Phenolic constituents from the branches of Viburnum chinshanense as potential α-amylase and α-glucosidase inhibitory agents.

This paper reports the isolation of two undescribed phenolic glycosides (1 and 2), together with seven known compounds (3-9) from the branches of Viburnum chinshanense. The structures of undescribed compounds were elucidated by comprehensive spectroscopic methods (1D NMR, 2D NMR, and HRESIMS). The sugar units of compounds 1 and 2 were identified by acid hydrolysis and HPLC analysis of the chiral derivatives of the monosaccharides. Furthermore, the α­amylase and α-glucosidase inhibitory activities of all isolates were evaluated and compounds 1, 5, and 8 displayed potential α­amylase and α-glucosidase inhibitory activities. The molecular docking analyses of compounds 1 and 8 with the potent inhibition towards the target enzymes were also performed.

Lignan and phenolic glycosides from Viburnum betulifolium fruits and their α­amylase and α-glucosidase inhibitory activities.

The phytochemical investigation on the methanol extract of Viburnum betulifolium fruits resulted in the isolation and identification of two new lignan constituents (1 and 2) and seven known phenolic glycosides (3-9). The structures of new isolates, including their absolute configurations were elucidated by extensive spectroscopic analyses (1H and 13C NMR, HSQC, HMBC, HRESIMS, and ECD) and chemical methods. In the in vitro enzyme assays, compounds 1, 2, 6, and 8 showed potential α­amylase and α-glucosidase inhibitory activities. Among them, compound 1 exhibited stronger inhibitory effects towards α-amylase and α-glucosidase with the IC50 values of 12.68 and 15.17 µM, respectively, than those of the positive control acarbose (IC50, 29.19 and 18.15 µM, respectively). In addition, the molecular docking analyses of compound 1 with strongest inhibition against the target enzymes were also performed.

LC-MS guided isolation of phenolic glycosides from Viburnum luzonicum Rolfe leaves and their α­amylase and α-glucosidase inhibitory activities.

Viburnum luzonicum Rolfe is widely used in China as folk medicine. The bioactivity evaluation indicated that the n-BuOH fraction of V. luzonicum leaves (VLLB) could significantly inhibit α­amylase and α-glucosidase. In order to clarify its active constituents, the phytochemical analysis on VLLB was first performed using HPLC-QTOF-MS/MS, and three new phenolic compounds, viburosides A-C (1-3), along with seven known analogues (4-10) were isolated through preparative HPLC. The undescribed compounds were determined by extensive spectroscopic analyses (1H and 13C NMR, HSQC, HMBC, HRESIMS, and ORD) and enzymatic hydrolysis. In the in vitro enzyme assays, compounds 1-8 showed potent α­amylase and α-glucosidase inhibitory activities. The enzymatic kinetics and molecular docking of the strongest inhibitors 2 and 3 against the corresponding target enzyme were also performed.

Two new phenolic allopyranosides and their analogues from the stems of Viburnum luzonicum Rolfe guided by LC-MS.

Two new phenolic allopyranosides, named viburluzosides A and B (1, 2), together with eight known phenolic glycosides (3 - 10) were discovered from the stems of Viburnum luzonicum Rolfe under the guidance of LC-MS analyses coupled with bioactivity evaluation. They were purified through various chromatography methods and identified by extensive spectroscopic analyses (1H and 13C NMR, HSQC, HMBC, and HRESIMS) and chemical methods. The in vitro evaluation on α-glucosidase and aldose reductase (AR) inhibitory activities of isolated compounds were conducted. Compounds 1 - 4 and 6 - 9 exhibited α-glucosidase inhibitory activities with IC50 values of 5.35 - 21.34 µM and AR inhibitory activities with IC50 values of 6.21 - 40.06 µM. Moreover, the inhibitory kinetics analyses of compounds 1 and 2 were also performed.

Recent Advance on Chemistry and Bioactivities of Secondary Metabolites from Viburnum Plants: An Update.

