Nitric oxide production inhibitory activity of flavonoids contained in trunk exudates of Dalbergia sissoo

Polyphenolic Contents, Free Radical Scavenging and Cholinesterase Inhibitory Activities of Dalbergiella welwitschii Leaf Extracts

A decoction of Dalbergiella welwitschii leaves has been used ethnomedicinally for the treatment of mental illness and inflammatory diseases amongst other diseases. In this study, the leaf methanol extract of D. welwitschii and its partition fractions: n-hexane, ethyl acetate and aqueous, were tested and evaluated for their polyphenolic contents, free radical scavenging and cholinesterase inhibitory activities. The total phenolic (TPC), flavonoid (TFC) and proanthocyanidin (TPA) contents were determined using standard colorimetric methods. The anti-radical activity of the extracts against the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion and nitric oxide (NO) radicals as well as their effects on lipid peroxidation were monitored spectrophotometrically. The cholinesterase enzyme (AChE and BuChE) inhibitions by the extracts were determined by a modified method of Ellman. The result showed a concentration-dependent increase in inhibition of the free radicals and the cholinesterase enzymes, except for that of lipid peroxidation. The ethyl acetate (EtOAc) fraction exhibited the highest polyphenolic contents among the fractions, with a TPC of 1.08 mgGAE/g, TFC of 0.38 mgQuE/g and TPA of 0.21 mgGAE/g. It also demonstrated the highest free radical scavenging activities with 72.63% and 65.43% inhibitions of DPPH and NO, respectively. The EtOAc fraction inhibited AChE and BuChE enzymes with IC₅₀ values of 0.94 and 8.49 mg/mL, respectively. Our findings show that the plant may have polyphenol contents, in particular in the methanol extract and EtOAc fraction. These extracts showed considerable free radical scavenging and cholinesterase inhibitory properties. Thus, the observed bioactivities may serve as a justification for its folkloric use as a remedy for mental illness. The study also provides relevant information that could help in the search for lead cholinesterase inhibitors from medicinal plants that can be exploited against neurodegenerative disorders.

Dalbergiones lower the inflammatory response in oral cells in vitro

Objectives

Periodontitis is a global health burden that underlines the demand for anti-inflammatory treatment. Dalbergia melanoxylon being a rich source of flavonoids has been widely used in traditional medicine but the potential anti-inflammatory activity of its dalbergiones remains to be shown.

Material and methods

We have isolated 3′-hydroxy-4,4′-dimethoxydalbergione, 4-methoxydalbergione, and 4′-hydroxy-4-methoxydalbergione from Dalbergia melanoxylon and tested their potential anti-inflammatory activity.

Results

All dalbergiones are potent inhibitors of an LPS-induced inflammatory response of RAW 264.7 macrophages. This is specified by IL1β and IL6 production, and the p65 nuclear translocation. Consistently, in primary macrophages, the dalbergiones caused an M1-to-M2 polarization switch indicated by the decreased ration of IL1β and IL6 versus arginase 1 and YM1 expression. To implement oral cells, we have used gingival fibroblasts exposed to IL1β and TNFα. Consistently, all dalbergiones reduced the expression of IL6 and IL8 as well as the nuclear translocation of p65.

Conclusion

These findings increase the accumulating knowledge on dalbergiones and extend it towards its capacity to lower the inflammatory response of oral cells.

Clinical relevance

These findings are another piece of evidence that supports the use of herbal medicine to potentially lower inflammatory events related to dentistry.

Siamese, Indian, and Brazilian Rosewoods: A Review on Phytochemistry, Applications, and Pharmacology

For the first time, the current review fully provides information on the phytochemicals, applications, and pharmacological aspects relating to 3 Dalbergia species, Siamese Rosewood ( Dalbergia cochinchinensis Pierre ex Laness.), Indian Rosewood ( D sissoo Roxb.), and Brazilian Rosewood ( D nigra (Vell.) Benth.). Based on chromatographic separation, phytochemical studies on these plants have, to date, resulted in the isolation and structural elucidation of 136 secondary metabolites. Among them, flavonoids and simple phenols are major components, whereas terpenoids, quinones, benzofurans, benzophenols, phytosterols, stilbenes, phthalates, xanthones, and lignans have been also detected. Dalbergia rosewoods are heavy and strong, taking an outstanding polish, and are very suitable for furniture. They are also used as natural dyes, raw materials for removing contaminants from water, and might be a rich resource of essential oils, polysaccharides, and active glycosidase enzymes. Dalbergia crude extracts and their secondary metabolites have a wide range of pharmacological actions, such as anti-inflammatory, anti-oxidative, anti-aging, anti-bacterial, anti-nociceptive, anti-diarrheal, anti-pyretic, gastrointestinal, biocontrol activities, but sexual and anti-osteoporosis activities are the most valuable.

