) of which the former two have never been isolated from natural resources, although they have been reported as synthetic compounds. The structures of 1 – 3 were elucidated on the basis of spectroscopic evidence, including 1D‐ and 2D‐NMR analysis. 相似文献
17.
Two stereoisomeric pentacyclic oxindole alkaloids from Uncaria tomentosa: uncarine C and uncarine E
Ilias Muhammad Ikhlas A. Khan Nikolaus H. Fischer Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):480-482
The chloroform solvate of uncarine C (pteropodine), (1′S,3R,4′aS,5′aS,10′aS)‐1,2,5′,5′a,7′,8′,10′,10′a‐octahydro‐1′‐methyl‐2‐oxospiro[3H‐indole‐3,6′(4′aH)‐[1H]pyrano[3,4‐f]indolizine]‐4′‐carboxylic acid methyl ester, C21H24N2O4·CHCl3, has an absolute configuration with the spiro C atom in the R configuration. Its epimer at the spiro C atom, uncarine E (isopteropodine), (1′S,3S,4′aS,5′aS,10′aS)‐1,2,5′,5′a,7′,8′,10′,10′a‐octahydro‐1′‐methyl‐2‐oxospiro[3H‐indole‐3,6′(4′aH)‐[1H]pyrano[3,4‐f]indolizine]‐4′‐carboxylic acid methyl ester, C21H24N2O4, has Z′ = 3, with no solvent. Both form intermolecular hydrogen bonds involving only the oxindole, with N?O distances in the range 2.759 (4)–2.894 (5) Å. 相似文献
18.
New flavone and isoflavone glycoside from Belamcanda chinensis 总被引:2,自引:0,他引:2
Li Jin Hai Sheng Chen Zhao Bao Xiang Shuang Liang Yong Sheng Jin Jian Guo Liu College of Pharmacy Second Military Medical University Shanghai China College of Bio-information Chongqing University of Posts Telecommunications Chongqing China 《中国化学快报》2007,18(2):158-160
The new flavone, 5,4'-dihydroxy-6,7-methylenedioxy-3'-methoxyflavone, and one new isoflavone glycoside, 3',5'-dimethoxy irisolone-4'-O-β-D-glucoside were isolated from the rhizomes of Belamcanda chinensis. Their structures were established based on the spectroscopic methods. 相似文献
19.
A new flavanone, euchrenone a17 ( 1 ), along with eighteen known compounds, glabrol ( 2 ), euchrenone a2 ( 3 ), formononetin ( 4 ), 7‐methoxy‐2′,4′‐dihydroxyisoflavone ( 5 ), 3‐(3,4‐dimethoxy‐phenyl)‐7,8‐dihydroxy‐chromon‐4‐one ( 6 ), 5,7,2′‐trihydroxy‐4′‐methoxyisoflavone ( 7 ), 2′‐hydroxygenistein ( 8 ), euchrenone b1 ( 9 ), euchrenone b2 ( 10 ), euchrenone b16 ( 11 ), vanillin ( 12 ), p‐hydroxybenzoic acid ( 13 ), medicagol ( 14 ), octadecyl ferulate ( 15 ), (+)‐syringaresinol ( 16 ), β‐sitosteryl‐D‐glucoside ( 17 ), and a mixture of β‐sitosterol ( 18 ) and stigmasterol ( 19 ), were isolated from the methanolic extracts of the roots of Euchresta formosana. The structures of these compounds were established by means of spectral analysis. 相似文献
20.
A chiral carthamin model (3S,3′S)‐1‐[5‐acetyl‐2,6‐diketo‐3‐C‐β‐d ‐glucopyranosylcyclohex‐4‐enylidene]‐1′‐[5′‐acetyl‐3′‐C‐β‐d ‐glucopyranosyl‐2′,3′,4′‐trihydroxy‐6′‐oxocyclohexa‐1′,4′‐dienyl]methane, in which two cinnamoyl groups were replaced by an acetyl group, was synthesized by the dimerization of (S)‐2‐acetyl‐4‐C‐(per‐O‐acetyl‐β‐d ‐glucopyranosyl)cyclohexadienone with glyoxylic acid, followed by peroxidase‐catalyzed oxidative decarboxylation and de‐O‐acetylation, or de‐O‐acetylation and peroxidase‐catalyzed oxidative decarboxylation. The corresponding total yields were 12.5% or 17.1% from 3‐C‐(per‐O‐acetyl‐β‐d ‐glucopyranosyl)phloroacetophenone, and the reaction pathway was identical to the biosynthetic pathway. 相似文献