Viburnum species are a group of small trees or shrubs that are of great ornamental and medicinal values. Some of them have been used for a long time both as conventional and ethnic medicine. Viburnum fruits, eaten in fresh and processed forms, have been revealed to contain various health-promoting nutrients. With the increasing research on Viburnum plants, they are considered to be an abundant resource of bioactive natural products possessing diverse pharmacological properties and unique chemical structures, that is powerfully proved by the existence of structurally novel vibsane-type diterpenoids which only occur in Viburnum species, newly discovered lignan constituents with unusual side chains and other noteworthy natural components. This review describes 185 new and 228 known secondary metabolites from Viburnum genus between 2008 and 2020, including their chemical structures, sources and bioactivities, and highlights the corresponding structure-activity relationships.

Lignan Constituents from the Fruits of Viburnum macrocephalum f. keteleeri and Their α-Amylase, α-Glucosidase, and Protein Tyrosine Phosphatase 1B Inhibitory Activities.

Eight previously undescribed lignan glycosides, viburmacrosides A-H (1-8), and seven known analogues (9-15) were isolated from Viburnum macrocephalum f. keteleeri fruits through bioactivity-guided fractionation. Their structures and absolute configurations were elucidated by extensive spectroscopic analyses and chemical evidence. Using the well-recognized carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase, as well as the promising protein tyrosine phosphatase 1B (PTP1B), as inhibitory targets, all isolated compounds were tested for their antidiabetic potential in vitro. Compound 4 displayed potent inhibitory activities with IC50 values of 9.9 ± 0.6 and 8.9 ± 0.5 µM against α-glucosidase and PTP1B, respectively. The enzymatic kinetics results suggested that compound 4 competitively inhibited α-glucosidase while it suppressed α-amylase and PTP1B in the mixed-type manner. These findings supported that V. macrocephalum f. keteleeri fruits may be a new functional food resource with antidiabetic potential.

Chemical constituents and biological activities of Viburnum macrocephalum f. keteleeri.

Three new compounds (1-3) and seven known compounds (4-10) have been isolated from the ethanolic extract of Viburnum macrocephalum f. keteleeri using bioactivity-guided fractionation and identified as methyl (2-α-L-rhamnopyranosyloxy)acetate (1), methyl (2R-3-α-L-rhamnopyranosyloxy)glycerate (2), methyl (3R-4-α-L-rhamnopyranosyloxy-3-hydroxy)butanoate (3), bridelionoside B (4), (6S,7E,9R)-roseoside (5), linarionoside A (6), 3,7,11-trimethyl-1,6-dodecadien-3,10,11-triol (7), (+)-8-hydroxylinalool (8), ß-sitosterol (9) and daucosterol (10). The structures of 1-3, including absolute configurations, were determined by spectroscopic data (1H and 13C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, compounds 1-8 were assayed for their insecticidal and antimicrobial activities. Compounds 7 and 8 exhibited moderately insecticidal effects against Mythimna separata with LD50 values of 180 and 230 µg g-1, respectively. Compounds 2, 3, 7 and 8 showed varying antimicrobial activities with IC50 values ranging from 125 to 529 µM.

Phenolic glycoside constituents from Brassica rapa flowers and their α-glucosidase inhibitory activity.

Two new phenolic glycoside compounds (1, 2) and ten known analogues (3-12) have been isolated from the ethanolic extract of Brassica rapa flowers and identified as 2-O-ß-d-glucopyranosyl-(1S)-(4-methoxyphenyl)ethylene glycol (1), 2-(4-O-ß-d-allopyranosyl)phenyl-ethanol (2), 2-O-ß-d-glucopyranosyl-(1S)-phenylethylene glycol (3), 2-O-ß-d-glucopyranosyl-(1R)-phenylethylene glycol (4), (Z)-p-coumaryl-O-ß-d-glucopyranoside (5), phenyl-O-ß-d-glucopyranoside (6), 2-phenylethyl-O-ß-d-glucopyranoside (7), salidroside (8), 2-(2-hydroxyphenyl)ethanol-O-ß-d-glucopyranoside (9), 4-methoxybenzyl-O-ß-d-glucopyranoside (10), 2,4,6-trimethoxyphenyl-1-O-ß-d-glucopyranoside (11) and sachaliside 1 (12). The structures of 1 and 2, including absolute configurations, were determined by spectroscopic data (1H NMR, 13C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, most of them exhibited inhibitory activity with IC50 values ranging from 14.43 to 50.20 µM in comparison to the positive control acarbose (IC50 = 15.76 µM) in intestinal α-glucosidase inhibitory activity tests.