Two new isoflavones from the barks of Dalbergia hancei Benth

Two new isoflavone compounds, Dalhancei A (1) and Dalhancei B (2), along with a known compound epicatechin (3) were isolated from 80% methanol extract of the barks of Dalbergia hancei Benth. The structures of compounds 1-3 were elucidated by comparison with the literature and physical data analysis, including optical rotation, MS, 1D and 2D NMR spectra. Compounds 1 and 2 showed weak inhibitory activity against tyrosinase at 16.22 mmol/L, with inhibition rates of 42.23 ± 0.18% and 45.68 ± 0.17%, respectively; compound 1 exhibited weak inhibitory activity against α-glucosidase with the inhibition rate of 43.72 ± 0.22% at 5.41 mmol/L, compounds 2 and 3 had better α-glucosidase inhibitory activity than compound 1 with IC₅₀ values of 0.90 ± 0.18 and 0.41 ± 0.17 mmol/L, respectively.

Rapid identification model based on decision tree algorithm coupling with 1H NMR and feature analysis by UHPLC-QTOFMS spectrometry for sandalwood

Sandalwood is one of the most valuable woods in the world. However, today's counterfeits are widespread, it is difficult to distinguish authenticity. In this paper, similar genus (Dalbergia and Pterocarpus) and confused species (Gluta sp.) of sandalwood were quickly and efficiently identified. Rapid identification model based on ¹H NMR and decision tree (DT) algorithm was firstly developed for the identification of sandalwood, and the accuracy was improved by introducing the AdaBoost algorithm. The accuracy of the final model was above 95%. And the feature components between different species of sandalwood were further explored using UHPLC-QTOFMS and NMR spectrometry. The results showed that 183 compounds were identified, among which 99 were known components, 84 were unknown components. The ¹H NMR and ¹³C NMR signals of 505 samples were assigned, among them, 14 compounds were attributed, characteristic chemical shift intervals with great differences in the model were analysed. Furthermore, the fragmentation pattern of different compounds from sandalwood, in both positive and negative ion ESI modes, was summarized. The results showed a potential and rapid tool based on DT, NMR spectroscopy and UHPLC-QTOFMS, which had performed great potential for rapid identification and feature analysis of sandalwood.

Two new compounds from the heartwood of Dalbergia melanoxylon

A new neoflavonoid, named S(+)-3'-hydroxy-4',2,4,5-tetramethoxydalbergiquinol (1), and a new benzofuran, named (2S,3S)-5-hydroxy-6-methoxy-3-methyl-2-(4'-hydroxyphenyl)-2,3dihydrobenzofuran (4), together with two known neoflavonoids, were isolated from the heartwood of Dalbergia melanoxylon. Their structures were elucidated by a combination of spectroscopic methods and comparison with the literature. Compounds 1-4 were evaluated for inhibitory activity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 6538, Salmonella enteri CMCC 50041 and Candida albicans ATCC 289065, which all exhibited inactive or weak activity.

Antimicrobial activity of Apis mellifera L. and Trigona sp. propolis from Nepal and its phytochemical analysis

In this study, we evaluated antimicrobial activity, antimicrobial activity in combination with antibiotics, and chemical composition of Nepalese propolis 70% ethanolic extracts. Propolis originated from two genera of bees - Apis mellifera L. and Trigona sp. HPLC-DAD-MS/MS analyses revealed that the composition of both extracts was almost the same and the main components were flavonoid aglycones (mainly neoflavonoids, isoflavonoids) and pterocarpans. The highest antibacterial activity (disc diffusion test) was observed against Helicobacter pylori, Staphylococcus aureus and Shigella flexneri. Antibiotics exhibited synergism with Apis mellifera L. and Trigona sp. propolis against S. aureus and the strongest effect was observed for the combination with amikacin and tetracycline. Moreover, Nepalase propolis inhibited filamentation of C. albicans and caused oxidative stress by production of the superoxide anion radical (O₂^-) and a lower concentration of the hydroxyl radical (OH). Propolis extracts are potent antibacterial agents and may be used in combination with antibiotics.

