Yunfa Dong

Two Novel Ceramides with a Phytosphingolipid and a Tertiary Amide Structure from Zephyranthes candida

Two novel ceramides, Candidamide A (1) with a phytosphingolipid structure, and Candidamide B (2) with a tertiary amide structure, together with 12 known compounds (3–14) have been isolated from the bulbs of Zephyranthes candida, The structures of 1 and 2 have been elucidated to be 1,3,5,6-tetrahydroxy-2-(2′-hydroxytetracosanoyl amino)-8-(E)-octadecadiene (1) and (2S,3S,4R,8E,2′R)-2-[N-(2′-hydroxyoctadecanoyl)-N-(1′′,2′′-dihydroxyethyl)-amino]-8-hexacosene-1,3,4-triol (2) on the basis of spectroscopic evidence including IR, MS, NMR (1H-NMR, 13C-NMR, DEPT, 1H–1H COSY, HSQC, HMBC). The known compounds were identified as (2S)-3′,7-dihydroxy-4′-methoxyflavan (3), (2S)-4′-hydroxy-7-methoxyflavan (4), (2S)-4′,7-dihydroxyflavan (5), 7-hydroxy-3′, 4′-methylenedioxyflavan (6), ambrettolide (7), β-sitostero1 (8), β-daucosterin (9), rutin (10), pancratistatin (11), lycorine (12), haemanthidine (13), and haemanthamine (14). In the antimicrobial assay, candidamide A (1) and candidamide B (2) displayed moderate activities against bacteria Staphylococcus aureus and Escherichia coli, and fungi Aspergillus niger, Candida albicans and Trichophyton rubrum.

New flavonoid-C-glycosides from Triticum aestivum

Two new flavonoid-C-glycosides named triticuside A (1a) and triticuside B (1b) were isolated from bran of Triticum aestivum L. The structures of the two new compounds were elucidated by spectral techniques including 1H NMR, 13C NMR as well as HSQC, HMBC, and COSY.

The first chlorogenic acid ester saponin from Lonicera macranthoides

An original triterpenoid saponin, named lonimacranthoide I, was isolated from the flower buds of Lonicera macranthoides (Caprifoliaceae). It has hederagenin as aglycone. Lonimacranthoide I is a rare chlorogenic acid ester acylated at C-23 of hederagenin. The structure of the saponin was established based on chemical and spectral methods.

Amino-acid and mineral composition of Stellaria media

Stellaria media (L.) Vill. (Caryophyllaceae) is well known as an invasive weed in gardens, fields, and disturbed grounds in the world [1, 2], but this plant is also a Chinese traditional medicinal plant used for hundreds of years by the Chinese community, which shows very effective anti-inflammatory and antiviral activities [3]. In both Europe and North America, it also has a very long history of herbal use, which is particularly beneficial in the external treatment of kinds of itching skin conditions [4]. But not all of these uses are supported by scientific evidence. The goal of our work was to study the amino acid and mineral composition of the aerial part of S. media. Samples of raw material were collected during flowering in Nanjing Botanical Garden, Mem. Sun Yat-sen (China). We investigated the amino acid composition by using a Hitachi 835-50 mould automatic amino-acid analyzer. For this, the sample was extracted exhaustively with hot water, filtered, and evaporated to dryness in vacuo. The dry solid was treated with lithium citrate buffer (pH 2.2). Proteins were precipitated by sulfosalicylic acid solution (0.1 mL, 30%). The samples were centrifuged and analyzed. The qualitative amino-acid composition in the studied sample was determined from retention times using a standard mixture consisting of 24 amino acids as a standard. The quantitative amino acids content was calculated in mg/kg of sample. Table 1 gives the results. A total of 16 free amino acids were observed in S. media. Of these, 9 were essential (threonine, valine, methionine, isoleucine, leucine, phenylalanine, lysine, and histidine and arginine, which are not synthesized in children). Bound amino acids were determined after modified acid hydrolysis by HCI (5.7 N) at 130 C for 6 h. A total of 16 amino acids was observed in the sample. The total content of free essential amino acids in S. media was 0.85% (27.27% of the total free amino acids); that of bound essential amino acids was 7.39% (48.05% of the total bound amino acids). This indicated that proteins from the aerial part of S. media were complete. Glutamic acid dominated in the investigated sample. The macroand microelement compositions of the herb was established by inductively coupled plasma optical emission spectrometry (ICP-OES) using a Perkin–Elmer OPTIMA 4300DV spectrograph [5]. The employed method enabled the determination of 21 elements in the herb. Table 2 gives the results. The contents of toxic and potentially toxic elements decreased in the order Al > Ti > Ba > Ag > Pb, which were below the minimum acceptable concentrations [3]. The presence of essential amino acids and essential and biogenic chemical elements will determine the potential for S. media and preparations of it for treatment of many diseases that are due to their deficiency in the organism.

New coumarin glucoside from Angelica dahurica

A new linear furanocoumarin glycoside named dahurin B (1) was isolated from the fresh roots and rhizomes of Angelica dahurica. The structure of the new compound was elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, and COSY.

A biflavonoid from stems and leaves of Lonicera macranthoides

A new biflavonoid, 3′′′-O-methylamentoflavone (1), as well as a known biflavonoid, amentoflavone (2), was isolated from the stems and leaves of Lonicera macranthoides Hand.-Mazz.Their structures were established on the basis of 1D, 2D NMR (HSQC and HMBC), and ESI-TOF-MS spectroscopic methods and chemical evidence.

Another two novel ceramides from Zephyranthes candida

From the the bulbs of Zephyranthes candida (Amaryllidaceae), another two novel ceramides have been isolated and identified. The structures of the two novel compounds were established as (2S,3S,4R,21E,2′R)2-[N-(2′-hydroxynonadecanoyl)-N-(1′′,2′′-dihydroxyethyl)amino]-21-hexacosene-1,3,4-triol, named zephyranamide C (1), and 1,3,4,5,6-pentahydroxy-2-(2′-hydroxyhexacosanoyl-amino)-18-(E)-tetracosene, named zephyranamide D (2). Their structures and stereochemistries were elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, DEPT, and COSY.

Two new ceramides from Zephyranthes candida

Two new ceramides were isolated from the bulbs of Zephyranthes candida. Their structures were established as (2S,3S,4R,13E)-1,3,4-trihydroxy-2-[(2′R)-2′-hydroxytetracosanoylamino]-13-octadecene, named zephyranamide A (1) and (2S,3S,4R)-1,3,4-trihydroxy-2-octacosanoylaminohexadecene, named zephyranamide B (2). The structures of the new compounds were elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, DEPT, and COSY.

Two new linear furanocoumarin glycosides from Angelica dahurica

Two new linear furanocoumarin glycosides, tert-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-oxypeucedanin hydrate (1) and sec-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-oxypeucedanin hydrate (2), were isolated from the fresh roots of Angelica dahurica. The structures of new compounds were elucidated on the basis of spectral analysis.

Two new coumarin biosides from Angelica dahurica

Two new coumarin biosides, tert-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-byakangelicin (1) and 2′-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranosyl-peucedanol (2), were isolated from the fresh roots of Angelica dahurica. The structures of the new compounds were elucidated on the basis of spectral analysis.