The interaction of drug and target protein is a critical part of new drug discovery. It is the premise for drugs to exert therapeutic effects by targeting specific binding sites of target proteins and thereby affecting its pharmacological activity. Currently, a variety of techniques are exploited to detect the interaction between drug ligands and target proteins. For example, cellular thermal shift assay (CETSA) and differential scanning fluorimetry (DSF) based on thermodynamics, mass spectrometry and nuclear magnetic resonance technology, etc. In addition, high-throughput ligand screening technology provides technical convenience for the search of specific ligand, and is a powerful tool to efficiently identify the interaction between drug ligand and target protein. Here, we summarize the detection techniques of interaction between small molecules and target proteins, and discuss the application of high-throughput ligand screening technology in drug research.

Target identification and verification of natural products is an important and challenging work in the field of chemical biology. It is also an important job for researchers to apply chemical proteomics technology to biomedicine in order to identify target proteins of natural products. Target identification is critical to understanding its mechanisms and developing natural products as molecular probes and potential therapeutic drugs. Traditional approaches of small molecule target identification based on affinity have been shown to be successful, such as click-chemical probes, radioisotope labeling or photosensitized small-molecule probes. Nevertheless, these technologies require purified candidate target proteins, and modified small molecules with probes or linkers, such as adding agarose beads, biotin labels, fluorescent labeling or photo-affinity labeling. Many structure-activity relationship studies should be performed to ensure that the addition of small molecule labels undisturbed the original biological activity of the small molecules. Unfortunately, all these modifications are likely to alter their biological activity or binding specificity. To overcome the bottleneck of "target recognition", researchers have developed a series of new techniques for unmodified drug target identification. In this article, we reviewed the target identification techniques of natural product without structural modification in order to provide reference for the development of natural products.

Taxus canadensis distributed mainly in North America, such as northern Minnesota, Newfoundland, south to Wisconsin and Pennsylvania. Its composition has been shown to be very different from other species, and in recent years, some new skeletons also have been found in Canada yew. Through analysis of the taxanes content on various Taxus plants containing taxanes, the results showed a higher content of taxol in T. canadensis. Based on the current research on T. canadensis (from the research results of the author in recent years, as well as from studies of scholars in the field), the paper outlined the research progress in recent years on the chemical constituents of taxane of T. canadensis and the spectral characteristics of various types of compounds. Besides, this paper analyzed the present research about solutions for the taxol drug source crisis.
Animals ; Bridged-Ring Compounds ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Molecular Structure ; Plant Extracts ; chemical synthesis ; chemistry ; pharmacology ; Plants, Medicinal ; chemistry ; Taxoids ; chemical synthesis ; chemistry ; pharmacology ; Taxus ; chemistry

Objective To summarise the perioperative features of orthotopic liver transplantations(OLTs) in miniature porcine,to establish mature、stable OLT models.Methods In order to observe hemodynamics and blood changes and improved perioperative management and summarise the perioperative characteristics,8 preliminary experiments(group A) and 18 experiments(group B) of OLTs were performed without veno-venous bypass(VVB) in Chinese inbred miniature porcine.Results The mean operation time was(179.6?14.3)min in our 18 OLTs,and the mean anhepatic phase time was(27.3?3.4)min.Dramatic hemodynamic and metabolic changes were identified during anhepatic phase.The oneweek survival rate was 88.9% in group B,but all the 8 pigs in group A died.The experiment group pigs urinated after 3～5hours and had normal diet after 3days.Conclusions Decreasing the operation time and stability of hemodynamics in anhepatic phase are the keys for success in OLTs without VVB.

OBJECTIVETo study the flavone constituents in Chrozophora sabulosa (Xinjiang origin).

METHODThe compounds were extracted with 95% ethyl alcohol, isolated by various column chromatography and identified by spectroscopic methods.

RESULTSeven flavanoids were isolated and identified as quercetin (I), kaempferol (II), apigenin (III), chrysoerid (IV), isoquercitrin (V), chrysoerin-7-O-beta-D-glucoside (VI) and quercetin-3-O-alpha-D-arabinfuranoside (VII).

CONCLUSIONAll of these seven compounds were obtained from this genus for the first time.

Apigenin ; chemistry ; isolation & purification ; Euphorbiaceae ; chemistry ; Flavones ; chemistry ; isolation & purification ; Kaempferols ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Quercetin ; chemistry ; isolation & purification

OBJECTIVETo investigate the flavonoid constituents of Ipomoea batatas.

METHODThe leaf was extracted with EtOH and partitioned with CHCl3, EtOAc and n-BuOH respectively. The chemical components of EtOAc fraction were isolated by silica gel and sephadex LH-20 column chromatography. The chemical structures were elucidated on the basis of physic-chemical properties and spectral data.

