nan Gopichand

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.

Vascular plants, Kinnaur, Himachal Pradesh, India

In the present study, we provide a checklist of the vascular plants of Kinnaur district situated in the Himachal Pradesh state of India in the western Himalaya. This checklist includes 893 taxa ( viz ., species, subspecies and varieties) belonging to 881 species of angiosperms and gymnosperms distributed among 102 families and 433 genera, and 30 species of pteridophytes. Information about the growth habit, threat and endemicity status is also provided. Our results show that family Compositae is by far the most species rich family with 122 species, followed by Poaceae (69), Rosaceae (58), Leguminosae (49) and Lamiaceae (38). Among the genera, Artemisia is the most diverse genus with 19 species, followed by Potentilla (14), Saussurea (13), Polygonum (11), Astragalus (10), Lonicera (10) and Nepeta (10). Similar to other regions in the western Himalayan range, family-to-genera ratio was 1:4.25 and the genera-to-species ratio was 1:2.04. Out of 893 taxa, our checklist includes 606 herb species, 63 trees, 108 shrubs, 28 climbers, 67 graminoids and 21 sedges and rushes. Of all the species recorded, 108 (12.2%) are endemic to western Himalaya and 27 (3%) are placed under IUCN threatened categories. The present checklist on the flora of Kinnaur provides an important baseline data for further quantitative studies on the characteristics of plant communities in this region and will help in the identification of priority conservation areas.

Simultaneous Quantification of Flavonoids and Biflavonoids in Ginkgo biloba Using RP-HPTLC Densitometry Method

A reversed-phase high-performance thin-layer chromatography (RP-HPTLC) method was developed for the determination of flavonoids (quercetin and kaempferol) and biflavonoids (sciadopitysin, ginkgetin, and bilobetin) in the aqueous methanolic extract of Ginkgo biloba. There have been a number of reports on the quantification of flavonoids in G. biloba using different analytical techniques, but the reported methods are not suitable for routine analysis and also for the simultaneous quantification of flavonoids and biflavonoids in G. biloba. The method employed here used precoated plates of silica gel 60F254 as the stationary phase with dual-run acetonitrile-water-methanol-formic acid (20:20:1:0.005, v/v/v/v) and acetonitrile-water-methanol-formic acid (20:17:1:0.005, v/v/v/v) as mobile phases with densitometric determination of flavonoids and biflavonoids at 254 nm in reflection/absorption mode. The linear regression analysis data for the calibration plots showed a linear relationship (r2 from 0.9706 to 0.9990). The method was validated for accuracy, precision, and robustness. The limits of detection (LOD) and quantification (LOQ) were in the range of 0.12–0.37 µg and 0.60–1.85 µg, respectively, for the analytes. The method is reproducible and convenient for quantitative analysis of these compounds in the leaves of G. biloba. This is the first report of simultaneous densitometry quantification of major flavonoids and biflavonoids in G. biloba using the newly developed and validated RP-HPTLC method.

Temporal and spatial variation in quality of essential oil of Hedychium spicatum and evaluation of its antioxidant activity

The essential oil of Hedychium spicatum rhizome is used in perfumery and medicines. The rhizome is reported to be stomachic, carminative, a bronchodilator stimulant and a tonic. For studying seasonal variation of the composition of its volatiles, rhizomes of H. spicatum were collected from the Council of Scientific and Industrial Research–Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, Himachal Pradesh, India. To study the spatial diversity in essential oil content and composition, the rhizomes were collected from five different locations of Himachal Pradesh. Essential oils obtained by hydro-distillation were evaluated for their chemical composition by gas chromatography (GC) and GC/mass spectrometry (GC/MS) analyses. Twenty-two compounds were identified from the rhizome oil with major components 1,8-cineole, β-eudesmol, β-pinene and 10-epi–γ-eudesmol. All the essential oil samples were evaluated for their antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity. The essential oil extracted from the rhizomes collected from Biling had highest antioxidant activity; hence, it was also tested for cytotoxic activity against C-6, A549 and SiHa cell lines.

Rapid validated RP-HPTLC method for the quantification of major bioactive constituents of Crataegus oxyacantha L.

A reverse phase high-performance thin-layer chromatography (RPHPTLC) method was developed for determination of vitexin, hyperoside, vitexin-2″-O-rhamnoside, quercetin, and apigenin in the Crataegus oxyacantha extract. The method employed precoated plate of RP-18 silica gel 60F254 as the stationary phase with acetonitrile-methanol-water-formic acid (10:10:20:0.05, v/v) as mobile phase, and densitometric determination was carried out at wavelength 254 nm in reflection/absorption mode. The linear regression analysis data for the calibration plots showed linear relationship (r) from 0.9985 to 0.9992. The method was validated for accuracy, precision, and robustness. The limits of detection and quantification were in the range of 100–300 ng and 310–960 ng, respectively, for analytes. The method is reproducible and convenient for quantitative analysis of these flavonoids in the leaves of C. oxyacantha. This is the first report of simultaneous densitometry quantification of major bioactive constituents in C. oxyacantha by developed and validated RP-HPTLC method. The change in the content of bioactive constituents with growth of the plant was also examined in leaf samples collected for 2 years.