Leishmanicidal phenolic compounds derived from Dalbergia cultrata

Leishmaniasis is a protozoan tropical infection that is estimated to be more than 0.3 million new cases occur annually worldwide. A novel phenolic compound, cultratin A (1), was isolated as a leishmanicidal constituent from the timber of Dalbergia cultrata, along with three known neoflavanoids (2, 3, 4), two benzofurans (5, 6), and two phenolic compounds (7, 8). Their structures were determined using spectral methods. Among them, a new compound (1) and 4-(S)-methoxydalbergione (2) showed effective leishmanicidal activities (IC₅₀: 2.0 and 2.6 μM, respectively), while compound 8 showed moderate activity (IC₅₀: 11 μM). The cytotoxicity of compounds 1 and 2 was also weaker than that of the other compounds.

Development, Physicochemical Characterization and In Vitro Anti-Inflammatory Activity of Solid Dispersions of α,β Amyrin Isolated from Protium Oilresin

α,β Amyrin (ABAM) is a natural mixture of pentacyclic triterpenes that has shown a variety of pharmacological properties, including anti-inflammatory effect. ABAM is isolated from Burseraceae oilresins, especially from the Protium species, which is commonly found in the Brazilian Amazon. This work aimed to develop solid dispersions (SD) of ABAM with the following hydrophilic polymers: polyvinylpyrrolidone (PVP-K30), polyethylene glycol (PEG-6000) and hydroxypropylmethylcellulose (HPMC). The SDs were prepared by physical mixture (PM), kneading (KND) and rotary evaporation (RE) methods. In order to verify any interaction between ABAM and the hydrophilic polymers, physicochemical characterization was performed by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis. Furthermore, an in vitro anti-inflammatory assay was performed with ABAM alone and as SDs with the hydrophilic polymers. The results from the characterization analysis show that the SDs were able to induce changes in the physicochemical properties of ABAM, which suggests interaction with the polymer matrix. In vitro anti-inflammatory assay showed that the SDs improved the anti-inflammatory activity of ABAM and showed no cytotoxicity. In conclusion, this study showed the potential use of SDs as an efficient tool for improving the stability and anti-inflammatory activity of ABAM without cytotoxicity.

Zinc-mediated α-regioselective Barbier-type cinnamylation reactions of aldehydes, ketones and esters

We report a simple, efficient, and general method for the zinc-mediated regioselective cinnamylation of aldehydes and ketones under Barbier-type conditions in a one-pot synthesis affording the corresponding α-cinnamylated alcohols in moderate to excellent yields. Compared to the literature procedures, this approach is operationally simple, uses simple reactants, and provides direct access to linear α-cinnamylated alcohols with excellent regioselectivity. Experimental results suggest that the reactions proceed through the radical pathway. In addition, the reaction was found to be scalable to the gram-scale and the one-pot protocol is also applicable to less reactive esters leading to bishomoallylic alcohols which were valuable intermediates for desymmetrizing intramolecular Heck cyclization, allowing for the elaboration to functionalized building blocks.

Transcriptome-enabled discovery and functional characterization of enzymes related to (2S)-pinocembrin biosynthesis from Ornithogalum caudatum and their application for metabolic engineering

Background

(2S)-Pinocembrin is a chiral flavanone with versatile pharmacological and biological activities. Its health-promoting effects have spurred on research effects on the microbial production of (2S)-pinocembrin. However, an often-overlooked salient feature in the analysis of microbial (2S)-pinocembrin is its chirality.