RESULTFive compounds were isolated and identified as: tiliroside (I), astragalin (II), rhamnocitrin (III), rhamnetin (IV) and kaempferol (V).

CONCLUSIONAll of these five compounds were obtained from this plant for the first time.

Benzopyrans ; chemistry ; isolation & purification ; Flavonoids ; Ipomoea batatas ; chemistry ; Kaempferols ; chemistry ; isolation & purification ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; analogs & derivatives ; chemistry ; isolation & purification

OBJECTIVETo study the chemical constituents in root of Coleusforskohlii.

METHODThe chemical constituents were isolated by column chromatography. The structures were elucidated on the basis of IR, MS, 1H-NMR, 13C-NMR and 2D-NMR experiments.

RESULTSix compounds were obtained and the structures were identified as 14-deoxycoleon U (1), demethylcryptojaponol (2), alpha-amyrin (3), betulic acid (4), alpha-cedrol (5) and beta-sitosterol (6).

CONCLUSIONCompounds 1 and 2 were isolated from the genus Coleus for the first time. Compounds 3 and 4 were isolated from C. forskohlii for the first time.

Coleus ; chemistry ; Diterpenes ; chemistry ; isolation & purification ; Oleanolic Acid ; analogs & derivatives ; chemistry ; isolation & purification ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Triterpenes ; chemistry ; isolation & purification

AIMIn order to look for new bioactive compounds, investigation on the chemical constituents, especially on the typical polyacetylenes from the rhizomes of Cirsium japonicum DC. was carried out.

METHODSChromatographic techniques including silica column chromatography and preparative silica thin-layer chromatography were used to separate and purify the constituents. Their structures were elucidated by physicochemical properties and spectral analyses including UV, IR, 1HNMR, 13CNMR, HMQC, HMBC and HREIMS.

RESULTSTwelve compounds were isolated from the rhizomes of Cirsium japonicum DC., and their structures were identified as cis-8, 9-epoxy-heptadeca-1-ene-11, 13-diyne-10-ol (1), ciryneol A (2), 8,9,10-triacetoxyheptadeca-1-ene-11,13-diyne (3), ciryneone F (4), cireneol G (5), ciryneol H (6), ciryneol C (7), p-coumaric acid (8), syringin (9), linarin (10), beta-sitosterol (11) and daucosterol (12).

CONCLUSIONCompounds 4, 5 and 6 are new compounds, compound 3 is a new natural product and compound 8 was isolated from this plant for the first time.

Cirsium ; chemistry ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Molecular Conformation ; Molecular Structure ; Plants, Medicinal ; chemistry ; Rhizome ; chemistry

AIMIn order to look for new active compounds, the structure of (+)-praeruptorin A is modified.

METHODS(+)-Praeruptorin A was isolated from the root of Peucedanum praeruptorum, basic hydrolysis of (+)-praeruptorin A and acyled reactions of hydrolysis product of (+)-praeruptorin A were carried out.

RESULTSEighteen compounds were semi-synthesized from (+)-praeruptorin A.

CONCLUSIONFourteen compounds (5-18) among them are new compounds. Preliminary bioactivity assay indicated that the new compounds show calcium antagonist activity, but they are not as strong as (+)-praeruptorin A.

Animals ; Aorta, Thoracic ; drug effects ; Apiaceae ; chemistry ; Calcium Channel Blockers ; chemical synthesis ; isolation & purification ; pharmacology ; Coumarins ; chemical synthesis ; isolation & purification ; pharmacology ; Drugs, Chinese Herbal ; chemical synthesis ; isolation & purification ; pharmacology ; Molecular Structure ; Muscle Contraction ; drug effects ; Muscle, Smooth, Vascular ; drug effects ; Plants, Medicinal ; chemistry ; Rats

OBJECTIVETo find out the bioactive principles of Alpinia tonkinensis, by investigating its chemical constituents.

METHODIt was extracted with MeOH, distributed by different solvents, and isolated via column chromatography on silica gel.

RESULTSix compounds were elucidated through spectral analysis, which were as follows: 4',7-dimethylkaempferol(I), 5-hydroxy-3',4',7-trimethoxyflavanone(II), kumatakenin(III), 4',5,7-trimethoxyflavonol(IV), ombuine(V), and kaempferol(VI).

CONCLUSIONSix flavonoids were isolated from this plant for the first time, and so were four compounds from genus Alpinia.

Alpinia ; chemistry ; Flavonoids ; chemistry ; isolation & purification ; Kaempferols ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Rhizome ; chemistry