Biomedical subjects

Handong Sun

Publications and source records attributed to Handong Sun.

10 recordsLinked to original sources

PubMed2006

Cytotoxic ent-kaurene diterpenoids from Isodon phyllostachys.

ent-Kaurene diterpenoids, phyllostachysins D-H (1-5), together with nine known compounds, rabdoloxins A-B (6-7), rabdoinflexin B (8), amethystoidin A (9), rabdokunmin D (10), macrocalyxin E (11), 5,7-dihydroxy-4'-hydroxylflavone (12), oleanolic acid (13) and daucosterol (14), were isolated from aerial parts of Isodon phyllostachys. Structures were elucidated on the basis of spectroscopic methods, especially using 2D-NMR spectroscopic analyses. All ent-kaurenoids were tested for their cytotoxic effects against K562 cells. Compound 9 was the most potent with an IC50 value of 0.69 microg/ml.

Cell Line, Tumor↗

PubMed2006

Effect of total phenolics from Laggera alata on acute and chronic inflammation models.

The anti-inflammatory effect of total phenolics from Laggera alata (TPLA) was evaluated with various in vivo models of both acute and chronic inflammations. In the acute inflammation tests, TPLA inhibited significantly xylene-induced mouse ear oedema, carrageenan-induced rat paw oedema and acetic acid-induced mouse vascular permeability. In the carrageenan-induced rat pleurisy model, TPLA significantly suppressed inflammatory exudate and leukocyte migration, reduced the serum levels of lysozyme (LZM) and malondialdehyde (MDA), increased the serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and also decreased the contents of total protein, nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in the pleural exudates. In the chronic inflammation experiment, TPLA inhibited significantly cotton pellet-induced rat granuloma. These results indicated that TPLA possesses potent anti-inflammatory activity on acute and chronic inflammation models. Its anti-inflammatory mechanisms are probably associated with the inhibition of prostaglandin formation, the influence on the antioxidant systems, and the suppression of LZM release. Furthermore, the total phenolic content of Laggera alata and its main component type was quantified, and its principle components were isolated and authenticated. Acute toxicity studies revealed that TPLA up to an oral dose of 8.5 g/kg body weight was almost nontoxic in mice.

Acute Disease↗

PubMed2006

Evaluation of antiinflammatory activity of the total flavonoids of Laggera pterodonta on acute and chronic inflammation models.

The antiinflammatory effect of the total flavonoids of Laggera pterodonta (TFLP) was evaluated with various in vivo models of both acute and chronic inflammation. In the acute inflammation tests, TFLP significantly inhibited xylene-induced mouse ear oedema, carrageenan-induced rat paw oedema and acetic acid-induced mouse vascular permeability. In the carrageenan-induced rat pleurisy model, TFLP efficiently suppressed inflammatory exudate and leukocyte migration, reduced the serum levels of lysozyme (LZM) and malondialdehyde (MDA), increased the activity of serum superoxide dismutase (SOD), and also decreased the contents of total protein, nitric oxide (NO) and prostaglandin E2 (PGE2) in the pleural exudates. No marked effect of TFLP on the activity of serum glutathione peroxidase (GSH-PX) was observed. In the chronic inflammation experiment, TFLP inhibited cotton pellet-induced rat granuloma. The antiinflammatory mechanisms of TFLP are probably associated with the inhibition of prostaglandin formation, influence on the antioxidant systems and the suppression of LZM release. The acute toxicity study revealed that TFLP was nontoxic in mice up to an oral dose of 7.5 g/kg body weight.

Acute Disease↗

PubMed2005

Antioxidant properties of two gallotannins isolated from the leaves of Pistacia weinmannifolia.

Pistacia weinmannifolia J. Poisson ex Franch (Anacardiaceae) is a shrub or arbor widely found in Yunnan province of China and its leaves are used as traditional Chinese medicine by herbalists. The leaves of P. weinmannifolia are rich in phenolic compounds, among which two novel gallotannins, Pistafolin A and Pistafolin B, are identified. In the present investigation, the antioxidant efficiency of Pistafolin A and Pistafolin B in preventing lipid, protein and DNA from reactive oxygen species-mediated damage was studied. Both Pistafolin A and Pistafolin B inhibited the peroxyl-radical induced lipid peroxidation of l-alpha-phosphatidylcholine liposomes dose-dependently and prevented the bovine serum albumin from peroxyl-induced oxidative damage. Pistafolin A and Pistafolin B also inhibited copper (II)-1,10-phenanthroline complex-induced DNA oxidative damage. Both Pistafolin A and Pistafolin B scavenged the hydrophilic 2,2'-azinobis(3-ethylbenzothiozoline-6-sulphonic acid) diammonium salt-free radicals and the hydrophobic 1,1-dipheny-2-picrylhydrazyl radicals effectively, suggesting they may act as hydrogen donating antioxidants. The protective effects of the two gallotannins against oxidative damage of biomacromolecules were due to their strong free radical scavenging ability. Pistafolin A with three galloyl moieties showed stronger antioxidant ability than Pistafolin B with two galloyl moieties.

