Isovanillic acid protects mice against Staphylococcus aureus by targeting vWbp and Coa.

Aim: Our primary objective was to investigate the protective effects and mechanisms of isovanillic acid in mice infected with Staphylococcus aureus Newman. Methods: In vitro coagulation assays were used to validate vWbp and Coa as inhibitory targets of isovanillic acid. The binding mechanism of isovanillic acid to vWbp and Coa was investigated using molecular docking and point mutagenesis. Importantly, a lethal pneumonia mouse model was used to assess the effect of isovanillic acid on survival and pathological injury in mice. Results & Conclusion: Isovanillic acid reduced the virulence of S. aureus by directly binding to inhibit the clotting activity of vWbp and Coa, thereby reducing lung histopathological damage and improving the survival rate in mice with pneumonia.

In Vitro Antithrombotic, Hematological Toxicity, and Inhibitor Studies of Protocatechuic, Isovanillic, and p-Hydroxybenzoic Acids from Maclura tricuspidata (Carr.) Bur.

In blood coagulation, circulating platelets and coagulation factors are crucial for the primary process because thrombi are generated by fibrin clotting with fibrinogen, thrombin, FXIIIa, and platelet activation. Therefore, strategies to reduce the activity of key coagulation factors, or interfere with their functions and delay the activation of platelets can be used as important tools to suppress excessive blood clot formation and platelet hyperactivation. This study examined the antithrombotic activity and hematological toxicity of PA, IVA, and 4-HA isolated from M. tricuspidata (Carr.) Bur in several in vitro experiments and inhibitor assays. We found that PA, IVA, and 4-HA attenuated the formation of fibrin polymers/clots and degraded the blood clots. These compounds inhibited the activities of procoagulant proteases and fibrinoligase, and prolonged the coagulation time. There was a significant reduction in platelet function and ATP or serotonin levels in thrombin-activated platelets. An inhibitor study showed that PA exhibited a mixed inhibition type for thrombin, an uncompetitive inhibition type for FXa, and a non-competitive inhibition type for FXIIIa and IVA, while 4-HA exhibited an uncompetitive inhibition type for thrombin and non-competitive inhibition type for FXa and FXIIIa. These three compounds (up to 50 µg/mL) were not toxic to blood cells.

Studies on chemical constituents of Chloranthus fortunei / 中草药

Objective: To study the antitumor constituents from Chloranthus fortunei. Methods: Various chromatographic techniques and spectroscopic methods were applied to investigate the chemical constituents from C. fortunei, and some of the compounds were screened for their antitumor activities by MTT method. Results: Sixteen compounds were obtained from the whole plants of C. fortunei and identified as rosmarinic acid (1), 2’-hydroxy-4,3’,4’,6’-tetramethoxychalcone (2), flavokawain A (3), cycloshizukaol A (4), atractylenolide III (5), 4β-hydroxy-8,12-epoxyeudesma-7,11-diene-1,6-dione (6), (8α)-6,8-dihydroxycadina-7 (11),10 (15)-dien-12-oic acid γ-lactone (7), curcolonol (8), 11-hydroxyldrim-8,12-en-14-oic acid (9), friedelin (10), isovanillic acid (11), 6β-hydroxystigmast-4-en-3-one (12), 3,4-dihydroxybenzoic acid (13), shikimic acid (14), scopolin (15) and N-acetyltyramine 1-O-β-D-glucoside (16). Compounds 4 and 5 showed weak cytotoxicity with IC50 ranged from 46 to 85 μmol/L. Conclusion: Compounds 2, 10, 11, and 13-15 are obtained from the genus Chloranthus for the first time and compounds 1-3 and 6-16 are isolated from C. fortunei for the first time. Some sesquiterpenoids from C. fortunei exhibited weak antitumor activities.

Structure-affinity relationship of the binding of phenolic acids and their derivatives to bovine serum albumin.

Phenolic acids perform biological effects which are largely influenced by their binding to serum albumin. Therefore, investigating structure-affinity relationship of binding between phenolic acids and serum albumin is important. In this study, 114 phenolic acids and their derivatives, sharing the benzoic acid core with different substituents groups, were selected to investigate structure-affinity relationships with bovine serum albumin. The binding constants were obtained through fluorescence quenching, and a comprehensive mathematical model with inner-filter effect correction was applied. The results showed that the hydroxy group at the 2-position led to stronger binding affinity, while it had a negative influence at the 4-position. Substituting hydroxy groups with methoxy groups at 4-position and with methyl groups at 3-position both strengthened the binding affinity, respectively. Hydrogen bonding was one of the key binding forces for this binding interaction. Our findings provide a fundamental insight on the binding mechanism of phenolic acids to bovine serum albumin.

