Kaurene as the major constituent of the essential oils of the narcotic plant, Khat (<i>Catha edulis</i> Forsk)

<p>Khat (<i>Catha edulis</i> Forsk) is a narcotic plant which contains significant amounts of amphetamines, like alkaloids. Herein, analysis of the essential oil composition showed that Khat has useful volatile chemicals in addition to its alkaloids. Results indicated that among 35 identified constituents including mono and sesquiterpenes, the diterpene kaurene, comprises the major part of the essential oil, around 50 percent of total. Kaurene is known as a potent biological agent for the treatment of cancer patients. The presence of kaurene at high levels indicates that the essential oil of <i>Catha edulis</i> can potentially be more effectively exploited rather than its narcotic stimulant amphetamine-like alkaloids.</p

The Role of Salicylic Acid and Chitosan Foliar Applications ‎under Drought Stress Condition on Some Physiological Traits ‎and Oil Yield of Safflower (Carthamus tinctorius L.)‎

To study the effects of drought and foliar applications of salicylic acid and chitosan on some physiological traits and oil yield of safflower under drought a split plot experiment with three replications based on a randomized complete block design was conducted at the University of Zabol, Iran. Treatments were three levels irrigations at 25, 50 and 75% of soil available water assigned to main plots, and four levels of foliar applications of salicylic acid and chitosan (control, 0.424 g/liter of salicylic acid, 5 g/liter of chitosan and mixed application of salicylic acid and chitosan) to sub-plots. Water stress reduced oil yield and phosphorus, potassium and calcium contents of shoot. Oil yield was decreased with increasing drought stress by 11% as compared to that of control. Severe water stress also increased the amount of sodium in seed, but its effects on nitrogen and iron control of shoot, membrane stability index and relative humidity were not significant. Foliar application of salicylic acid and chitosan increased macronutrients (nitrogen, phosphorus and potassium) and micronutrients (calcium and iron). Seed oil yield was not affected by foliar spray. In general, combined application chitosan and salicylic acid on traits under study was effective. It can be suggested that combined application of chitosan and salicylic acid could be effective in growing safflower at this region

Essences in Metabolic Engineering of Lignan Biosynthesis

Lignans are structurally and functionally diverse phytochemicals biosynthesized in diverse plant species and have received wide attentions as leading compounds of novel drugs for tumor treatment and healthy diets to reduce of the risks of lifestyle-related non-communicable diseases. However, the lineage-specific distribution and the low-amount of production in natural plants, some of which are endangered species, hinder the efficient and stable production of beneficial lignans. Accordingly, the development of new procedures for lignan production is of keen interest. Recent marked advances in the molecular and functional characterization of lignan biosynthetic enzymes and endogenous and exogenous factors for lignan biosynthesis have suggested new methods for the metabolic engineering of lignan biosynthesis cascades leading to the efficient, sustainable, and stable lignan production in plants, including plant cell/organ cultures. Optimization of light conditions, utilization of a wide range of elicitor treatments, and construction of transiently gene-transfected or transgenic lignan-biosynthesizing plants are mainly being attempted. This review will present the basic and latest knowledge regarding metabolic engineering of lignans based on their biosynthetic pathways and biological activities, and the perspectives in lignan production via metabolic engineering

Phenolic content and antioxidant properties of seeds from different grape cultivars grown in Iran

<p>This study investigated the antioxidant activity and phenolic composition of seed extracts from three grape cultivars grown in Iran. Folin Ciocalteu method was used for the determination of the total phenolic contents and GC–MS was used for the analysis of phenolic compositions. 1,1-diphenyl-2-picrylhydrazyl (DPPH) method was used to evaluate the antioxidant activity. The highest and the lowest total phenolic contents of seed extract were found in the black and green grape, respectively. The content of individual phenols such as Frulic acid, Gentistic acid, Syringic acid, (+) Catechin, Chlorogenic acid and (−)- Epicatchin gallate was cultivars dependent. The antioxidant activity of the seed extracts ranged from 34.03% (Green) to 53.63% (Black). Generally, the Black grape seed extract with the total phenolic content (3 ± 0.01 mg tannic acid/g DM), DPPH (53.63 ± 0.34%), IC₅₀ and AEAC (7.41 and 16.92 mg/mL) showed the highest level of total antioxidant capacity.</p