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Article

Identification of Three Dalbergia Species Based on Differences in Extractive Components

1
Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China
2
Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China
3
Department of Chemistry, Tsinghua University, Beijing 100084, China
*
Author to whom correspondence should be addressed.
Molecules 2018, 23(9), 2163; https://doi.org/10.3390/molecules23092163
Submission received: 3 August 2018 / Revised: 23 August 2018 / Accepted: 24 August 2018 / Published: 28 August 2018

Abstract

:
Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon are precious and valuable traded timber species of the genus Dalbergia. For chemotaxonomical discrimination between these easily confused species, the total extractive content of the three wood species was determined using four different organic solvents. Fourier transform infrared (FTIR) spectroscopy was used to analyze functional group differences in the extractive components, inferring the types of principal chemical components according to characteristic peak positions, intensities, and shapes. Gas chromatography-mass spectrometry (GC-MS) was carried out a detailed characterization of the extractive components. The relative content of individual chemical components was determined by area normalization. Results revealed differences in the chemical components and total and individual extract contents of the three Dalbergia species, indicating that FTIR and GC-MS spectroscopy can be applied to identify and discriminate between Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon.

1. Introduction

Wood extractives are non-structural wood molecules that represent a minor fraction in wood, specifically defined as compounds that can be extracted by polar, non-polar, or neutral solvents [1,2]. Wood extractives account for approximately 2% to 5% of wood content, however, relatively high amounts of extractives can be found in some tropical woods, especially chemical extractives that are highly concentrated in heartwood [3,4,5]. Studies have demonstrated that many extractive components exhibit various biological activities and are important in medical applications [6,7]. Wood extractives include an array of compounds, usually aliphatic, terpenoid and phenolic in nature. According to the literature [8], Dalbergia spp. are rich in aromatic compounds, however, significant differences have been found in the types and contents of wood extractives, even within the same genus [3].
Dalbergia is a genus of trees belonging to the Fabaceae (pea) family, that includes approximately 250 species. All species of Dalbergia spp. were listed in the 17th Convention on International Trade in Endangered Species of Wild Fauna and Flora [9]. Dalbergia cultrate (Benth.), Dalbergia latifolia (Roxb.), and Dalbergia melanoxylon (Guill. & Perr.) are high-profile species renowned for their use in high-quality products worldwide [10,11]. These species are used in luxury furniture, artwork, and musical instruments due to their refined colors and excellent hardness and intensity properties [12,13]. Chemical and physical properties are greatly influenced by extractives, with characteristic colors and textures generating extensive market demand and heavy deforestation. Hence, these species are protected by Appendix II of CITES, D. cultrate is included in the list of national key preserved wild plants in the People’s Republic of China (first batch). However, any species appearing in Appendix II of CITES are banned from international commercial trade except for those with an import and export license or re-export certificate [14]. Therefore, a more persuasive method for distinguishing closely related species is needed.
Traditional wood anatomy identification methods based on macroscopic and microscopic characteristics have been well-established for several years [15]. However, wood anatomy is too specialized for legal identification, especially when considering leaves, flowers, fruits, and other information to provide the extent of identification required by CITES [16]. By contrast, chemotaxonomical and genetic methods are useful in wood identification [17]. Previous investigations have found chemotaxonomical identification based on the analysis of extractive compounds to be an effective method for distinguishing extremely similar wood species [18,19,20].
To the best of our knowledge, Fourier transform infrared (FTIR) spectroscopy is a fast, simple, non-destructive method and a powerful technology to determine functional groups in the fingerprint region. This approach has been widely used in identification of complex systems such as traditional Chinese medicines and is suitable for analyzing woody materials [21,22]. In recent years, research on infrared spectroscopy in wood extractive studies has grown in popularity [23,24,25]. Additionally, gas chromatography-mass spectrometry (GC-MS) offers clear advantages when analyzing complex mixtures; the combination of an ideal separation technique (GC) with a sensitive identification technique (MS) constitutes a reliable and commonly used method for qualitative and quantitative analysis of compounds [26,27,28]. GC-MS has been widely applied in establishing chromatographic fingerprints for quality evaluation of herbal medicines [29]. It has also been well-established in the characterization and identification of wood extractive compounds [30,31,32].
Little research has been carried out to identify the three similar Dalbergia species Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon based on chemical taxonomy. This paper examines differences in extractive contents and components using FTIR and GC-MS approaches to discriminate chemotaxonomically between the extractive components in Dalbergia spp. Functional group analysis using FTIR spectroscopy and detailed analysis of their components by GC-MS allow one to classify similar species by their chemical nature. These two techniques also facilitate comprehensive analysis of chemical components to support the chemotaxonomical classification of wood. GC-MS data provide a persuasive basis for specific compounds identified by infrared absorption spectra, as the two methods are complementary and valuable in chemotaxonomical identification.

