Isolation and structure elucidation of highly antioxidative 3,8″-linked biflavanones and flavanone-C-glycosides from Garcinia buchananii bark

The aim of this study was to identify antioxidants from Garcinia buchananii bark extract using hydrogen peroxide scavenging and oxygen radical absorbance capacity (ORAC) assays. LC-MS/MS analysis, 1D- and 2D-NMR, and circular dichroism (CD) spectroscopy led to the unequivocal identification of the major antioxidative molecules as a series of three 3,8″-linked biflavanones and two flavanone-C-glycosides. Besides the previously reported (2R,3R,2″R,3″R)-naringenin-C-3/C-8″ dihydroquercetin linked biflavanone (GB-2; 4) and (2R,3S,2″R,3″R)-manniflavanone (3), whose stereochemistry has been revised, the antioxidants identified for the first time in Garcinia buchananii were (2R,3R)-taxifolin-6-C-β-D-glucopyranoside (1), (2R,3R)-aromadendrin-6-C-β-D-glucopyranoside (2), and the new compound (2R,3S,2″S)-buchananiflavanone (5). The H?O? scavenging and the ORAC assays demonstrated that these natural products have an extraordinarily high antioxidative power, especially (2R,3S,2″R,3″R)-manniflavanone (3) and GB-2 (4), with EC?? values of 2.8 and 2.2 μM, respectively, and 13.73 and 12.10 μmol TE/ μmol. These findings demonstrate that G. buchananii bark extract is a rich natural source of antioxidants.     

Effects of supplemental‐nitrogen on the quality of rice proteins

A study was conducted on the effect of supplemental nitrogen (N) (20 hg/ha) applied as a foliar spray or to the soil on seed production, protein percentage, and protein fractions of rice. Plants were grown in a greenhouse over two different periods of time, i.e., August 1988 to January 1989 (Period I), and December 1988 to April 1989 (Period II). Nitrogen was applied to the leaves 10 and 20 days after anthesis (DAA), and to the soil at anthesis and at 15 DAA. Average temperature was 28.7°C during Period I and 32°C during Period II, corresponding to 18.7 and 22.0 growing degree‐day/day (GDD/day), respectively. The difference in GDD/day reduced the plant cycle from 130 days during Period I to 109 days during Period II. Plants grown during Period II had larger numbers of spikelets, a higher percentage of “full grown grains”;, and higher grain weight. Although percentage crude protein was about the same for the two periods, prolamin content was increased and the albumin+globulin fraction was decreased during Period II, but with no difference in glutelin content. The increase in number of spikelets, percent full grains, and grain weight appeared to result in a greater energy demand for plants grown during Period II. This may explain the increase in prolamins, since prolamin synthesis requires less energy than globulin or albumin synthesis. There was a simultaneous decrease in albumin and globulin synthesis during Period II. The content of glutelins, which represent the major reserve proteins in rice grains, was constant during both periods.     

Influence of irrigation and nitrogen management on potato yield and quality

The effects of irrigation, water and nitrogen management on yield and quality of the Russet Burbank cultivar are discussed relevant to developmental stages of growth. Recent research on the interactions of irrigation and nitrogen management on total and U.S. No. 1 yields and specific gravity are presented. Total and U.S. No. 1 yields decline with increasing soil moisture stress. Yield of U.S. No. 1 potatoes is particularly sensitive to short periods of irrigation deficit during tuber initiation. Total yield appears most sensitive to short periods of irrigation deficit during tuber bulking. Allocation of longer term irrigation deficits during years of limited water supply should be either a) avoided during mid-season tuber bulking, or b) uniformly distributed over the entire tuber bulking growth period. Yield increases with higher total available soil nitrogen under deficit irrigation, but the yield response diminishes as the amount of total seasonal water decreases. The influence of irrigation and nitrogen availability is also discussed for specific gravity and tuber maturity. Seasonal (split) nitrogen management is proposed as a method to improve yield, quality and nitrogen fertilizer use efficiency of indeterminant cultivars.     

Relationship between foliage temperature and water stress in potatoes

Field studies were conducted in southern Idaho to evaluate the possibility of using thermal infrared measurements of potato foliage to detect soil water deficits. Concurrent measurements of foliage-air temperature differences (T_f-T_a), leaf water potential (gy_leaf) and vapor pressure deficit (VPD) were obtained from differentially-irrigated Russet Burbank and Kennebec potatoes during the 1982 and 1983 growing seasons. Foliageair temperature differences for well-watered potatoes were linearly related to VPD. Differences in T_f-T_a values between stressed and well-watered potatoes were relatively small in the early morning when evaporative demand was low. However, severe soil water deficits caused afternoon T_f-T_a values to rise as much as 8.0 C above non-stressed levels under conditions of high VPD. Foliage-air temperature differences and VPD data were used to construct a plant water stress index (PWSI) which reflected the rise in T_f-T_a above non-stressed levels at a given VPD. The PWSI was linearly related to depressions in gy_leaf caused by moderate to severe soil water deficits. However, the PWSI did not increase significantly above non-stressed values unless the soil matric potential gy_soil fell below -70 kPa (centibars). Since potatoes are normally irrigated before gy_soil falls below ?60 kPa, it appears that foliage temperature measurements cannot be used to effectively schedule irrigation for this crop.     