Results

Here, we presented a full characterization of absolute configuration of microbial (2S)-pinocembrin from engineered Escherichia coli. Specifically, a transcriptome-wide search for genes related to (2S)-pinocembrin biosynthesis from Ornithogalum caudatum, a plant rich in flavonoids, was first performed in the present study. A total of 104,180 unigenes were finally generated with an average length of 520 bp. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway mapping assigned 26 unigenes, representing three enzyme families of 4-coumarate:coenzyme A ligase (4CL), chalcone synthase (CHS) and chalcone isomerase(CHI), onto (2S)-pinocembrin biosynthetic pathway. A total of seven, three and one full-length candidates encoding 4CL, CHS and CHI were then verified by reverse transcription polymerase chain reaction, respectively. These candidates were screened by functional expression in E. coli individual or coupled multienzyme reaction systems based on metabolic engineering processes. Oc4CL1, OcCHS2 and OcCHI were identified to be bona fide genes encoding respective pathway enzymes of (2S)-pinocembrin biosynthesis. Then Oc4CL1, OcCHS2 and MsCHI from Medicago sativa, assembled as artificial gene clusters in different organizations, were used for fermentation production of (2S)-pinocembrin in E. coli. The absolute configuration of the resulting microbial pinocembrin at C-2 was assigned to be 2S-configured by combination of retention time, UV spectrum, LC–MS, NMR, optical rotation and circular dichroism spectroscopy. Improvement of (2S)-pinocembrin titres was then achieved by optimization of gene organizations, using of codon-optimized pathway enzymes and addition of cerulenin for increasing intracellular malonyl CoA pools. Overall, the optimized strain can produce (2S)-pinocembrin of 36.92 ± 4.1 mg/L.

Conclusions

High titre of (2S)-pinocembrin can be obtained from engineered E. coli by an efficient method. The fermentative production of microbial (2S)-pinocembrin in E. coli paved the way for yield improvement and further pharmacological testing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12934-016-0424-8) contains supplementary material, which is available to authorized users.

Immunomodulatory effects of Hedysarum polybotrys extract in mice macrophages, splenocytes and leucopenia

Astragali Radix (Huang-Qi) is a popular herbal medicine commonly used as a constituent in tonic herbal preparations. Hedysarum polybotrys Handel-Mazzetti is one species used of Astragali Radix. In this study, the immunomodulatory properties of H. polybotrys were explored by LPS-activated and SNP-treated RAW 264.7 cells and splenocytes and, daunoblastina-induced leucopenia BALB/c mice. Formononetin was used as the bioactive marker to monitor the quality of the H. polybotrys extracts. H. polybotrys was extracted with hot-water and methanol, and MeOH extract partitioned with H₂O (M-H) and ethyl acetate (M-EA) to yield four different fractions. M-EA had the highest formononetin and total proanthocyanidin content and showed stronger inhibitory effects on the production and expression of NO, PGE₂, iNOS and COX-2 in LPS-activated RAW 264.7 cells and splenocytes than the other fractions. In addition, M-EA significantly stimulated the proliferation of LPS-activated RAW 264.7 cells and splenocytes, enhanced NO radicals scavenging and attenuated NO-induced cytotoxicity. Furthermore, M-EA also significantly increased the rate of recovery of white blood cells level in daunoblastina-induced leucopenia mice. These evidences suggest that this traditional Qi-tonifying herb has potential effects in clinical conditions when immune-enhancing and anti-inflammatory effect is desired.

Phytochemical investigation and evaluation of antinociceptive activity of ethanolic extract of Dalbergia sissoo (Roxb.) bark

The antinociceptive activity of ethanolic extract of the plant bark of Dalbergia sissoo (Roxb.) was investigated using tail flick method on Wistar rats. Three different dose levels (300, 500, and 1000 mg/kg) in 0.5% carboxyl methyl cellulose (CMC) were administered by p.o. route. The antinociceptive activities of the all doses were compared with that of the standard drug asprin (300 mg/kg) administered by p.o. route and the results were found to be significant (P < 0.01). At the above doses, the extract exhibited significant and dose-dependent antinociceptive activity. Phytochemical investigation of the ethanolic extract indicated the presence of carbohydrates, proteins, amino acids, phenolic compounds, and flavanoids. The antinociceptive activity of the bark extract of D. sissoo may be due to the presence of phytochemical constituents such as flavanoids. The acute toxicity study revealed that ethanolic extract was not toxic up to 3000 mg/kg body weight.