2. Results and Discussion

2.1. Contents Analysis of Extractives

The extractive contents of the three Dalbergia species are listed in Table 1. Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon were extracted with four different polar organic solvents, the extractive contents were calculated, and the average value of three experiments was taken. The findings indicated that the non-polar solvent n-hexane was not suitable for wood extraction, indicating that the extractable components of these three kinds of wood are mostly polar. After successfully extracting samples with ethanol/water, benzene/ethanol, ethyl acetate respectively, the extract contents were clearly different. Among the benzyl alcohol and ethyl acetate extracts of the three species Dalbergia cultrate had the lowest content, whereas the content of Dalbergia melanoxylon was highest. With ethanol/water (9:1, v/v), the content of Dalbergia cultrate was slightly higher than that in Dalbergia latifolia but clearly lower than in Dalbergia melanoxylon. Therefore, Dalbergia melanoxylon contained more types of main compounds than Dalbergia cultrate, and Dalbergia latifolia had the fewest kinds of principle compounds, likely because it contained fewer polar components. In general, the effect of ethanol/water (9:1, v/v) was better than benzyl alcohol and ethyl acetate, and more components could be obtained. Therefore, to analyze the primary extractive components in Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon, ethanol/water (9:1, v/v) was used as the final solvent in this experiment.

2.2. FTIR Analysis

The FTIR spectra of the Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon extractives are illustrated in Figure 1. Detailed peak positions are summarized in Table 2. The characteristic infrared absorption peaks of the functional groups of the main extractive components were reflected in the FTIR spectra. In the region of 3401–2839 cm−1, all spectra exhibited strong, broad peaks attributable to the stretching vibration of O-H or N-H along with a moderate-intensity peak ascribed to methyl and methylene stretching vibrations. Benzene ring characteristic peaks (1602, 1510, and 1450 cm−1) of the three species were clear and strong, indicating a large proportion of aromatic substances [33]. However, the relative intensity of these three peaks was distinctly different. Especially for Dalbergia cultrate, the intensity of peaks at 1602 cm−1 and 1445 cm−1 was stronger, suggesting that the number, location, and properties of substituents on aromatic rings varied between the three species. Moreover, Dalbergia cultrate showed strong absorption bands around 1691 cm−1 for C=O, a peak around 1555 cm−1 with medium intensity for C=C of the aromatic ring, and strong absorption peaks at 1286 cm−1 and 1153 cm−1 for C-O-C [34]; these findings were presumably due to skeletal stretching vibration of the aromatic rings A and B and the functional group C-O-C of ring C of flavonoids [24,35]. These peaks were clearly visible only in Dalbergia cultrate; the C=O was weak for Dalbergia melanoxylon and was essentially invisible for Dalbergia latifolia, indicating an abundance of flavonoid compounds in Dalbergia cultrate.
Dalbergia cultrate also generated a stronger sharp absorption peak at 1378 cm−1. In general, methyl groups have two absorption peaks around 1375 cm−1 and 1450 cm−1, corresponding to symmetric bending vibrations and asymmetric bending vibrations, respectively [36]; this finding explains why the peak strength of Dalbergia cultrate at 1445cm−1 was so strong. Then, the absorption peaks at 1366 cm−1 of Dalbergia melanoxylon and 1352 cm−1 of Dalbergia latifolia were ascribed to either CH3 symmetrical bending or in-plane C-OH bending, as the spectral band shape was low and wide.
Peaks in the region ranging from 910 cm−1 to 1300 cm−1 were mainly due to C-O single bond stretching vibrations. The extractives of the three species exhibited clear, strong peaks at 1200 cm−1 primarily due to C-O-C stretching; however, the band intensity of the three species included typical vibrations around 1270 cm−1 (Ar-O) and 1023 cm−1 (R-O) for C-O vibrations, although the peak intensity at 1270 cm−1 in Dalbergia melanoxylon was stronger than that in Dalbergia latifolia. Dalbergia melanoxylon likely contained more aromatic ether functional groups; a peak appeared at 1130 cm−1 for C-OH stretching of the alcohol groups [36]. C-OH stretching near 1114 cm−1 was found exclusively in Dalbergia cultrate. A C-H out-of-plane bending peak was seen around 999 cm−1 in the spectrum of Dalbergia cultrate and around 917 cm−1 in the spectrum of Dalbergia latifolia. Unique vibrations near 700 cm−1 were ascribed to the stretching vibration of C-S, which was obvious in Dalbergia cultrate and Dalbergia latifolia.