Antioxidants↗

PubMed2004

A novel cytotoxic oxetane ent-kauranoid from Isodon japonicus.

A novel ll,20: 1,20-diepoxy-ent-kaurane diterpenoid, maoyecrystal 1 (1), was isolated from Isodan japonicus, and its structure was elucidated by spectroscopic methods and comparison with another new ent-kauranoid, rubescensin W (2) from Isodon rubescens var. taihangensis. The structure of 2 was determined by single crystal X-ray diffraction analysis. A bioassay of their cytotoxity against K562 cells showed that the oxetane group of 1 might be a bioactive moiety.

Antineoplastic Agents, Phytogenic↗

PubMed2003

Eudesmane and megastigmane glucosides from Laggera alata.

Four eudesmane glucosides, alatosides A-D (1-4), and one megastigmane glucoside, alatoside E (5), were isolated from the BuOH fraction of Laggera alata along with six known compounds. Structures of the new compounds were elucidated by a combination of chemical and spectroscopic methods. Alatosides A-E were characterized as: 1alpha-O-(beta-D-glucopyranosyloxyl)-7-epi-eudesma-11-en-2beta,4alpha-diol (1), 2beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4alpha-hydroxyl-11(13)-en-12-oic-acid (2), 5beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4(15),11(13)-dien-12-oic-acid (3), 5alpha-O-(beta-D-glucopyranosyloxyl)-eudesma-3,11(13)-dien-12-oic acid (4) and 3beta-O-(beta-D-glucopyranosyloxyl)-megastigma-9-one (5), respectively. Based on the chemical characteristics of eudesmane derivatives isolated from the Laggera genus, it was suggested that there are probably two different biogenetic pathways for these secondary metabolites in this genus.

Asteraceae↗

PubMed2003

Eudesmane derivatives from Laggera pterodonta.

A new eudesmane derivative, 4alpha,5alpha-dihydroxyeudesma-11(13)-en-12-oic acid, was isolated from Laggera pterodonta. Its structure was elucidated as (1) on the basis of spectroscopic evidence. Moreover, six known compounds were isolated: pterodontriol A (2), pterodontriol B, pterodonta acid (3), ilicic acid (4), costic acid and beta-amyrin. Cytotoxic activity of compounds 2, 3 and 4 was investigated.

Antineoplastic Agents↗

PubMed2002

Scavenging of reactive oxygen species and prevention of oxidative neuronal cell damage by a novel gallotannin, pistafolia A.

Pistafolia A is a novel gallotannin isolated from the leaf extract of Pistacia weinmannifolia. In the present investigation, the ability of Pistafolia A to scavenge reactive oxygen species including hydroxyl radicals and superoxide anion was measured by ESR spin trapping technique. The inhibition effect on iron-induced lipid peroxidaiton in liposomes was studied. The protective effects of Pistafolia A against oxidative neuronal cell damage and apoptosis induced by peroxynitrite were also assessed. The results showed that Pistafolia A could scavenge both hydroxyl radicals and superoxide anion dose-dependently and inhibit lipid peroxidation effectively. In cerebellar granule cells pretreated with Pistafolia A, peroxynitrite-induced oxidative neuronal damage and apoptosis were prevented markedly. The antioxidant capacity of Pistafolia A was much more potent then that of the water-soluble analog of vitamin E, Trolox. The results suggested that Pistafolia A might be used as an effective natural antioxidant for the prevention and cure of neuronal diseases associated with the production of peroxynitrite and related reactive oxygen species.

Animals↗

PubMed2002

Structure of a novel diterpenoid ester, fritillahupehin from bulbs of Fritillaria hupehensis Hsiao and K.C. Hsia.

A new diterpenoid ester, fritillahupehin (1) together with three known fatty acids: palmitic acid (2), lignoceric acid (3) and azelaic acid (4) were isolated from the bulbs of Fritillaria hupehensis Hsiao and K.C. Hsia. The structure of fritillahupehin has been established to be ent-kauran-16beta-yl lignocerate by means of spectroscopic and chemical evidence. Compounds 2-4 were isolated from Fritillaria sp. for the first time.

Dicarboxylic Acids↗

PubMed2002

Pseudoirroratin A, a new cytotoxic ent-kaurene diterpene from Isodon pseudo-irrorata.

A new ent-kaurene diterpene, pseudoirroratin A (1), and a known diterpene, pseurata A, were isolated from Isodon pseudo-irrorata. Compound 1 showed significant cytotoxicity against the Lu1, SW626, LNCaP, KB, and HOS cancer cell lines with IC(50) values of 0.26 (0.75), 0.20 (0.57), 0.90 (2.59), 0.90 (2.59), and 0.50 (1.44) microg/mL (microM), respectively. The structure of 1 was elucidated by spectroscopic means including 1D and 2D NMR techniques.

Antineoplastic Agents, Phytogenic↗