Insecticidal and α-glucosidase inhibitory activities of chemical constituents from Viburnum fordiae Hance.

The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C13-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-ß-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-ß-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-ß-ionyl 9-O-α-d-arabinopyranosyl-(1→6)-ß-d-glucopyranoside (1) and 2-(4-O-ß-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD50 value of 140 µg g-1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC50 values ranging from 148.2 to 230.9 µM.

[IL-32 mRNA Expression of Bone Marrow Stromal Cells and Its Correlation with Cell Apoptosis in Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the IL-32 mRNA expression of bone marrow stromal cells and its correlation with apoptosis of bone marrow mononuclear cells in patients with myelodysplastic syndrome (MDS). METHODS: Bone marrow samples from 26 MDS patients and 10 iron deficiency anemia (IDA, as control) patients were collected, RT-PCR was used to detect the IL-32 mRNA expression of bone marrow stromal cells, and the apoptosis of bone marrow mononuclear cells was detected by flow cytometry with Annexin V-FITC/PI dowble staining. The born marrow lymphocytes and NK cells were detected by means of direct immunofluorescence labeling whole blood hemolysis and flow cytometry. RESULTS: IL-32 mRNA expression of bone marrow stromal cells in the MDS patients was significantly higher than that of control group, the IL-32 mRNA expression of bone marrow stromal cells in patients with RA, RAS and RCMD was significantly higher than that in patients with RAEB. There was no obvious difference between RAEB and the control groups. The apoptosis of bone marrow mononuclear cells in MDS group was significantly higher than that in the control group, the apoptosis of bone marrow mononuclear cells in patients with RA, RAS and RCMD was significantly higher than that in RAEB. There was no significant difference between RAEB group and control group. The IL-32 mRNA expression in bone marrow stromal cells significantly correlated with the apoptosis of bone marrow mononuclear cells in MDS patients. The NK cell number in born marrow of MDS patients and the control group had no significant difference. CONCLUSION: The expression of IL-32 mRNA in bone marrow stromal cells significantly relates with the apoptosis of MDS cells, and the secretion of IL-32 by bone marrow stromal cells may be one of the reasons for the apoptosis of MDS bone marrow cells. It is speculated that the abnormal MDS bone marrow microenvironment is involved in the apoptosis of bone marrow cells.

Purification, characterization, and bioactivity of a new analgesic-antitumor peptide from Chinese scorpion Buthus martensii Karsch.

Scorpion venoms are complex mixtures of dozens or even hundreds of distinct proteins, many of which have diverse bioactivities. In this study, after bioassay-driven chromatographic purification, a new dual-function peptide with analgesic and antitumor activities was isolated and designated BmK AGAP-SYPU2. The first 12 amino acid residues were sequenced with Edman degradation. The cDNA was cloned by using rapid amplification of cDNA ends from the cDNA pool from scorpion glands. The amino acid sequence of BmK AGAP-SYPU2 was then deduced, and is consistent with the molecular mass measured with MALDI-TOF-MS. A preliminary pharmacological analysis revealed the following: in the dose-effect curve plotted with the mouse-twisting test, BmK AGAP-SYPU2 showed analgesic activity with an ED50 value of 1.42 mg/kg; in the time-effect curves plotted with a hot-plate procedure, BmK AGAP-SYPU2 had similar effects to those of the painkiller morphine, except for its longer duration. BmK AGAP-SYPU2 also showed antitumor activity against Ehrlich ascites tumor and S-180 fibrosarcoma models in vivo. Sequence alignment and homology modeling showed that BmK AGAP-SYPU2 is highly conserved relative to other scorpion α-toxins. However, a few different amino acids endow it with unique molecular properties, which may be responsible for its specific bioactivities. BmK AGAP-SYPU2, a new scorpion neurotoxin with dual functions, is a potential candidate drug amenable to exploitation and modification.