2.3. GC-MS Analysis

The GC-MS chromatograms of Dalbergia cultrata, Dalbergia latifolia, and Dalbergia melanoxylon extractives are presented in Figure 2. The results show clearly the different characteristic peaks of the three species. The peak area was chosen as the analytical signal for the relative amount. The relative content of each chemical component was calculated by area normalization and the average value of the three experiments. Identified chemical components (peak area above 1.0%) and the relative content of these compounds are listed in Table 3. The main chemical components of the three species were determined to be aromatic compounds. In general, these compounds were classified into flavonoids, miscellaneous, quinones, phenols, esters, stilbenoids, and amide compounds. The components of the extracts of Dalbergia cultrata, Dalbergia latifolia, and Dalbergia melanoxylon are detailed below.
Table 3 reveals there were only two common compounds among the three species and each species also contained unique chemical components. The following three compounds were specific to Dalbergia cultrata: 3,3′,4,4′-tetramethoxystilbene (peak 3, 1.49%), 3,7,3′,4′-tetrahydroxyflavone (peak 4, 10.78%), and parietin (peak 7, 24.81%). Particular compounds found exclusively in Dalbergia latifolia included the following: 1,7,7-trimethyl-3-phenethylidenebicyclo- [2.2.1]heptan-2-one (peak 8, 3.28%), 4,4′-methylenebis-2,6-dimethylphenol (peak 9, 1.60%), 4,2′,3′,4′-tetramethoxy-5′-methyl-6-methylaminomethyl-1,1′-biphenyl (peak 10, 29.75%), (4-methyl- sulfanylphenyl)carbamic acid 2,6-dimethoxyphenyl ester (peak 11, 1.38%). GC-MS analysis of Dalbergia melanoxylon revealed five distinct compounds: 10,11-dihydro-10-hydroxy- 2,3-dimethoxydibenz(b,f)oxepin (peak 12, 4.57%), 2-(4-methoxy-2,5-dimethylphenyl)-9-methyl-2H- benzo[g]indazole (peak 13, 3.14%), 10,11-dihydro-10-hydroxy-2,3,6-trimethoxydibenz(b,f)oxepin (peak 14, 37.30%), 10,11-dihydro-2,3,6-trimethoxydibenz(b,f)oxepin-10-one (peak 15, 8.32%), and pilloin (peak 16, 7.77%).
According to the GC-MS analysis results, the principal components of the three species varied. Seven constituents were identified as having higher relative contents in Dalbergia cultrate: 3,7,3′,4′-tetrahydroxyflavone (peak 4, 10.78%), 7-methoxy-1-thioflavone (peak 5, 25.55%), and parietin (peak 7, 24.81%). 7-Methoxy-1-thioflavone is a flavonoid derivative. Some thioflavones have been reported to function as novel neuroprotective agents and exhibit antiviral activities. 3,7,3′,4′-Tetrahydroxyflavone is a natural flavonol in foods and plants and has been identified as showing various biological activities. Parietin is an anthroquinone and has been identified in the traditional Chinese herbal medicines Polygoni multiflora and Eryngium foetidum L.
Analysis also revealed the presence of eight compounds in Dalbergia latifoli with 4-methyl- 2-[5-(2-thienyl)pyrazol-3-yl]phenol (peak 1, 12.41%) and 4,2′,3′,4′-tetramethoxy-5′-methyl-6-methyl- aminomethyl-1,1′-biphenyl (peak 10, 29.75%) being the most predominant. Both compounds were previously identified in Dalbergia Stevenson based on GC-MS results [25,37]. Seven components were recognized in Dalbergia melanoxylon, with larger proportions of 10,11-dihydro-10-hydroxy-2,3,6-trimethoxydibenz(b,f)oxepin (peak 12, 37.30%), 10,11-dihydro- 2,3,6-trimethoxydibenz(b,f)oxepin-10-one (peak 14, 8.32%), and pilloin (peak 16, 7.77%). 10,11-Dihydro-10-hydroxy-2,3,6-trimethoxydibenz(b,f)oxepin was previously identified in Dalbergia Stevenson [19,37]. Pilloin is a flavonoid extracted from the Ovidia pillo-pillo plant, Marrubium cylleneum, and propolis.

