12-methoxycarnosic Acid Research Articles

Alpha-Glucosidase and Alpha-Amylase Inhibitory Activities, Molecular Docking, and Antioxidant Capacities of Salvia aurita Constituents.

Diabetes mellitus (DM) is one of the most dangerous metabolic diseases with a high rate of mortality worldwide. It is well known that insulin resistance and deficiency in insulin production from pancreatic β-cells are the main characteristics of DM. Due to the detrimental side effects of the current treatment, there is a considerable need to develop new effective antidiabetic drugs, especially alpha-glucosidase and alpha-amylase inhibitors with lesser adverse effects. These inhibitors are known to be directly involved in the delay of carbohydrate digestion, resulting in a reduction of glucose absorption rate and, consequently, reducing the postprandial rise of plasma glucose, which can reduce the risk of long-term diabetes complications. Furthermore, natural products are well-known sources for the discovery of new bioactive compounds that can serve as scaffolds for drug discovery, including that of new antidiabetic drugs. The phytochemical investigation of Salvia aurita collected from Hogobach Pass, Eastern Cape Province, South Africa (SA), yielded four known abietane diterpenes namely carnosol (1), rosmanol (2), 7-methoxyrosmanol (3), 12-methoxycarnosic acid (4), and one flavonoid named 4,7-dimethylapigenin (5). Structural characterization of these isolated compounds was conducted using 1 and 2D NMR, in comparison with reported spectroscopic data. These compounds are reported for the first time from S. aurita. The biological evaluation of the isolated compound against alpha-glucosidase exhibited strong inhibitory activities for 3 and 2 with the half maximal inhibitory concentration (IC50) values of 4.2 ± 0.7 and 16.4 ± 1.1 µg/mL respectively, while 4 and 1 demonstrated strong alpha-amylase inhibitory activity amongst the isolated compounds with IC50 values of 16.2 ± 0.3 and 19.8 ± 1.4 µg/mL. Molecular docking analysis confirms the strong inhibitory activity of 3 against alpha-glucosidase. Additionally, excellent antioxidant capacities were displayed by 2, 1, and 3, respectively, with oxygen radical absorbance capacity (ORAC) (25.79 ± 0.01; 23.96 ± 0.01; 23.94 ± 0.02) mM Trolox equivalent (TE)/g; 1 and 2 as ferric-ion reducing antioxidant power (FRAP) (3.92 ± 0.002; 1.52 ± 0.002) mM ascorbic acid equivalent (AAE)/g; 5 and 2 as Trolox equivalent absorbance capacity (TEAC) (3.19 ± 0.003; 2.06 ± 0.003) mM TE/g. The methanolic extract of S. aurita is a rich source of abietane diterpenes with excellent antioxidant and antidiabetic activities that can be useful to modulate oxidative stress and might possibly be excellent candidates for the management of diabetes. This is the first scientific report on the phytochemical isolation and biological evaluation of the alpha-glucosidase and alpha-amylase inhibitory activities of Salvia aurita.

Application of UHPLC-ESI-QTOF-MS in Phytochemical Profiling of Sage (Salvia officinalis) and Rosemary (Rosmarinus officinalis)

AbstractUHPLC with QTOF-MS is widely used as a powerful tool for metabolomic analysis. This technology has recently been applied to the analysis of polyphenols in food and herb extracts. Sage (Salvia officinalis) and rosemary (Rosmarinus officinalis), belonging to the family Lamiaceae, are known for their potent antioxidant properties due to the presence of polyphenols. We have developed a sensitive and reproducible UHPLC-QTOF-MS/MS-based method for comprehensive phytochemical profiling and the identification and quantitation of specific polyphenolic compounds present in sage and rosemary leaves. The herbs were extracted ultrasonically using methanol as the solvent. In sage, rosmarinic acid (17 678.7±673.4 µg/g) and 12-methoxy carnosic acid (21 918.3±715.4 µg/g) were found in the highest concentrations among all polyphenols. In contrast, rosmarinic acid (14 311.0±636.4 µg/g), luteolin-3'-acetyl-O-glucuronide (1488.50±47.58 µg/g), and luteolin-7-O-glucuronide (1053.68±68.83 µg/g) were observed in the highest concentrations in rosemary. Sagerinic acid, rosmanol, rosmadial, carnosol, and carnosic acid were found in abundance in both sage and rosemary. The pentacyclic triterpenoid, corosolic acid ([M - H]¯ m/z 471.35), was detected for the first time in both plants. Of the 47 polyphenolic compounds identified in each plant, 38 compounds were found in common in rosemary and sage. A flavonoid compound, baicalin ([M -H]¯ m/z 445.08), was identified for the first time in S. officinalis. Also, pectolinarigenin ([M - H]¯ m/z 313.07), a dimethoxyflavone, was detected for the first time in both sage and rosemary leaves.

