Phytochemical and antioxidant profiling of Ocimum sanctum.

The leaves of Ocimum sanctum were extracted in methanol (OsM) and sequentially fractionated with n-hexane (OsH), ethylacetate (OsE) and butanol (OsB) to find the best extraction solvent for antioxidants from the herb known for its medicinal values. OsB was rich in both total polyphenolic content (TPC) (212.26 ± 6.3 mg GAE/g extract) and total flavonoid contents (TFC) (54.51 ± 3.5 mg QE/g extract). OsE also had significantly high TPC (202.71 ± 5.5 mg GAE/g extract). The EC50 based on DPPH (3.91 ± 0.3 µg/ml), ABTS (1.6 ± 0.1 µg/ml) and phosphomolybdate (2.31 ± 0.1 µg/ml) for OsB; hydroxyl (5.3 ± 0.4 µg/ml), superoxide (7.32 ± 0.9 µg/ml) radicals for OsM and DPPH (8.61 ± 0.6 µg/ml), phosphomolybdate (2.43 ± 0.1 µg/ml) and ABTS (5.3 ± 0.4 µg/ml) for OsE were lower than ascorbic acid showing potential antioxidant properties. EC50 values of different fractions for DPPH anion, ABTS cation free radical scavenging and phosphomolybdate reducing property were significantly and positively correlated with TPC and TFC. LC-MS analysis of OsB and OsE showed the presence of luteolin, apigenin, rosmarinic, chlorogenic, caffeic acid and their derivatives. Quercetin is extracted in ethylacetate fraction. Overall data revealed that O. sanctum leaf extracts in butanol and ethylacetate with high polyphenolics and flavonoids, had strong antioxidant potential.

Naturally occurring himachalenes to benzocycloheptene amino vinyl bromide derivatives: as antidepressant molecules.

A new series of benzocycloheptene amino vinyl bromide derivatives (9a-9m) were synthesized from isomeric mixture of himachalenes through two-step synthesis. The unusual structure of benzocycloheptene amino vinyl bromide derivative (9a) was confirmed by NMR and X-ray crystallography analyses. The newly synthesized amino vinyl bromide derivatives of benzocycloheptene were further evaluated for their antidepressant activities. The compound 9c had shown significant reduction in the immobility period.

Antifungal sesquiterpenes from Cedrus deodara.

Two new sesquiterpenes, (E)-(2S,3S,6R)-atlantone-2,3-diol (1) and (E)-(2S,3S,6S)-atlantone-2,3,6-triol (2), along with two known sesquiterpenes, atlantolone (3) and (E)-α-atlantone (4), were isolated from Cedrus deodara Loud. The structures of the new compounds were elucidated on the basis of UV, IR, NMR, HR­ESI-QTOF­MS, and EI mass spectral studies. The n-hexane and chloroformextracts of sawdust and compounds 3 and 4 from the plant exhibited antifungal activity against Aspergillus flavus, A. niger, A. ochracoeus, A. parasiticus, and A. sydowii. A weak activity was also recorded against A. parasiticus and A. sydowii for compound 1, while Trichophyton rubrum was inhibited by compound 2 and the extracts.

Spatial and temporal variation of secondary metabolite profiles in Ginkgo biloba leaves.

Terpene trilactones (TTLs) are the main bioactive constituents of Ginkgo biloba used for the preparation of drugs for several ailments. Flavonoid glycosides (FGs) are the significant group of compounds found in Ginkgo leaves used in food and healthcare products. The variation in the content of bioactive constituents, as well as antioxidant activity, with respect to change in altitude and the time of sample collection was investigated. The amount of TTLs varied from 0.218-0.709% w/w, whereas FGs were observed in the range of 0.130-0.209% w/w. Ginkgolides J and A showed significant variation (p ≤ 0.05) with the change in altitude, while other components remained more or less unaffected. The amount of TTLs and FGs were not affected significantly by the time of sample collection. The antioxidant capacity (by using DPPH, ABTS, and FRAP assays) of ginkgo extracts was highly dependent on the altitude, and was at maximum in the samples collected from 1000-2000 m, followed by the samples collected from altitudes lower than 1000 m and higher than 2000 m. Thus, Ginkgo harvested from 1000-2000 m of altitudinal range irrespective of the season could provide better nutraceutical formulations, whereas that from below 1000 m may yield a terpene trilactone-enriched fraction.