3. Materials and Methods

3.1. Wood Samples

The Latin names, trade names, and places of origin of the Dalbergia species are presented in Table 4. The three Dalbergia heartwood samples were obtained from the Research Institute of Wood Industry at the Chinese Academy of Forestry, China. Figure 3 shows tangential sections of the three kinds of Dalbergia heartwood. Three replicates were analyzed per sample.

3.2. Preparation of Wood Extracts

Heartwoods were chopped into thin pieces, air-dried, and finely powdered using an electric grinder (Baijie, Hangzhou, China). Then, 40–60 mesh powders (0.2 g) were extracted in ethanol/water (10 mL, 9:1, v/v), benzene/ethanol (2:1, v/v), and ethyl acetate in an ultrasonic bath for 1 h at room temperature. Ethanol (99.8% purity), benzene (99.7% purity), ethyl acetate (99.0% purity), n-hexane (98.0% purity) were purchased from Aladdin (Shanghai, China). Next, the mixture was centrifuged for 5 min and filtered through a 0.45-µm pore size filter before the extraction solvent was dried in an oven at 103 ± 2 °C to reach a consistent weight for further analysis.

3.3. FTIR Analysis

Two mg of the 90% ethanol extract were mixed with 100 mg of KBr powder in a smooth agate mortar. Then, the mixture was ground and pressed into a transparent pellet. FTIR spectra were obtained within a scanning range of 4000–400 cm−1 at a resolution of 4 cm−1 and 16 total scans using a Spectrum ONE spectrometer (Perkin Elmer, Waltham, MA, USA) equipped with a DTGS detector at room temperature. The instrument was free of H2O and CO2.

3.4. GC-MS Analysis

GC/MS analysis was carried out by a triple quadrupole GC-MS system 450GC-320MS, (Bruker Billerica, MA, USA). Separation was achieved using a DB-5MS column (30 m × 0.25 mm × 0.25 μm; Agilent Technologies, Santa Clara, CA, USA) with a temperature program from 50 °C (5 min) to 290 °C (12 min) at 10 °C/min with helium as the carrier gas (1 mL/min). The solvent was delayed 4.5 min; the injection volume was 1 μL at a split ratio of 10. The mass spectrometer was operated in electron impact mode (70 eV), and masses were scanned over a range of 40–800 m/z. The transmission line temperature was 250 °C, and the ion source temperature was 200 °C. Peak assignment was accomplished by comparing the MS spectra to the National Institute of Standards and Technology (NIST 2010) library.

4. Conclusions

This study reveals that Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon can be successfully distinguished based on extractive analysis. Initially, the extract content of the three species was found to be different, with Dalbergia melanoxylon demonstrating the highest extractive content. By comparing different solvents, the extraction components were found to be mostly polar. Then, FTIR spectra effectively revealed additional information about the functional groups of the extractive components. We also identified the unique and primary components using GC-MS. The main chemical components of the three species varied, and 7-methoxy-1-thioflavone, 4,2′,3′,4′- tetramethoxy-5′-methyl-6-methylaminomethyl-1,1′-biphenyl and 10,11-dihydro-10-hydroxy-2,3,6- trimethoxydibenz(b,f)oxepin exhibited the highest relative content of the three species, respectively. Furthermore, each species contained its own characteristic components, a useful finding for distinguishing between the three species. In summary Dalbergia cultrate, Dalbergia latifolia, and Dalbergia melanoxylon can be distinguished successfully according to differences in extractive content, functional groups, and chemical composition.

Author Contributions

X.Y. performed the experiments, analyzed the data, and wrote the manuscript; A.H. conceived and designed the experiments; S.Z. reviewed the manuscript; R.L. and F.M. contributed to the analysis tools.

