Physalis angulata L. is an annual herb belonging to the family Solanaceae and is widely distributed in tropical and temperate regions. It is a common herbal plant, known in Chinese as kuzhi, which has been used as a folk medicine with antiinflammatory, antitussive, antipyretic, diuretic, antidotal, and antitumor effects in Taiwan. 1) The extracts and components of this plant were found to have antitumor, 2,3) cytotoxic, [4][5][6][7][8] inhibition of the ubiquitin-proteasome pathway, 9) immunomodulatory, 10) antimycobacterial, 11) antinociceptive, antiinflammatory, and antiallergic activities. 12)Physalis angulata is known to contain a wide variety of pharmacologically important steroidal compounds, such as withasteroids.4) To date, phytochemical studies of this plant have described the isolation of numerous phytochemicals, including withasteroids, [4][5][6]8,[13][14][15][16][17] flavonoid glycoside, 18) and alkaloids. 19) In a previous study, we isolated a withanolide, withangulatin A (1), 15) with significant biological activities 20) from this plant as a part of our search for bioactive constituents from natural sources. Here, we report the isolation and structural elucidation of a minor withanolide, withangulatin I (2), from this plant. Its structure was established as (20S,22R)-15a-acetoxy-5b,6b-epoxy-14a-hydroxy-1,4-dioxo-witha-2,16,24-trienolide on the basis of extensive spectroscopic data interpretation, chemical transformation, and circular dichroism (CD) experiments. The cytotoxic activities of compounds 1 and 2 against human colorectal carcinoma COLO 205 and human gastric carcinoma AGS cell lines were also evaluated in vitro. Results and DiscussionAs in the previously reported procedure, 15) the fractions containing withanolides were combined. The combined fractions were further purified by repeated column chromatography and preparative TLC to afford a minor withanolide, withangulatin I (2). The structure of 2 was established based on detailed spectral analyses, chemical transformation, and comparison with the spectral data reported in the literature.Compound 2 was isolated as a pale yellow, amorphous powder. The IR spectrum of 2 displayed absorption bands of hydroxyl (3450 cm 22) The EI-MS spectrum showed a base peak at m/z 125 which confirmed the presence of the a,b-unsaturated d-lactone moiety.23) These data revealed that compound 2 is a typical withanolide bearing an acetoxyl group and a D 2 -1,4-dione moiety. The deshielding proton A new withanolide, withangulatin I (2), was isolated from the whole plant of Physalis angulata. Its structure was established as (20S,22R)-15a a-acetoxy-5b b,6b b-epoxy-14a a-hydroxy-1,4-
A new sulfated cucurbitacin, cucurbitacin B 2-sulfate (1) and a new cucurbitacin glucoside, cucurbitacin G 2-O-b b-D-glucopyranoside (2) together with two known cucurbitacin glucosides, arvenin I and arvenin III were isolated from the root bark of Helicteres angustifolia. The structures of these compounds were established on the basis of spectroscopic and chemical evidence. These four compounds taste of strong bitterness. Compound 1 is a first sulfated cucurbitacin found in plants.
A naphthohydroquinone and eight anthraquinones were isolated from the roots of Rubia lanceolata Hayata. Their structures were assigned as mollugin (1), l‐hydroxy‐2‐methyl‐9,10‐anthraquinone (2), 2‐methylquinizarin (3), 3‐carbomethoxy‐l‐hydroxy‐9,10‐anthraquinone (4), lucidin ethyl ether (5), rubiadin (6), alizarin (7), ω‐hydroxypachybasin (8) and digiferruginol (9) on the basis of spectral evidence. Among them, compounds 8 and 9 were isolated for the first time from Rubia species.
Steroids U 0300Cucurbitacin B 2-Sulfate and Cucurbitacin Glucosides from the Root Bark of Helicteres angustifolia. -The new cucurbitacins cucurbitacin B 2-sulfate (Ia) and cucurbitacin G (Ib) are isolated together with the known cucurbitacin glucosides arvenin I and arvenin III. Compound (Ia) is the first sulfated cucurbitacin found in plants. All four compounds taste of strong bitterness. -(CHEN*, Z.-T.; LEE, S.-W.; CHEN, C.-M.; Chem.
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