Cuban and Brazilian red propolis: botanical origin and comparative analysis by high-performance liquid chromatography-photodiode array detection/electrospray ionization tandem mass spectrometry

Chemical composition of propolis depends on the specificity of the local flora at the site of collection and thus on the geographic and climatic characteristics of this place. This paper describes a comparative analysis of Cuban red propolis (CRP), Brazilian red propolis (BRP), and Dalbergia ecastophyllum exudates (DEE) by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry. The aim of this study was to investigate the overall chemical profile and the botanical origin of red propolis and to suggest similarities and differences between samples collected in different tropical regions. Isoliquiritigenin (1), liquiritigenin and naringenin (2 and 17), isoflavones (3-4 and 16), isoflavans (5-7 and 18), and pterocarpans (8-13) were detected in CRP, BRP, and DEE, whereas polyisoprenylated benzophenones (PPBs) guttiferone E/xanthochymol (14a,b) and oblongifolin A (15) were detected only in BRP. Pigments responsible for the red color of DEE and red propolis were also identified as two C30 isoflavans, the new retusapurpurin B (19) and retusapurpurin A (20). PPBs and pigments were isolated and unambiguously characterized by 1D and 2D NMR analysis. These results show that red propolis samples from different tropical zones have a similar chemical composition. DEE is the main red propolis source, but the presence of PPBs in BRP suggests the contribution of different botanical sources for Brazilian samples. This chemical information is important for quality control of red propolis and its commercial products and for biological study.

Chemical constituents of red Mexican propolis

Chemical investigation of a red-type Mexican propolis sample has led to the isolation of three new compounds, 1-(3',4'-dihydroxy-2'-methoxyphenyl)-3-(phenyl)propane (1), (Z)-1-(2'-methoxy-4',5'-dihydroxyphenyl)-2-(3-phenyl)propene (2) and 3-hydroxy-5,6-dimethoxyflavan (3), together with seven known flavanones, isoflavans, and pterocarpans. Structural determination, was accomplished by spectroscopic analysis, particularly 2D NMR and ESI-MS/MS techniques. The present study appears to be the first report on the occurrence of isoflavonoids in Mexican propolis. In addition, the presence of compounds with a 1,3-diarylpropane and 1,3-diarylpropene carbon skeleton were found for the first time in propolis. Isolated compounds 1-10 indicated the possible relation between red Mexican propolis and the genus Dalbergia.

[Carbohydrate study for 40 years]

This review describes the carbohydrate study and the natural product related to the glycoside chemistry. What shall the people in the field of pharmacognosy and natural products chemistry search in scene in future? Forty years before while isolating dimeric compound having naphthoquinonepyrone skeleton from the coloring material produced by the pathogen that hosted in wheat and caused rotten root disease, silica gel has to be treated with oxalic acid to reduce the absorbency before separation. However now a days, availability of reversed phase adsorbents for liquid chromatography has made the separation and isolation of complex compounds possible, easy and rapid. With the advancement of mechanical/physicochemical analytic methods, it has even been possible to isolate traces of compounds present in complex. This advancement has made it possible to determine structure of saponins and complex polysaccharides without decomposition and carry out in vitro bioassay at the same time using various cells on-line. Further, this review describes the oligosaccharide syntheses and biological activities of glycosphingolipids, focusing especially on those found in invertebrates.

Enantioselective iridium-catalyzed allylic arylation

We describe herein the development of the first iridium-catalyzed allylic substitution using arylzinc nucleophiles. High enantioselectivities were obtained from the reactions, which used commercially available Grignard reagents as the starting materials. This methodology was also shown to be compatible with halogen/metal exchange reactions. Its synthetic potential is demonstrated by its application towards the formal synthesis of (+)-sertraline.

Antimicrobial property of a herbal preparation containing Dalbergia sissoo and Datura tramonium with cow urine against pathogenic bacteria

In this study, a herbal preparation containing Dalbergia sissoo and Datura stramoium with cow urine (DSDS), was evaluated for its antibacterial potential against pathogenic strains of gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) and gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) bacteria. Antibacterial activity was compared to standard antibiotic drugs i.e. Chloramphenicol (30 mcg), Ampicillin (10 mcg), Nalidixic acid (10 mcg) and Rifampicin (30 mcg). Cow urine extract was found to be most active against both gram-positive as well as gram-negative bacteria. Clinical isolate of S. aureus showed higher sensitivity towards cow urine extract of DSDS than standard strains, and inhibited growth on most regulatory levels such as inhibition of protein, DNA, RNA and peptidoglycan synthesis. The results of the present study shows that the cow urine extract of DSDS may be used as a potent antiseptic preparation for prevention and treatment of chronic bacterial infections.