Funding

This work was supported by the National Natural Science Foundation of China (No. 31670564).

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Hillis, W.E. Heartwood and Tree Exudates; Springer: Berlin, Germany, 1987; pp. 76–119. [Google Scholar]
  2. Roffael, E. Significance of wood extractives for wood bonding. Appl. Microbiol. Biotechnol. 2015, 100, 1589–1596. [Google Scholar] [CrossRef] [PubMed]
  3. Hillis, W.E. Distribution, properties, and formation of some wood extractives. Wood Sci. Technol. 1971, 5, 272–289. [Google Scholar] [CrossRef]
  4. Schultz, T.P.; Nicholas, D.D. Naturally durable heartwood evidence for a proposed dual defensive function of the extractives. Phytochemistry 2000, 54, 47–52. [Google Scholar] [CrossRef]
  5. Umezawa, T. Chemistry of extractives. In Wood and Cellulosic Chemistry; Taylor Francis Inc.: New York, NY, USA, 2000. [Google Scholar]
  6. Tittikpina, N.K.; Nana, F.; Fontanay, S.; Philippot, S.; Batawila, K.; Akpagana, K. Antibacterial activity and cytotoxicity of pterocarpus erinaceus poir extracts, fractions and isolated compounds. J. Ethnopharmacol. 2018, 212, 200–207. [Google Scholar] [CrossRef] [PubMed]
  7. Nagawa, C.B.; Böhmdorfer, S.; Rosenau, T. Chemical composition of volatiles extracted from indigenous tree species of Uganda: Composition of bark extracts from Psorospermum febrifugum and Milicia excelsa. Holzforschung 2015, 69, 815–821. [Google Scholar] [CrossRef]
  8. Seshadri, T.R. Polyphenols of Pterocarpus and Dalbergia woods. Phytochemistry 1972, 11, 881–898. [Google Scholar] [CrossRef]
  9. Convention on International Trade in Endangered Species of Wild Fauna and Flora. Appendices I, II, and III; Government of South Africa: Johannesburg, South Africa, 24 September 2016.
  10. Li, Q.; Wu, J.; Wang, Y.; Lian, X.; Wu, F.; Zhou, L. The phylogenetic analysis of Dalbergia (fabaceae: Papilionaceae) based on different DNA barcodes. Holzforschung 2017, 71, 939–949. [Google Scholar] [CrossRef]
  11. Jenkins, M.; Oldfield, S.; Aylett, T.; Jenkins, M.; Oldfield, S.; Aylett, T. International Trade in African Blackwood; Fauna and Flora International: Cambridge, UK, 2002. [Google Scholar]
  12. Barrett, M.A.; Brown, J.L.; Morikawa, M.K.; Labat, J.; Yoder, A.D. CITES Designation for endangered rosewood in Madagascar. Science 2010, 328, 1109–1110. [Google Scholar] [CrossRef] [PubMed]
  13. Hassold, S.; Ii, P.P.L.; Bauert, M.R.; Razafintsalama, A.; Ramamonjisoa, L.; Widmer, A. DNA barcoding of malagasy rosewoods: Towards a molecular identification of cites-listed Dalbergia species. PLoS ONE 2016, 11. [Google Scholar] [CrossRef] [PubMed]
  14. APPENDIX. A Summary of the Criteria for the Three CITES Appendices. Available online: https://www.cites.org (accessed on 8 May 2018).
  15. Richter, H.G.; Krause, V.J.; Muche, C. Wood Structure and physico-chemical properties compared with other central American species of Dalbergia. IAWA J. 1996, 17, 327–341. [Google Scholar] [CrossRef]
  16. Gasson, P.; Miller, R.; Stekel, D.J.; Whinder, F.; Zieminska, K. Wood identification of Dalbergia nigra (Cites Appendix I) using quantitative wood anatomy, principal components analysis and nacve bayes classification. Ann. Bot. 2010, 10545–10546. [Google Scholar]
  17. Wu, C.C.; Chu, F.H.; Ho, C.K.; Sung, C.H.; Chang, S.H. Comparative analysis of the complete chloroplast genomic sequence and chemical components of cinnamomum micranthum and cinnamomum kanehirae. Holzforschung 2017, 71, 189–197. [Google Scholar] [CrossRef]
