tannins and alpha-pinene

Pinus species are amongst the most commonly used medicinal plants in Indian Northwestern Himalayas. Nearly all parts of the plant especially needles are believed to possess medicinal and clinical values in traditional systems of medicine such as Ayurvedic, Unani or Homeopathic. They are used to heal numerous diseases, including afflictions of the skin, eyes, throats and ears. Various parts of the plant including needles are rich in biologically active compounds, such as thunbergol, 3-carene, cembrene, α-pinene, quercetin, xanthone, etc. The scientific data available for the biological potential of this plant and its constituents have been found to be scanty and also does not satisfy the basis of their age-old folklore and local uses. This review focuses on a detailed analysis of ethnopharmacognosical studies on the needles of different Pinus species growing naturally in northwestern region of Indian Himalayas including investigations and findings that have come up with a concrete view of the abilities of plant components for example phenolics, flavonoids, tannins and other constituents to treat oxidative, inflammatory and microbial responses. Careful evaluation of the data presented may be helpful for the researchers to discover and evaluate the specific chemical entities responsible for the traditional medicinal uses of P. roxburghii, P.wallichiana, P. merkusii, P.kesiya and P.thunbergii.

Topics: Altitude; Bicyclic Monoterpenes; Ethnobotany; Flavonoids; Humans; India; Phenols; Phytotherapy; Pinus; Plant Extracts; Plant Leaves; Plants, Medicinal; Species Specificity; Tannins

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of alpha-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, beta-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.

Topics: Bicyclic Monoterpenes; Flavonoids; Free Radical Scavengers; Gas Chromatography-Mass Spectrometry; Monoterpenes; Myrtus; Oils, Volatile; Phenols; Plant Components, Aerial; Plant Oils; Polyphenols; Spectrometry, Mass, Electrospray Ionization; Tannins