UHPLC-ESI-QTOF-Mass Spectrometric Assessment of the Polyphenolic Content of Salvia officinalis to Evaluate the Efficiency of Traditional Herbal Extraction Procedures

The healing properties of Salvia officinalis L., Lamiaceae, sage are well known. The presence of high levels of polyphenols in S. officinalis leaves is responsible for many of the therapeutic benefits of the herb. This study used ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry in conjunction with extensive mass spectral libraries to identify the polyphenols with high sensitivity. The study aimed to evaluate the effectiveness of six different traditional extraction procedures (fresh tissue homogenization, fresh and dry leaf decoction, and their respective fermentation) for efficient recovery of phytochemicals using data-independent acquisition in negative electrospray ionization mode. The concentrations of caffeic acid (477.57 ± 7.26 μg/g) and rosmarinic acid (13,694.13 ± 112.06 μg/g) in fermented dry leaf decoctions were found to be significantly higher than in other extracts. However, the dry leaf decoction yielded significantly higher levels of the flavonoid luteolin-7-O-glucoside (691.60 ± 9.81 μg/g) and the terpenoids carnosol, carnosic acid, and ursolic acid (215.61 ± 4.92 μg/g, 529.61 ± 9.61 μg/g, and 19.90 ± 0.22 μg/g, respectively). Two flavonoid compounds, diosmetin ([M-H]− m/z 299.0554) and pectolinarigenin ([M-H]− m/z 313.0715), were identified for the first time in S. officinalis. Among fifty-four identified polyphenols, gallocatechin, scutellarin, sagerinic acid, salvianolic acids, pectolinarigenin, rosmanol, rosmadial, and 12-methoxy carnosic acid were found in higher intensities. Dry leaf decoction and its fermentation were found to be the most efficient traditional extraction methods for polyphenols in S. officinalis.

Edible coating composed of chitosan and Salvia fruticosa Mill. extract for the control of grey mould of table grapes.

Consumer concerns regarding high-quality produce, free of pesticide residues, direct research towards disease management strategies that minimise or even exclude the use of synthetic chemistries in crop production. The efficacy of a chitosan-based edible coating combined with the acetonic extract of Salvia fruticosa Mill. (ASF) was assessed against the grey mould of table grapes. HPLC-SPE-NMR and q-NMR analyses defined major constituents of ASF to be the flavonoids hispidulin, salvigenin and cirsimaritin and the diterpenes carnosic acid, carnosol and the 12-methoxycarnosic acid. The extract was found to be efficacious in reducing spore germination and mycelial growth of Botrytis cinerea in vitro at 10 and 25 °C. However, the combination of the ASF with chitosan 1% (w/v; CHIT) significantly improved fungal inhibition. Similarly, in fruit inoculation trials at 10 °C, the efficacy of the combined application of the ASF at 500 mg L-1 with CHIT against grey mould was statistically equal to the synthetic fungicide thiabendazole, ranging from 98.4% to 92.7% at 12 and 21 days post-inoculation, respectively. Furthermore, chitosan coating alone and in combination with ASF decreased the rate of fruit weight loss during cold storage, while preserved soluble solids content and titratable acidity. Chitosan-based coatings did not affect quality attributes and the bioactive compounds in table grapes. The combined application of the ASF in the form of an edible coating with chitosan could effectively control B. cinerea without deteriorating quality and physico-chemical properties of grapes. © 2016 Society of Chemical Industry.