Chemical constitutes from flesh of Trichosanthes kirilowii / 中草药

Objective: To investigate the chemical constituents from the flesh of Trichosanthes kirilowii. Methods: The chemical constituents from n-butanol fraction of 95% ethanol extract of the flesh of T. kirilowii were separated by silica gel and ODS chromatogram columns as well as preparative HPLC. On the basis of NMR and MS data analysis, their structures were elucidated. Results: Twenty-six compounds were isolated from 95% ethanol extract of T. kirilowii, of which six organic esters were ethyl laurate (1), dibutyl phthalate (2), diethyl ethaneioate (3), dibutyl-2-malate (4), 6,10,14,18-tetramethyl-2-ethyl-7-ene-3-hydroxyl-ninecanol- 1-butyl ester (5), drechslerol-B (6), nine organic acids and phenolic acids were p-hydroxybenzaldehyde (7), salicylic acid (8), vanillic acid (9), isovanillic acid (10), protocatechuate (11), trans-cinnamic acid (12), p-hydroxycinnamic acid (13), trans-ferulic acid (14), and lauric acid (15), eight flavonoids were diosmetin (16), apigenin (17), chrysoeriol (18), luteolin (19), 4’-hydroxyscutellarin (20), quercetin (21), diosmetin-7-O-β-D-glucoside (22), chrysoeriol-7-O-β-D-glucoside (23), two aldehydes were 5-acetoxymethyl- 2-furaldehyde (24), 5-hydroxymethyl furfural (25) and one cycloaltinol compounds was cyclotucanol 3-palmitate (26). Conclusion: All compounds except compound 10 are isolated from the Trichosanthes genus for the first time.

Chemical constituents of Phyllanthus emblica and its anti-inflammation activities / 中草药

Objective: To study the chemical constituents and its anti-inflammtory activity effect of Phyllanthus emblica. Methods: The chemical constituents of P. emblica were isolated and purified by silica gel column chromatography, ODS column chromatography, Sephadex LH-20 column chromatography, semi-preparative high-performance liquid chromatography and recrystallization method. Through their spectra data, physical and chemical properties analysis, the structures of those compounds with high content were identified. LPS-induced RAW264.7 inflammatory cell model was established to evaluate the effect of compounds in P. emblica on proinflammatory factors (NO, IL-6, TNF-α, and MCP-1) of RAW264.7 inflammatory cells. Results: Totally, 14 compounds were isolated from P. emblica. and idetified as isovanillic acid (1), trans-cinnamic acid (2), p-hydroxybenzaldehyde (3), coniferyl aldehyde (4), quercetin (5), kaempferol-3-O-α-L-rhamnose (6), naringenin (7), 2-hydroxy-3-methyl phenylpropiolate (8), hydroquinone (9), myricetin (10), 2-furoic acid (11), methyl gallate (12), protocatechuic acid (13), gallic acid (14). The experiment of anti-inflammatroy effects showed that those compounds had different inhibitory effects on the production of inflammatory factors NO, IL-6, TNF-α and MCP-1. Conclusion: Compounds 1, 3, 4, 8-11 and 13 are isolated from P emblica for the first time. The anti-inflammatory effect of P. emblica is related to its phenolic acids.

Interaction of phenolic acids and their derivatives with human serum albumin: Structure-affinity relationships and effects on antioxidant activity.

In this study, 111 phenolic acids and their derivatives were chosen to investigate their structure-affinity relationships when binding to human serum albumin (HSA), and effects on their antioxidant activity. A comprehensive mathematical model was employed to calculate the binding constants, using a fluorescence quenching method, and this was corrected for the inner-filter effect to improve accuracy. We found that a hydroxy group at the 2-position of the benzene ring exerted a positive effect on the affinities, while a 4-hydroxy substituent had a negative influence. Both methylation of the hydroxy groups and replacing the hydroxy groups with methyl groups at the 3- and 4-positions of the benzene ring enhanced the binding affinities. Hydrophobic force and hydrogen bonding were binding forces for the phenolic acids, and their methyl esters, respectively. The antioxidant activity of the HSA-phenolic acid interaction compounds was higher than that of the phenolic acids alone.