  18. Kite, G.C.; Green, P.W.C.; Veitch, N.C.; Groves, M.C.; Gasson, P.E.; Simmonds, M.S.J. Dalnigrin, a neoflavonoid marker for the identification of brazilian rosewood (Dalbergia nigra) in cites enforcement. Phytochemistry 2010, 71, 1122–1131. [Google Scholar] [CrossRef] [PubMed]
  19. Wang, S.; Zhang, F.; Huang, A.; Zhou, Q. Distinction of four Dalbergia species by FTIR, 2nd derivative IR, and 2D-IR spectroscopy of their ethanol-benzene extractives. Holzforschung 2016, 70, 503–510. [Google Scholar] [CrossRef]
  20. Vidaković, V.; Novaković, M.; Popović, Z.; Janković, M.; Matić, R.; Tešević, V. Significance of diarylheptanoids for chemotaxonomical distinguishing between Alnus glutinosa and Alnus incana. Holzforschung 2017, 72, 9–16. [Google Scholar] [CrossRef]
  21. Huang, A.; Zhou, Q.; Liu, J.; Fei, B.; Sun, S. Distinction of three wood species by Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy. J. Mol. Struct. 2008, 883, 160–166. [Google Scholar] [CrossRef]
  22. Ma, F.; Huang, A. Rapid identification and quantification three chicken-wing woods of Millettia leucantha, Millettia laurentii and Cassia siamea by FT-IR and 2DCOS-IR. J. Mol. Struct. 2018, 1166, 164–168. [Google Scholar] [CrossRef]
  23. Luo, S.; Wu, Y.; Huang, J. Thermal and Chemical Properties of Benzene/Alcohol Extractives from Two Species of Redwood. In Proceedings of the 2012 International Conference on Biobase Material Science and Engineering (BMSE), Changsha, China, 21–23 October 2012; pp. 156–160. [Google Scholar]
  24. Zhang, F.; Xu, C.; Li, M.; Chen, X.; Zhou, Q.; Huang, A. Identification of Dalbergia cochinchinensis (cites appendix ii) from other three Dalbergia, species using ft-ir and 2d correlation ir spectroscopy. Wood Sci. Technol. 2016, 50, 693–704. [Google Scholar] [CrossRef]
  25. Wang, F.; Huang, A.; Yin, X.; Wang, W.; Chen, J. Multilevel profiling and identification of Dalbergia odorifera and Dalbergia stevensonii by FTIR, NMR and GC/MS. Chin. Chem. Lett. 2017, 29, 1395–1398. [Google Scholar] [CrossRef]
  26. Iordache, A.; Culea, M.; Gherman, C. Characterization of some plant extracts by GC-MS. Nucl. Instrum. Methods Phys. Res. B 2009, 267, 338–342. [Google Scholar] [CrossRef]
  27. Mangindaan, B.; Matsushita, Y.; Aoki, D.; Yagami, S.; Kawamura, F.; Fukushima, K. Analysis of distribution of wood extractives in gmelina arborea by gas chromatography and time-of-flight secondary ion mass spectrometry. Holzforschung 2017, 71, 299–305. [Google Scholar] [CrossRef]
  28. Liu, R.; Wang, C.; Huang, A.; Lv, B. Characterization of Odors of Wood by Gas Chromatography-Olfactometry with Removal of Extractives as Attempt to Control Indoor Air Quality. Molecules 2018, 23, 203. [Google Scholar] [CrossRef] [PubMed]
  29. Pan, R.; Guo, F.; Lu, H.; Feng, W.; Liang, Y. Development of the chromatographic fingerprint of scutellaria barbata D. Don by GC-MS combined with chemometrics methods. J. Pharm. Biomed. Anal. 2011, 55, 391–396. [Google Scholar] [CrossRef] [PubMed]
  30. Fernandez, M.P.; Watson, P.A.; Breuil, C. Gas chromatography-mass spectrometry method for the simultaneous determination of wood extractive compounds in quaking aspen. J. Chromatogr. A 2001, 922, 225–233. [Google Scholar] [CrossRef]