A bioguided identification of the active compounds that contribute to the antiproliferative/cytotoxic effects of rosemary extract on colon cancer cells

Rosemary extracts have exhibited potential cytostatic or cytotoxic effects in several cancer cell models but their bioactive compounds are yet to be discovered. In this work, the anticancer activity of a rosemary-leaf extract and its fractions were assayed to identify the phenolic compounds responsible for their antiproliferative/cytotoxic effects on a panel of human colon cancer cell lines. Bioguided fractionation of the rosemary-leaf extract was achieved by semi-preparative chromatography. The rosemary extract and the compounds in the fractions were characterized and quantified by HPLC-ESI-QTOF-MS. Cellular viability in the presence of these fractions and the whole extract was determined after 24 or 48 h incubations by using an MTT assay. Fractions containing diterpenes or triterpenes were the most active but not as much as the whole extract. In conclusion, carnosic acid, carnosol, 12-methoxycarnosic acid, taxodione, hinokione and betulinic acid were the putative candidates that contributed to the observed antiproliferative activity of rosemary in human colon cancer cells. Whether the effects of the extract and fractions are only cytostatic or cytotoxic needs to be elucidated. Nevertheless, the comparative antiproliferative study on the fractions and whole extract revealed potential synergistic effects between several components in the extract that may deserve further attention.

HPLC-SPE-NMR characterization of major metabolites in Salvia fruticosa Mill. extract with antifungal potential: relevance of carnosic acid, carnosol, and hispidulin.

Plant pathogenic fungi are considered of significant economic importance for adversely affecting both quantitatively and qualitatively fresh and processed produce. Extracts of Salvia fruticosa were initially screened for their antifungal activity, and the ethyl acetate fraction, being the most active, was further analyzed using HPLC-SPE-NMR hyphenation. The methoxylated flavones hispidulin, salvigenin, and cirsimaritin and the diterpenes carnosic acid, carnosol, and 12-methoxycarnosic acid were identified as the major components of the extract. In addition, the concentration levels of all identified components were determined using q-NMR. The antifungal activity of the crude extract and selected phytochemicals was estimated against the fungal species Aspergillus tubingensis, Botrytis cinerea, and Penicillium digitatum. The estimated MIC and MFC values of the ethyl acetate extract of S. fruticosa, as well as three of its major constituents, carnosic acid, carnosol, and hispidulin, support their antifungal activity, especially against B. cinerea and P. digitatum, suggesting their potential use in food and agricultural systems.

Antileishmanial activity of 12-methoxycarnosic acid from Salvia repens Burch. ex Benth. (Lamiaceae)

In South Africa, Salvia repens is used traditionally to treat sores, stomach ache and diarrhoea. The high performance liquid chromatography (HPLC)-based activity profiling of S. repens whole plant extract showed an active abietane diterpene, identified as 12-methoxycarnosic acid (1) which showed antiprotozoal activity against axenically grown Leishmania donovani amastigotes with an IC50 of 0.75μM with marginal cytotoxicity against the L6-cells (IC50, 17.3μM).

Promotion of Hair Growth by Rosmarinus officinalis Leaf Extract

Topical administration of Rosmarinus officinalis leaf extract (RO-ext, 2 mg/day/mouse) improved hair regrowth in C57BL/6NCrSlc mice that experienced hair regrowth interruption induced by testosterone treatment. In addition, RO-ext promoted hair growth in C3H/He mice that had their dorsal areas shaved. To investigate the antiandrogenic activity mechanism of RO-ext, we focused on inhibition of testosterone 5α-reductase, which is well recognized as one of the most effective strategies for the treatment of androgenic alopecia. RO-ext showed inhibitory activity of 82.4% and 94.6% at 200 and 500 µg/mL, respectively. As an active constituent of 5α-reductase inhibition, 12-methoxycarnosic acid was identified with activity-guided fractionation. In addition, the extract of R. officinalis and 12-methoxycarnosic acid inhibited androgen-dependent proliferation of LNCaP cells as 64.5% and 66.7% at 5 µg/mL and 5 μM, respectively. These results suggest that they inhibit the binding of dihydrotestosterone to androgen receptors. Consequently, RO-ext is a promising crude drug for hair growth.