Chemical composition and larvicidal activities of the Himalayan cedar, Cedrus deodara essential oil and its fractions against the diamondback moth, Plutella xylostella.

Plants and plant-derived materials play an extremely important role in pest management programs. Essential oil from wood chips of Himalayan Cedar, Cedrus deodara (Roxburgh) Don (Pinales: Pinaceae), was obtained by hydrodistillation and fractionated to pentane and acetonitrile from which himachalenes and atlantones enriched fractions were isolated. A total of forty compounds were identified from these fractions using GC and GC-MS analyses. Essential oils and fractions were evaluated for insecticidal activities against second instars of the diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae), using a leaf dip method. All samples showed promising larvicidal activity against larvae of P. xylostella. The pentane fraction was the most toxic with a LC50 value of 287 µg/ml. The himachalenes enriched fraction was more toxic (LC50 = 362 µg/ml) than the atlantones enriched fraction (LC50 = 365 µg/ml). LC50 of crude oil was 425 µg/ml and acetonitrile fraction was LC50 = 815 µg/ml. The major constituents, himachalenes and atlantones, likely accounted for the insecticidal action. Present bioassay results revealed the potential for essential oil and different constituents of C. deodara as botanical larvicides for their use in pest management.

Nano-bio surface interactions, cellular internalisation in cancer cells and e-data portals of nanomaterials: A review.

Nanomaterials (NMs) have abundant applications in areas such as electronics, energy, environment industries, biosensors, nano devices, theranostic platforms, etc. Nanoparticles can increase the solubility and stability of drug-loaded materials, enhance their internalisation, protect them from initial destruction in the biological system, and lengthen their circulation time. The biological interaction of proteins present in the body fluid with NMs can change the activity and natural surface properties of NMs. The size and charge of NMs, properties of the coated and uncoated NMs, nature of proteins, cellular interactions direct their internalisation pathway in the cellular system. Thus, the present review emphasises the impact of coated, uncoated NMs, size and charge, nature of proteins on nano-bio surface interactions and on internalisation with specific focus on cancer cells. The increased activity of NPs may also result in toxicity on health and environment, thus emphasis should be given to assess the toxicity of NMs in the medical field. The e-data sharing portals of NMs have also been discussed in this review that will be helpful in providing the information about the chemical, physical, biological properties and toxicity of NMs.

Synthesis of novel antimicrobial aryl himachalene derivatives from naturally occurring himachalenes.

Five new 2,9,9-trimethyl-6,7,8,9-tetrahydro-benzocyclohepten-5-ylidene-amine derivatives (16a-16e) were synthesized from α-dehydro-ar-himachalene (11) that was originally prepared from an isomeric mixture of α, ß and γ himachalenes (10), the abundant sesquiterpenes of Cedrus deodara essential oil. In addition, different aryl himachalenes derivatives (9, 12, 14 and 15) were also formed from 11. The structures of the synthesized compounds were confirmed on the basis of their NMR, IR and mass spectral data. The prepared compounds were tested against a group of sixteen organisms including gram positive and gram negative bacterial and fungal strains. The introduction of a series of substituted imine groups into aryl himachalenes at 5(th) position (16a-16e) enhanced antimicrobial activity as compared to the aromatized derivatives (9, 12, 14 and 15) against gram-positive bacteria Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus, and mycotoxigenic fungi Aspergillus parasiticus, A. ochraceous and A. sydowii. graphical Abstract, Figure 1(Fig. 1).

An efficient microwave assisted extraction of phenolic compounds and antioxidant potential of Ginkgo biloba.

Flavonoid glycosides are a significant group of compounds found in Ginkgo biloba leaves, but the long extraction procedures in existing methods are a challenging problem. In this work, a microwave-assisted extraction (MAE) method has been developed for extracting bioactive compounds from G. biloba. Several variables were optimized, such as extracting solvent, microwave power, and extraction time that can potentially affect the extraction yield. The total phenolic content, antioxidant activity (using DPPH, ABTS and FRAP assays) and flavonoid glycosides of different extracts using RP-HPLC were assessed. The antioxidant capacity was found to be highest with MAE using 60% aq. ethanol as extracting solvent and microwave power of 120W for 20 min.

