Essential oil components in the seed masses of Amomum xanthioides and its related species from Southeast Asia and China.

Previously, to develop an objective identification method for Amomi Semen (AS), the nucleotide sequences of nrDNA ITS region and two cpDNA regions of nine Amomum taxa specimens from Southeast Asia and China were determined, and the generated phylogenetic tree showed six taxa specimens were divided into four groups. In this study, 51 crude drug samples of AS in Japanese markets were classified into four groups or species based on their ITS sequences. Approximately 67% of samples were derived from A. villosum var. xanthioides or A. xanthioides, A. villosum var. villosum and A. longiligulare prescribed in Japanese Pharmacopoeia, and the rest were mixed with A. uliginosum and A. microcarpum. Subsequently, the essential oil compositions of Amomum taxa specimens and AS samples were determined by GC-MS to characterize each group or species. Group 1(A. xanthioides) samples were characterized by containing higher amount of camphor(6) than bornyl acetate(9), and a specific germacrene D-4-ol; group 2(Chinese A. villosum var. villosum and var. xanthioides) by containing higher amount of 9 than 6, a specific isobornyl acetate; group 3(Laotian A. villosum var. villosum and A. longiligulare) by containing higher amount of 6 than 9, and a characteristic neointermedeol, except for A. longiligulare specimen from Hainan, China; group 4(A. uliginosum) by containing equivalent amount of 6 and 9, and the specific (E,E)-farnesyl acetate and (E,E)-farnesol. A. microcarpum samples were discriminated from the above groups by absence of 6 and 9, and with higher amount of (E)-nerolidol. There was a good correlation between genetic classification and chemical discrimination.

Genetic diversity of Amomum xanthioides and its related species from Southeast Asia and China.

Amomum Semen, the seed mass of Amomum xanthioides, has been imported from Southeast Asia and China and used for the treatment of gastric and intestinal disorders. A. xanthioides has been treated as a synonym of A. villosum var. xanthioides. Furthermore, A. villosum var. villosum, A. villosum var. xanthioides, or A. longiligulare have been described as the botanical origin of Amomi Fructus, which is a similar crude drug in Chinese Pharmacopoeia. Under these circumstances, the botanical origin of Amomum Semen was changed to A. villosum var. xanthioides, A. villosum var. villosum, or A. longiligulare in Supplement II to the 17th edition of the Japanese Pharmacopoeia. To develop an objective identification method for Amomum Semen and to confirm the phylogenetic relationship among Amomum taxa, the nucleotide sequences of the nuclear ribosomal DNA internal transcribed spacer region and chloroplast DNA partial matK-trnK and trnH-psbA intergenic spacer regions were determined in specimens collected from Southeast Asia and China, including those from the type localities of each taxon. Six taxa were divided into four groups. A. xanthioides from Myanmar belonging to group 1 was discriminated from A. villosum var. xanthioides from China of group 2. A. villosum and its varieties were divided into two groups: group 2 included those from China, and group 3 consisted of A. villosum from Laos. A. longiligulare from China and Laos and A. uliginosum from Laos belonged to group 3 and group 4, respectively. These findings illustrate the phylogenetic basis for the need for taxonomical reorganization among the Amomum species.