[Mutation detection of mitochondrial DNA D-loop region in bone marrow cells of acute leukemia].

This study was aimed to detect the mutations and microsatellite instability (mtMSI) in mitochondrial DNA (mtDNA) D-loop region in bone marrow cells of acute leukemia (AL) patients, and to analyze their relationship with the pathogenesis of AL. 19 cases of newly diagnosed AL were enrolled in this study. Through extracting mtDNA, the D-loop region was amplified by polymerase chain reaction (PCR), the sequences of PCR products were detected by the pros- and cons-direct sequencing methods. The sequencing results were compared with the revised Cambridge reference sequence (rCRS) and the relevant database (MITOMAP database, GenBank database, mtDB database). The results showed that the mutation rate of mtDNA D-loop region in AL was 79% (15/19). 215 variations (35 mutations, 180 SNP) and a kind of mtMSI in the D-loop region were detected. A new type of mutation nt150 C-CT was found. Also, there was no significant difference in the number of mutations between patients with different ages and different types of AL (AML, B-ALL). It is concluded that there is high frequency of mutations in the mtDNA D-loop, and the mutations may be associated with the pathogenesis of AL.

Oligodeoxyribonucleotides derived from salmon sperm DNA: an alternative to defibrotide.

Defibrotide is a single-stranded nucleic acid polymer originally derived from porcine mucosa. Cheap salmon sperm DNA is commercially available and widely used in drug production. In this study, oligodeoxyribonucleotides were successfully obtained from the controlled depolymerization of salmon sperm DNA. The obtained product shared similar chemical and biological properties with defibrotide produced by Gentium SpA, Italy. It was also found that oligodeoxyribonucleotides derived from non-mammalian origins could also directly stimulate tissue plasminogen activator (t-PA) release from cultured human endothelial cells, and enhance fibrinolytic activity in the rabbit.

[Expression of pituitary tumor transforming gene and C-myc gene in patients with multiple myeloma].

The study was purposed to explore the expressions of pituitary tumor transforming gene and c-myc gene in patients with multiple myeloma (MM) and its relationship with pathogenesis of MM. Expressions of pituitary tumor transforming gene and c-myc gene mRNA in BMMNC from 33 patients with MM and 10 normal controls were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the expressions of pituitary tumor transforming gene and c-myc gene mRNA were significantly higher in MM patients those that in normal controls (p<0.05). The expression of pituitary tumor transforming gene mRNA was significantly correlated with the expression of c-myc gene (r=0.801, p<0.05). In conclusion, the overexpressions of pituitary tumor transforming gene and c-myc gene may be related to the pathogenesis and progression of MM.

[Myocardial expression and distribution of calcineurin in normal and failing human ventricular myocardium].

OBJECTIVE: To explore the expression and distribution of calcineurin (CaN) in normal and failing human myocardium. METHODS: Left and right ventricles were obtained from end-staged heart failure patients (n = 12) undergoing heart transplantation and donor hearts (n = 5) taken from victims of vehicle accidents. Immunohistochemistry and SDS-PAGE technique were used to demonstrate expression and distribution of CaN. RESULTS: Positive immunoreactive staining for CaN was detected in human cardiomyocytes, cardiac fibroblasts and epicardial mesothelial cells, but not detected in cardiac vascular endothelial cells and smooth muscle cells. There was no difference in CaN protein levels between failing hearts and donor hearts (Band intensity of right ventricle in failing hearts and donor hearts was 130.20 +/- 8.66 and 139.87 +/- 6.21, P = 0.33. Band intensity of left ventricle in failing hearts and donor hearts was 106.45 and 126.34 +/- 12.09) and between left ventricular and right ventricular myocardium (Band intensity of left and right ventricles in failing hearts was 96.99 +/- 10.67 and 104.58 +/- 13.18, P = 0.63. Band intensity of left and right ventricles in failing hearts was 132.12 and 120.74). CONCLUSIONS: CaN is expressed in human cardiomyocytes, fibroblasts and epicardial mesothelial cells and the protein level and distribution of CaN are similar in failing and donor hearts.