  31. Vaysi, R. Identification and comparison of chemical components in wood and bark of planted eldar pine tree by GC/MS methods. Pro Ligno 2014, 10, 21–25. [Google Scholar]
  32. Xu, B.; Zhu, T.; Li, J.; Liu, S. Identification of wood between Phoebe zhennan and Machilus pingii using the gas chromatography-mass spectrometry direct injection technique. Eur. J. Mass Spectrom. 2013, 19, 187–193. [Google Scholar] [CrossRef]
  33. Zhang, Z.; Li, H.; Sun, S.; Huang, L.; Noda, I. Differentiation of Rhizoma Curcumas longae and Radix Curcumae by a multistep infrared macro-fingerprint method. Anal. Lett. 2013, 46, 2597–2609. [Google Scholar] [CrossRef]
  34. Xu, R.; Sun, S.; Zhu, W. Multi-step infrared macro-fingerprint features of ethanol extracts from different Cistanche species in China combined with HPLC fingerprint. J. Mol. Struct. 2014, 1069, 236–244. [Google Scholar] [CrossRef]
  35. Liu, Y.; Li, J.; Fan, G.; Sun, S.; Zhang, Y.; Zhang, Y. Identification of the traditional tibetan medicine “shaji” and their different extracts through tri-step infrared spectroscopy. J. Mol. Struct. 2016, 1124, 180–187. [Google Scholar] [CrossRef]
  36. Sun, S.; Zhou, Q.; Chen, J. Infrared Spectroscopy for Complex. Mixtures: Applications in Food and Traditional Chinese Medicine; Chemical Industry Press: Beijing, China, 2011; pp. 58–61. [Google Scholar]
  37. Jiang, S.; Ge, S.; Wang, M.; Peng, W. Molecules and functions of rosewood: Dalbergia stevenson. Arab. J. Chem. 2017. [Google Scholar] [CrossRef]
Sample Availability: Samples of the compounds are not available from the authors.
Figure 1. FTIR spectra: (a) D. cultrate, (b) D. latifolia, (c) D. melanoxylon.
Figure 1. FTIR spectra: (a) D. cultrate, (b) D. latifolia, (c) D. melanoxylon.
Molecules 23 02163 g001
Figure 2. Total ion chromatogram: (a) D. cultrate, (b) D. latifolia, (c) D. melanoxylon.
Figure 2. Total ion chromatogram: (a) D. cultrate, (b) D. latifolia, (c) D. melanoxylon.
Molecules 23 02163 g002
Figure 3. Heartwood of (a) Dalbergia cultrate, (b) Dalbergia latifolia and (c) Dalbergia melanoxylon.
Figure 3. Heartwood of (a) Dalbergia cultrate, (b) Dalbergia latifolia and (c) Dalbergia melanoxylon.
Molecules 23 02163 g003
Table 1. Comparison of extractive contents in different solvents.
Table 1. Comparison of extractive contents in different solvents.
SpeciesYield of Extractives (%)
Ethanol/Water
(9:1, v/v)
Benzene/Ethanol
(2:1, v/v)
Ethyl Acetaten-Hexane
Dalbergia cultrate11.68.66.2-
Dalbergia latifolia10.19.656.8-
Dalbergia melanoxylon16.6516.0513.0-
Table 2. FTIR band assignment.
Table 2. FTIR band assignment.
Wavenumbers(cm−1)
D. CultrataD. LatifoliaD. MelanoxylonBand Assignments
338134003401O-H stretch; N-H stretch
293229332935C-H stretch: CH2
284928392841C-H stretch:CH3
169116691675C=O stretch; C=N stretch
160216021602C=C stretching of aromatic skeleton
1555--C=C stretching of aromatic skeleton
151015081510C-C stretch bands within ring skeleton
-1452-Skeletal C-C stretching; CH3 symmetrical bending vibrations ;CH2 scissoring
1445 1444Aromatic stretching(flavonoids); CH3 symmetrical bending vibrations
1378--CH3 asymmetrical bending vibrations
1366CH3 symmetrical bending; in-plane C-OH bending
rical bending
-1352 CH3 symmetrical bending; in-plane C-OH bending
C-N-C asymmrtric vibration of aromatic compounds
-1318-in-plane C-OH bending; C-O stretching
1286--C-O-C stretching (flavonoids)
-12701273C-O vibration
120312001199C-O-C stretching
