Aristolochic acids （AAs） and aristololactams （ALs） are commonly found in some Aristolochiaceae plants, and they have been reported to be AA nephropathy （AAN）, nephrotoxicity and carcinogenicity. In the present study, we established an ultra high performance liquid chromatography （UHPLC） coupled with quadmpole/time-of-flight mass spectrometry （Q/TOF-MS） method for the rapid analysis of eight AA analogues in 19 samples originated from the five Aristolochiaceae plants, the roots and rhizomes ofAsarum sieboldii Miq. var. seoulense Nakai, the fruits ofAristolochia contorta Bunge or A. debilis Sieb. et Zucc., the roots ofAristolochia debilis Sieb. et Zucc., the stems ofAristolochia manshuriensis Kom., and the roots of Aristolochiafangchi Y. C. Wu ex L. D. Chou et S. M. Hwang. A total of five AAs and three ALs were identified by co-chromatography of sample extract and comparing the retention time, UV spectra, and characteristic molecular ions and fragment ions with those of authentic standards, or tentatively identified by MS/MS determination along with Mass Fragment software. Moreover, the method was validated for the simultaneous quantification or semi-quantification of them. The samples significantly differed in the quality and quantity of AA analogues, which aUowed the possibility of showing their chemical distinctness, and it might be helpful in their standardization and quality control. Furthermore, in order to holistically compare the difference between the five Aristolochiaceae plants, dataset obtained from UHPLC-Q/TOF-MS was processed with principal component analysis （PCA） and orthogonal partial least squared discriminant analysis （OPLS-DA）.
In the present study, the chemical composition, antinociceptive effect and acute toxicity of essential oils（EOs） of Asarum heterotropoides Fr. Schmidt var. mandshuricum（Maxim.） Kitag.（AHM）, A. sieboldii Miq. var. seoulense Nakai（ASS） and A. himalaicum Hook. f. et Thoms. ex Klotzsch.（AH） were comparatively evaluated. A total of 55 compounds were identified in EOs of AHM, ASS and AH by GC-MS. Methyleugenol（20.16%–62.89%）, safrole（2.67%–32.42%）, 3,5-dimethoxytoluene（2.00%–18.59%） and eucarvone（1.52%–19.16%） were the major constituents of EO of AHM, and methyleugenol（48.35%–61.06%）, eucarvone（11.13%–13.93%） and elemicin（4.79%–11.14%） were the major constituents of EO of ASS. The EO of AH was different from that of AHM and ASS, in which patchouli alcohol（27.42%–51.95%） and elemicin（13.11%–42.23%） were found in a greater amount. Moreover, the antinociceptive effect of EOs of AHM（5.5, 11.0, 16.5 μL/kg） and AH（2.0, 4.0, 6.0 μL/kg） was comparatively assayed in acetic acid-induced writhing, hot plate and formalin tests. The results indicated a weak central, but potent peripheral antinociceptive effect of EO of AHM, and more potent central and peripheral antinociceptive effect of EO of AH. The LD50 of the EOs of AHM and AH were 1.7 and 7.7 mL/kg, respectively. These findings suggest that EOs of AHM and AH possess evident antinociceptive activity and are probably safe within the range of its clinical doses. However, their chemical compositions are quite different. Therefore, AH can be clinically used as an herbal medicinal product with broad analgesic effects, but should not be confused with AHM and ASS used in traditional Chinese medicine.