[Arterial remodeling at the reference site after angioplasty and the effect of granulocyte-macrophage colony-stimulating factor on remodeling].

OBJECTIVE: To observe the correlation of the arterial remodeling at the reference site and the lesion site and the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on arterial remodeling. METHODS: 28 healthy New Zealand White rabbits were randomized to 2 equal groups: GM-CSF group receiving subcutaneous injection of GM-CSF (10 microg x kg(-1)xd(-1)) for 7 days, and pure damage group given subcutaneous injection of equivalent normal saline foe 7 days. Seven days later the iliac arteries of all animals were damaged by balloon. The levels of nitrogen monoxide (NO) were detected before and 4 weeks after angioplasty. Histological sections of iliac from rabbits killed 4 weeks after angioplasty were analyzed. Lumen area (LA), external elastic lamina area (EELA), and intimal plus medial areas (I + M) were measured at the lesion(L) and reference(R) sites. RESULTS: The NO levels 4 weeks later of the GM-CSF group was 98 +/- 10 micromol/L, significantly higher than that of the pure damage group (83 +/- 12 micromol/L, P < 0.05). Morphometric analysis showed that the LA(L) of the pure damage group was (0.87 +/- 0.40) mm2, significantly smaller than that of the GM-CSF group [(1.34 +/- 0.52) mm2, P < 0.05]. The I + M(L) of the pure damage group was (2.62 +/- 0.48) mm2, significantly greater than that of the GM-CSF group [(2.26 +/- 0.43) mm2, P < 0.05]. There was no statistical significance in the EEL(L) between the 2 groups [(3.48 +/- 0.80) mm2 versus (3.60 +/- 0.91) mm2, P > 0.05]. Morphometric analysis showed that the LA(R) of the pure damage group was (1.60 +/- 0.48) mm2, significantly smaller than that of the GM-CSF group [(1.99 +/- 0.54) mm2, P < 0.05], whereas there was no statistical significance in the I + M(R) between the 2 groups. In both groups, LA(R) was significantly correlated with LA(L) (r = 0.919, P < 0.001); and EELA(R) was significantly correlated with EELA(L) (r = 0.909, P < 0.001) and I + M(R) (r = 0.685; P < 0.001). CONCLUSION: Remodeling affects both the lesion and the reference sites and appears to occur in parallel and proportionately at both sites. GM-CSF treatment increases re-endothelialization of the injured artery and inhibits unfavorable remodeling.

Flavonoids from Galium verum L.

Two new flavonoids, compounds 1 and 2, together with seven known flavonoids, were isolated from Galium verum L. Their structures were elucidated as diosmetin 7-O-alpha-l-rhamnopyranosyl-(1-2)-[beta-d-xylopyranosyl-(1-6)]-beta-d-glucopyranoside (1) and 3,5,7,3',4',3'',5'',7'',3''',4'''-decahydroxyl-[8-CH(2)-8'']-biflavone (2) by chemical methods and spectroscopic analyses. Compounds 3 and 4 were isolated from the genus Galium for the first time.

Cloning, expression, and pharmacological activity of BmK AS, an active peptide from scorpion Buthus martensii Karsch.

BmK AS is a beta long-chain scorpion peptide from the venom of Buthus martensii Karsch (BmK). It was efficiently expressed as a soluble and functional peptide in Escherichia coli, and purified by metal chelating chromatography. About 4.2 mg/l purified recombinant BmK AS could be obtained. The recombinant BmK AS maintained a similar analgesic activity to the natural one in both the mouse-twisting test and hot-plate procedure. It also exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. BmK AS is the first long-chain scorpion peptide reported to have antimicrobial activity, and is a valuable molecular scaffold for pharmacological research.