-1170-C-O stretching
C-O-C stretching or frame vibration (flavonoids)
1153--C-O-C stretching(flavonoids); in-plane C-OH bending
C-O-C stretching or frame vibration (flavonoids)
--1130C-OH stretching
1114--C-OH stretching
101610291023C-O stretching
999--C-H out-of-plane bend
C-O stretching
-917-C-H out-of-plane bend
875878874C-O stretching
-839836C-H stretching out of plane of aromatic ring; C-N wagging
699700 C-H stretching out of plane of aromatic ring; C-S stretching
Table 3. Chemical composition of extractives analyzed by GC/MS.
Table 3. Chemical composition of extractives analyzed by GC/MS.
IDRT(min)CompoundsMolecular StructureReleative Content (%) *
D. CultrateD. LatifoliaD. Melanoxylon
124.97Phenol,4-methyl-2-[5-(2-thienyl)pyrazol-3-yl]- Molecules 23 02163 i0014.7612.41 (0.7)1.47
629.6613-Docosenamide, (Z)- Molecules 23 02163 i0022.08 (0.2)2.17 (0.2)1.26 (0.1)
225.13Naphtho[2,3-b]furan-4,9-dione, 2-isopropyl- Molecules 23 02163 i0031.541.36 (0.2)-
528.901-Thioflavone, 7-methoxy- Molecules 23 02163 i00425.55 (0.2)4.23-
326.443,3′,4,4′-Tetramethoxystilbene Molecules 23 02163 i0051.49--
427.263,7,3′,4′-Tetrahydroxyflavone Molecules 23 02163 i00610.78 (0.1)--
732.49Parietin Molecules 23 02163 i00724.81 (0.4)--
824.111,7,7-Trimethyl-3-phenethylidenebicyclo[2.2.1]heptan-2-one Molecules 23 02163 i008-3.28-
924.73Phenol, 4,4′-methylenebis[2,6-dimethyl- Molecules 23 02163 i009-1.60-
1026.321,1′-Biphenyl, 4,2′,3′,4′-tetramethoxy-5′-methyl-6-methylaminomethyl- Molecules 23 02163 i010-29.75 (0.8)-
1127.88(4-Methylsulfanylphenyl)carbamic acid, 2,6-dimethoxyphenyl ester Molecules 23 02163 i011-1.38-
1227.7610,11-Dihydro-10-hydroxy-2,3- dimethoxydibenz(b,f)oxepin Molecules 23 02163 i012--4.57
1328.662-(4-Methoxy-2,5-dimethyl-phenyl)-9-methyl-2H-benzo[g]indazole Molecules 23 02163 i013--3.14
1428.8810,11-Dihydro-10-hydroxy-2,3,6-trimethoxydibenz(b,f)oxepin Molecules 23 02163 i014--37.30 (0.8)
1530.0610,11-Dihydro-2,3,6-trimethoxydibenz(b,f)oxepin-10-one Molecules 23 02163 i015--8.32 (0.2)
1634.86Pilloin Molecules 23 02163 i016--7.77 (0.1)
* The percentage was calculated based on the peak area. Values in the parentheses are the deviations of three replicates. Deviations lower than 0.1% are not listed in the table.
Table 4. Latin and trade names and places of origin of investigated Dalbergia species.
Table 4. Latin and trade names and places of origin of investigated Dalbergia species.
Latin NameTrade NamePlace of Origin
Dalbergia cultrate Benth.Burmese blackwoodLaos
Dalbergia latifolia Roxb.Indian rosewoodIndonesia
Dalbergia melanoxylon (Guill. & Perr.)African blackwoodMozambique

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Yin, X.; Huang, A.; Zhang, S.; Liu, R.; Ma, F. Identification of Three Dalbergia Species Based on Differences in Extractive Components. Molecules 2018, 23, 2163. https://doi.org/10.3390/molecules23092163

AMA Style

Yin X, Huang A, Zhang S, Liu R, Ma F. Identification of Three Dalbergia Species Based on Differences in Extractive Components. Molecules. 2018; 23(9):2163. https://doi.org/10.3390/molecules23092163

Chicago/Turabian Style

Yin, Xiaoqian, Anmin Huang, Shifeng Zhang, Ru Liu, and Fang Ma. 2018. "Identification of Three Dalbergia Species Based on Differences in Extractive Components" Molecules 23, no. 9: 2163. https://doi.org/10.3390/molecules23092163

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