Naturally occurring limonene to cinnamyl-type gamma-butyrolactone substituted aldol condensation derivatives as antioxidant compounds.

A method has been developed for the synthesis of gamma-butyrolactone substituted cinnamyl type Aldol condensation products under milder proline and triethylamine basic conditions. The antioxidant activity of all the synthesized compounds was assessed using three different assays. The cinnamyl type derivatives of gamma-butyrolactone bearing an -OH group in the benzene ring exhibited excellent antioxidant activity.

Chemical fingerprint analysis of phenolics of Albizia chinensis based on ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry and antioxidant activity.

Albizia species have been shown to have anti-inflammatory and anti-allergic properties. However, efficient analytical methods for identification of their active constituents are still lacking. Ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study the phenolic composition of the ethanolic extracts of different parts (flowers, leaves, pods and bark) of A. chinensis. In addition, the antioxidant activity of the ethanolic extracts was evaluated by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical cation scavenging methods. Four compounds were isolated from the ethanolic extract of the flowers and characterized by 1H and 13C NMR spectroscopy as quercetin-3-O-rhamnoside, quercetin, quercetin-3-O-arabinofuranoside, and myricetin-3-O-rhamnoside. Separation and quantification of the phenolics was accomplished using a reversed-phase BEH C18 column with the mobile phase of methanol-water (0.05% formic acid), and detection wavelengths of 360 and 254 nm.

Nanoencapsulation and characterization of Albizia chinensis isolated antioxidant quercitrin on PLA nanoparticles.

The plant isolated antioxidant quercitrin has been encapsulated on poly-d,l-lactide (PLA) nanoparticles by solvent evaporation method to improve the solubility, permeability and stability of this molecule. The size of quercitrin-PLA nanoparticles is 250±68nm whereas that PLA nanoparticles is 195 ± 55nm. The encapsulation efficiency of nanoencapsulated quercitrin evaluated by HPLC and antioxidant assay is 40%. The in vitro release kinetics of quercitrin under physiological condition reveals initial burst release followed by sustained release. Less fluorescence quenching is observed with equimolar concentration of PLA encapsulated quercitrin than free quercitrin. The presence of quercitrin specific peaks on FTIR of five times washed quercitrin loaded PLA nanoparticles provides an extra evidence for the encapsulation of quercitrin into PLA nanoparticles. These properties of quercitrin nanomedicine provide a new potential for the use of such less useful highly active antioxidant molecule towards the development of better therapeutic for intestinal anti-inflammatory effect and nutraceutical compounds.

Optimization of extraction technique and validation of developed RP-HPLC-ELSD method for determination of terpene trilactones in Ginkgo biloba leaves.

Terpene trilactones are potent and selective antagonists of platelet activating factor. The present study deals with standardization of efficient extraction method and validation of newly developed simple, sensitive and rapid reversed phase high performance liquid chromatographic method with evaporative light scattering detection (RP-HPLC-ELSD) method for the quantitative determination of ginkgolide A (GA), ginkgolide B (GB), ginkgolide C (GC), ginkgolide J (GJ) and bilobalide (BB) within 8 min in Ginkgo biloba leaf extract. The analysis was conducted on a Zorbax RP-C18 column with gradient elution of methanol-water-tetrahydrofuran. The method was validated for accuracy, precession, limit of detection and quantification. The drift tube temperature of evaporative light scattering detector was set to 90 degrees C and nitrogen flow rate was 1.5 standard liter/min (SLM).

Chemical composition of hydrodistilled and solvent volatiles extracted from woodchips of Himalayan Cedrus: Cedrus deodara (Roxb.) Loud.

The essential oil and extract obtained from the wood chips of Cedrus deodara by hydrodistillation and percolation respectively have been analyzed by GC-FID and GC-MS techniques. Thirty four compounds were identified from the essential oil and twenty six from the extract accounting for 98.3 and 94.6% respectively of total identifications. While the major components of the oil were beta-himachalene (38.3%), alpha-himachalene (17.1%) and gamma-himachalene (12.6%), those of the extracts were E-gamma-atlantone (38.5%) and E-alpha-atlantone (10.2%).