Structure-affinity relationship of the interaction between phenolic acids and their derivatives and ß-lactoglobulin and effect on antioxidant activity.

In this study, 71 phenolic acids and their derivatives were used to investigate the structure-affinity relationship of ß-lactoglobulin binding, and the effect of this interaction on antioxidant activity. Based on a fluorescence quenching method, an improved mathematical model was adopted to calculate the binding constants, with a correction for the inner-filter effect. Hydroxylation at the 3-position increased the affinity of the phenolic acids for ß-lactoglobulin, while hydroxylation at the 2- or 4-positions had a negative effect. Complete methylation of all hydroxy groups, except at the 3-position, enhanced the binding affinity. Replacing the hydroxy groups with methyl groups at the 2-position also had a positive effect. Hydrogen bonding was one of the binding forces for the interaction. The antioxidant activity of phenolic acid-ß-lactoglobulin complexes was higher than that of phenolic acids alone. These findings provide an understanding of the structure-activity relationship of the interaction between ß-lactoglobulin and phenolic acids.

Research on chemical constituents from Reduning Injection (IV) / 中草药

Objective: To study the antipyretic and anti-inflammatory constituents from the active fraction of Reduning Injection (RI). Methods: The active fraction of RI was screened by the LPS-induced mouse endotoxin shock model. The chemical constituents were isolated by chromatography on silica gel, ODS, Sephadex LH-20, Toyopearl HW-40 columns, reverse phase MPLC, and HPLC repeatedly, and their structures were identified by spectral data and physicochemical property. Results: The 95% ethanol eluate of RI on the macroporous adsorption resin column was proved to be the antipyretic and anti-inflammatory active fraction of RI. Fourteen compounds were isolated and identified as dibutyl phthalate (1), isovanillic acid (2), acetovanillone (3), phenylpropionic acid (4), geniposide (5), jasmigeniposide B (6), geniposidic acid (7), genipin-1-β-D-gentiobioside (8), 6″-O-trans-p-coumaroylgenipin gentiobioside (9), 6″-O-trans-feruloylgenipin gentiobioside (10), 6″-O-trans-sinapoylgenipin gentiobioside (11), jasmigeniposide A (12), 6″-O-trans-cinnamoylgenipin gentiobioside (13), and 2'-O-trans-caffeoylgardoside (14). Conclusion: Compounds 1-4 and 13 are reported from RI for the first time; And UPLC analyses and literature data showe that compounds 5 and 7-13 are originated from Gardenia jasminoides.

Chemical constituents in ethyl acetate extract from aerial part of Gynura divaricata / 中草药

Objective: To study the chemical constituents of ethyl acetate fraction in 80% ethanol reflux extract from the aerial part of Gynura divaricata. Methods: Column chromatographic techniques were applied to isolate and purify the chemical constituents. The chemical structures of the constituents were elucidated on the basis of mass properties and NMR spectral data. Results: Fourteen compounds were isolated and their structures were determined spectroscopically as succinic acid (1), methyl succinate (2), ethyl succinate (3), ethyl methyl succinate (4), 4-hydroxybenzoic acid (5), salicylic acid (6), isovanillic acid (7), p-coumaric acid (8), esculetin (9), quercetin (10), kaempferol (11), isoquercitrin (12), astragalin (13), and rutin (14). Conclusion: Compounds 1-4 and 6-9 are isolated from this plant for the first time.

Nonflavonoid constituents from leaves of Apocynum venetum / 中草药

Objective: To study the nonflavonoid constituents in the leaves of Apocynum venetum, the medicinal halophyte. Methods: The constituents were isolated and purified by silica gel and Sephadex LH-20 column chromatography as well as preparative HPLC, and their structures were elucidated by means of physicochemical properties and spectrosocpic analyses. Results: Fifteen nonflavonoid compounds were isolated from the methanol extract from the leaves of A. venetum, and identified as scopoletin (1), esculetin (2), methyl chlorogenate (3), chlorogenic acid (4), grasshopper ketone (5), benzyl-O-β-D-glucopyranoside (6), 2-phenylethyl-O-β-D-glucopyranoside (7), 1-β-O-benzoyl-D-glucopyranoside (8), tyrosol (9), isovanillic acid (10), vanillic acid (11), protocatechuic acid (12), lupeol (13), β-amyrin (14), and α-linolenic acid (15). Conclusion: Compounds 2, 3, 5-10, 14, and 15 are isolated from this plant and the plants in Apocynum Linn. for the first time.