Supercritical Fluid Extracts of Rosemary Leaves Exhibit Potent Anti-Inflammation and Anti-Tumor Effects

Supercritical fluid SF-CO2 treatment of Rosemarinus officinalis L. fresh leaves under optimum conditions (80 degrees C at 5,000 psi) yielded 5.3% of extract supercritical fluid extraction (SFE)-80, in which five major active principles were identified by liquid chromatography/mass spectrometry (LC/MS), viz., rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. Total phenolic content was 155.8 mg/ gallic acid equivalent (GAE)/g in SFE-80, which showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging of 81.86% at 0.01 mg/ml. When treated in RAW 264.7, apparent dose-dependent NO inhibition occurred at dosages of 1.56 to 6.25 microg/ml, and more drastically at 12.5 and 25 microg/ml. At 0.5 to 5.0 microg/ml, SFE-80 exhibited dose-dependent viability suppression and significant tumor necrosis factor alpha (TNF-alpha) production in Hep 3B, whereas no effect was found in Chang liver cells. Furthermore, no effect was observed in RAW 264.7 at dosages of 3.13 to 25 microg/ml, indicating that SFE-80 exhibited a noncytotoxic character. Conclusively, rosemary can be considered an herbal anti-inflammatory and anti-tumor agent.

Low-Density Lipoprotein, Collagen, and Thrombin Models Reveal that Rosemarinus officinalis L. Exhibits Potent Antiglycative Effects

Using the low-density lipoprotein (LDL), collagen, and thrombin models, we report here that the rosemary extracts (REs), either the aqueous (REw) or the acetonic (REA), all possessed many antiglycation-related features, and the effective concentrations required were as follows: 0.1 mg/mL for suppressing the relative electrophoretic mobility, 1.3 microg/mL for anticonjugated diene induction, 0.5 mg/mL for inhibition of thiobarbituric acid reactive substances production, 0.1 mg/mL for AGEs (advanced glycation end products) formation, 0.1 mg/mL to block glucose incorporation, and 0.05 mg/mL as an effective anti-antithrombin III. Using high-performance liquid chromatography/mass spectrometry, we identified five major constituents among eight major peaks, including rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. In the LDL model, REA was proven to be more efficient than REw; yet, the reverse is true for the collagen and the thrombin III models, the reason of which was ascribed to the higher lipid-soluble antioxidant content (such as rosmarinic acid, carnosol, carnosic acid, 12-methoxycarnosic acid and methyl carnosate) in REA than in REw and the different surface lipid characteristics between LDL and collagen; although to act as anti-AGEs, both extracts were comparable. To assist the evidence, a larger 2,2-diphenyl-1-picrylhydrazyl radical scavenging capability with less total polyphenolic content was found in REA. We conclude that rosemary is an excellent multifunctional therapeutic herb; by looking at its potential potent antiglycative bioactivity, it may become a good adjuvant medicine for the prevention and treatment of diabetic, cardiovascular, and other neurodegenerative diseases.

Development of a triple hyphenated HPLC–radical scavenging detection–DAD–SPE–NMR system for the rapid identification of antioxidants in complex plant extracts

A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC–DAD–SPE–NMR system. Using this method a commercial rosemary extract was investigated. All major compounds present in the extract were collected on SPE cartridges after their separation. Advantages of on-line SPE peak trapping are the possibility to perform HPLC with non-deuterated solvents, a concentration effect and being able to record NMR spectra in pure 100% deuterated solvents. After comparing DAD and DPPH scavenging chromatograms, 1H NMR spectra of compounds having radical scavenging activities were recorded. Afterwards all compounds were collected and infused into an ESI-MS. The five main active compounds – carnosol, carnosic acid carnosaldehyde, 12-methoxycarnosic acid and epiisorosmanol – could be identified from the combined UV, NMR and mass spectral data without actually isolating them. It was possible to record on-line an HMBC spectrum of carnosic acid. Also one compound was tentatively identified as epirosmanol methyl ether.

Terpenoids from Salvia lanigera

Two new terpenoids, 12-methoxycarnosic acid and 3β-hydroxyoleanan-13β → 28 lactone, have been isolated from the leaves of Salvia lanigera, together with two known diterpenes and two triterpenes.