Beneficial effects of losartan on vascular injury induced by advanced glycosylation end products and their receptors in spontaneous hypertension rats.

This study was designed to explore the role of losartan, an angiotensin II receptor blocker, in hypertensive injuries of blood vessels and the potential mechanisms related to the vascular advanced glycosylation end product (AGE)/receptor (RAGE) system, oxidative stress and endothelial proinflammatory factors. Spontaneously hypertensive rats (SHR) were employed for our study, and age-matched Wistar-Kyoto rats (WKY) were used for control experiments. After losartan treatment for 12 weeks, we observed by immunofluorescence that the vascular AGE level in the losartan group was significantly lower than that of the SHR group and that the vascular mRNA expression of RAGE, NF-kappaB, NADPH oxidase p47phox and ET-1, as detected by RT-PCR, was significantly lower in losartan group than in the SHR group. Meanwhile, we found that the expression of RAGE and NF-kappaB proteins in the losartan group and the WKY group was remarkably lower than that of the SHR group. Compared with the SHR group, the activities of plasma superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) and the NO level were robustly increased, while the plasma malondialdehyde (MDA) and ET-1 were substantially reduced. These findings suggest that losartan decreases the vascular AGE level, suppresses RAGE and NF-kappaB activation, and enhances the antioxidant capacity thereby improving the endothelial function, which induce hypertensive vascular remodeling.

[Effects of preconditioning and postconditioning on emergency percutaneous coronary intervention in patients with acute myocardial infarction].

OBJECTIVE: Postconditioning is a novel approach to myocardial protection during ischemia reperfusion. To investigate the effects of preconditioning and postconditioning on coronary blood flow velocity and prognosis of the patients with acute myocardial infarction (AMI) undergoing emergency percutaneous coronary intervention (PCI). METHODS: Ninety-six patients with AMI underwent revascularization by primary PCI within 12 h after the onset. The 35 patients with preinfarction angina were treated with preconditioning (Precond group). The other 61 patients without preinfarction angina were randomized into two groups: 29 patients undergoing PCI without postconditioning [reinfusion (IR) group], and 32 patients undergoing PCI with postconditioning (3 cycles of reinfusion for 30 s/re-occlusion for 30 s beginning within 1 minute after reinfusion, Postcond group). Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was used to evaluate the velocity of coronary blood after PCI. Creatine phosphokinase (CK), CK-MB, and malondialdehyde (MDA) were measured before and after PCI. Wall motion score index (WMSI) was assessed by two-dimensional echocardiography before and 8 weeks after angioplasty. RESULTS: There were no significant differences between the three groups with regard to age, sex, presence of angiographically visible collaterals, and elapsed time from the onset of symptoms until perfusion. The CTFC values of the patients of the Precond and Postcond groups were both 27 +/- 6, 27 +/- 6, both significantly faster than that of the patients of the IR group (31 +/- 7, both P < 0.05). The CK peak values of the Precond and Postcond groups were 1242 U/L +/- 801 U/L and 1237 U/L +/- 813 U/L respectively, both significantly lower than that of the IR group (1697 U/L +/- 966 U/L, P < 0.05). The CK-MB peak values of the Precond and Postcond groups were 122 U/L +/- 78 U/L and 117 U/L +/- 76 U/L respectively, both significantly lower than that of the IR group (172 U/L +/- 93 U/L, P < 0.05). The MDA of the Precond and Postcond groups at all time points were all significantly lower than that of the IR group (all P < 0.05). The WMSI values 8 weeks after PIC of the Precond and Postcond groups were 1.2 +/- 0.2, and 1.2 +/- 0.2 respectively, both significantly lower than that of the IR group (1.4 +/- 0.3, P < 0.05). CONCLUSION: A simple and operative procedure to improve the coronary blood flow velocity and heart function and reduce the production of free oxygen radicals, postconditioning can be used clinically widely so as to better the prognosis of AMI.