2018 Springer Science+Business Media, LLC
Chemistry of Natural Compounds, Vol. 54, No. 3, May, 2018
A NEW KAURANE DITERPENE FROM THE SEEDS
OF Vernonia anthelmintica
and H. A. Aisa
A new kaurane diterpene, 16
-hydroxykauran (1), and four known octadecenoic acid
derivatives,12,13,17-trihydroxy-9(Z)-octadecenoic acid methyl ester (2), 12,13,17-trihydroxy-9(Z)-
octadecenoic acid (3), tianshic acid (4), and 1,3-divernolin (5), were isolated from the seeds of Vernonia
anthelmintica. Their structures were elucidated based on extensive spectroscopic analysis.
Keywords: Vernonia anthelmintica, diterpene, octadecenoic acid derivatives.
Vernonia anthelmintica, belonging to the Compositae family, is mainly distributed in high-altitude areas of southern
Xinjiang, India, and Pakistan. The seeds of the plant are called Kaliziri in traditional Uyghur medicine (TUM), and it is a
famous folk medicine to cure vitiligo. Previous phytochemical studies on the plant resulted in the isolation of diverse components
including elemanolide dimers >1, 2@, sesquiterpenoids >3@, flavonoids >4@, triterpenoids >5@, steroids >5, 6@, and caffeoylquinic
acid >7@. Investigation of the seeds of V. anthelmintica led to the isolation of a new kaurane diterpene, named 16
-hydroxykauran (1), and four known octadecenoic acid derivatives, 12,13,17-trihydroxy-9(Z)-octadecenoic acid methyl
ester (2) , 12,13,17-trihydroxy-9(Z)-octadecenoic acid (3) >8@, tianshic acid (4) >9@, and 1,3-divernolin (5) >10@. Their
structures were determinated by spectroscopic methods, mainly 1D and 2D NMR.
Compound 1 was obtained as a white amorphous powder with molecular formula of C
, which was confirmed
by (+)HR-ESI-MS at m/z 385.5351 [M + Na]
(calcd for C
Na, 385.5358). The
H NMR spectrum (Table 1) showed the
presence of five methyls at 0.77, 0.97, 1.01, 1.35, and 1.38 (each 3H, s). The
C NMR spectrum showed the presence of 23 carbons.
There was a typical signal at G 108.5; according to the literature >11, 12@, it is a carbon of an isopropylidenedioxy group.
H NMR and
C NMR spectra data (Table 1) were very close to the spectra of 16
,17-acetonide of ent-16
dihydroxykauran-19-oic acid >12@. Comparing the
C NMR data of 1 to those in the literature, we see that the carbonyl and the
methoxyl group were not present and there was one more methyl group in 1, and also the signal at G 38.5 was replaced by G 79.1.
In the HSQC spectrum, the proton at G 3.18 (dd, J = 11.1, 5.3 Hz) was on the carbon at G 79.1, which meant that the H
,17-acetonide of ent-16
,17-dihydroxy-kauran-19-oic acid at C-4 was replaced by a methyl, and a hydroxyl group was
located at C-3. The differences were confirmed by the correlations between H
-19 and C-3, H
-19 and C-4, H
and C-19, and H
-19 and C-18 in the HMBC spectrum. The relative configuration of 1 was established by the NOESY spectrum.
1) Key Laboratory of Plant Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and
Chemistry, Chinese Academy of Sciences, 830011, Urumqi, P. R. China, fax: +86 991 3838957, e-mail: firstname.lastname@example.org;
2) State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of
Physics and Chemistry, Chinese Academy of Sciences, 830011, Urumqi, P. R. China. Published in Khimiya Prirodnykh
Soedinenii, No. 3, May–June, 2018, pp. 403–404. Original article submitted December 4, 2016.