Biochemical characteristics of potato clones differing in blackspot susceptibility

The relationships between enzymatic discoloration and selected biochemical characteristics of tubers from nine clones were determined in an attempt to explain varietal differences in blackspot susceptibility. These nine clones represent a wide range of blackspot susceptibility as determined by two discoloration indices after abrasive peeling. Enzymatic discoloration for combined data from the 1983 and 1984 growing seasons was highly correlated with total phenol (r=0.89) and tyrosine (r=0.85) concentrations. Conversely, discoloration was negatively correlated with soluble protein in 1983 (r=-0.78) and 1984 (r=-0.77). Polyphenoloxidase (PPO) activities, apparent Michaelis constants and maximum velocity values, from crude and partially purified enzyme preparations, were not significantly correlated with enzymatic discoloration. Varietal susceptibility to enzymatic discoloration appears to be related to concentrations of endogenous phenolic substrates of PPO, rather than to differences in the quantity or properties of the PPO enzyme.     

Osmotic Adjustment and Growth of Salt-stressed Cotton as Improved by a Bioregulator

For examining links between growth of salinity-exposed cotton and corresponding changes in physiological characters, a bioregulator was used as a tool for specific manipulations. Greenhouse-grown cotton ( Gossy-pium birsutum L. cv. Paymaster 145 ) was subjected to NaCl levels up to 14.9 dS m⁻¹. The bioregulator MCBuTTB, a cytokinin analog with known ability in improving growth and yield in several salt-stressed crops, was applied by imbiding seed (0 or 268 ppm) plus one foliar spray in dosages equaling 0, 1, and 3 kg ha⁻¹ at 45 DAP. MCBuTTB improved germination, growth, flowering, and finally boll weight. This result coincided with lower osmotic and higher water potentials in leaves, higher leaf turgidity, and more agilely reacting stomata. Treated plants had higher K and preferably Na concentrations in its leaves but ion accumulation was not a precondition for osmotic adjustments, because in cotton exposed to a manmtol-simulated drought MCBuTTB triggered a similar osmotic adjustment and sustained vigour. Regression analyses indicated that osmotic adjustment alone did not cause the raised leaf turgidity. All characters which contribute to salinity resistance appeared as mutually depending and interacting but they respond to a regulatory agent of cytokinin-like activity.     

Extraction of an infected tusk in an adult African elephant

An 18-year-old African elephant was determined to have a nonrepairable crack in its left tusk. Treatment included extraction of the tusk, using rotational and extractional forces, and administration of antibiotics, followed by 1 year of flushing the opened tusk cavity with warm tap water. Two years after surgery, the elephant was healthy, and the tusk cavity was 80% filled with normal tissue.     

Genetic Fingerprinting of Potato Varieties from the Northwest Potato Variety Development Program

The Northwest Potato Variety Development (NWPVD) Program has released 45 improved potato varieties since 1985. Thirty-four potato varieties, four breeding clones and two advanced selections from NWPVD Program, and six commonly-grown potato varieties were fingerprinted using 32 simple sequence repeat (SSR) markers and 12,808 single nucleotide polymorphism (SNP) markers. Of 32 SSR markers, 29 exhibited significant polymorphism across all the 46 potato clones studied. A total of 143 alleles were observed with an average of 4.6 alleles per SSR marker. These markers span all 12 chromosomes of potato, with a maximum of five markers from chromosome VIII and minimum of one marker from chromosome VI. The polymorphic information content (PIC) and expected heterozygosity (H_e) of the SSR markers ranges between 0.18 to 0.75 and 0.20 to 0.78, respectively. Based on PIC, H_e, and ease of scoring, we recommend a set of eight SSR markers: STG0016, STI0004, STI0012, STI0023, STI0030, STI0033, STM1016 and STM1104 for fingerprinting NWPVD varieties. Out of 12,808 SNPs, 88.8% resulted in reliable three cluster diploid calling of which 87.8% were polymorphic. Tetraploid calling resulted in 44.2% of SNPs of which 94.5% were polymorphic. Our study provided fingerprinting resources for the NWPVD varieties and can be used in issues related to intellectual property rights, ownership, trademark and diversity analysis.     

Anesthesia and pain management in Russia

There was only limited emphasis on anesthesia and pain management in veterinary colleges in Russia until the last ten years. There is now great interest in improvement by Russia practitioners. This effort is hampered by the lack of approved and available medications and limited instructions. At this time, the small animal practitioners have tranquilizers, alpha₂ agonists local anesthetics and NSAID's for their use. Propofol is available through pharmacies and efforts are being made for veterinarians to use ketamine. Only a few practices have inhalant anesthetic units and halothane. During a recent lecture tour of Russia, general clinical principles and specific anesthetic and pain management protocols were taught. The audience, primarily young and progressive veterinarians, actively participated and showed great desire to practice quality anesthesia and pain management for their patients. Teaching young veterinarians how to manage their cases without the availability of opioids, ketamine advanced anesthetic equipment and monitors was indeed challenging. Protocols for perioperative management consisting of medetomidine with or without local anesthesia followed by carprofen for post-operative pain is an improvement. We sometimes spend so much time discussing which of many drug combinations we will use but seldom consider what we would do if we were practicing our specialty in parts of the world where we would have to modify dosages and combinations to achieve humane care with few drug choices.