Carl E. Vandercook

Phenolic composition of various tissues of rutaceae species

Abstract A survey of phenolic compounds using HPLC was performed in Rutaceae, subfamily Aurantioideae, representing five genera, 35 species and 114 cultivars. T

Development of an automated plant culture system

An apparatus was constructed that could be used to grow plant tissues, organs, and whole plantlets under sterile conditions. This system accommodated independent or multiple concurrent growth of cultures. Growth of plants either equalled or exceeded that observed using the manual transfer procedure. The automated plant culture system (APCS) consists of silicone tubing, 2 impeller pumps, 2 glass medium reservoir bottles, a 3-way stainless steel valve, a plant culture chamber, and an interface module containing relay boards. Control of the APCS is through interfacing with a microcomputer (e.g. Apple IIe or Atari 400). The computer controlled medium introduction, evacuation, and replenishment in a sterile environment. The APCS was inexpensively constructed and provides a labor-saving, long-term method to culture plants in vitro.

Biosynthesis of naringin and prunin in detached grapefruit

Abstract [ 14 C]Acetate and [ 14 C]phenylalanine were fed to detached immature grapefruit ( Citrus paradisi Macfad.) fruits and two radiolabelled flavanone glycosides were detected. TLC analysis and enzymatic hydrolysis studies indicated that the two labelled flavonoids were naringin (naringenin 7- O -β-neohesperidoside) and prunin (naringenin 7- O -β-glucoside). Prunin, which has not been previously shown to be present in grapefruit, was then detected in immature peel. This indicates that immature grapefruits are capable of biosynthesizing flavonoids from simple precursors and suggests that multiple-glycosylation of flavanones may occur by the addition of discrete single sugar units.

Flavonoid changes in developing lemons grown in vivo and in vitro

Abstract Concentrations and HPLC profiles of the major flavonoids of lemon juice vesicles ( Citrus limon cv. Eureka) were determined for tree-grown fruit 2–55 mm diameter and in 25–30 mm diameter fruit halves cultured in vitro for up to four months. In tree-grown fruit, the total amount of hesperidin per lemon accumulates rapidly from fruit set to its maximum value at the 25–30 mm diameter stage; and thereafter the concentration continually decreases as the fruit increases in diameter. At the 25–30 mm stage, the total amount of eriocitrin begins to increase rapidly and continues until the fruit reaches full size. The amount of diosmin per fruit increases gradually throughout the development of the lemon. Flavonoids of juice vesicles from in vitro cultured fruit halves show a pattern of development similar to fruit grown on the tree. In contrast, flavonoid patterns from callus derived from juice vesicles were quite dissimilar to those of developing fruit.

Sites of Naringin Biosynthesis in Grapefruit Seedlings

Summary Radioactively-labeled acetate and phenylalanine were fed to intact and detached tissues of grapefruit seedlings to characterize the biosynthesis and subsequent metabolic fate of the flavanone glycoside naringin. Radiolabeled naringin was biosynthesized from both precursors in detached leaves, but not in detached stems or roots. Young leaves were much more efficient at incorporating label into naringin than older leaves. When radiolabeled precursors were fed to whole seedlings, labeled naringin was found in all parts of the plant, including stems and roots. This suggests that naringin is synthesized in young, rapidly growing leaves, then transported to other parts of the plant.

Detection of adulteration in citrus juice beverages

Abstract The detection of adulteration in citrus juices is a challenge to industry and regulatory agencies. Early work was directed towards detecting citric acid added to lemon juice. More recently, efforts have been made to develop methods of detecting adulteration in orange juice and to determine orange juice content in diluted orange beverages.

A malonic acid ester derivative of naringin in grapefruit

Abstract A malonic acid ester derivative of the flavanone naringin was abundant in the young leaves and fruits of grapefruit plants, but not in the mature leaves and fruits. After isolation, the structure of this compound was established as naringin 6″-malonate (naringenin 72″- O -α- l -rhamnosyl)-β- d -glucoside 6″-malonate).

Automation of the surface sterilization system procedure.

Reliable methods for obtaining sterile explants (i. e., that part of the parent plant introduced to in vitro conditions) are critical in tissue culture. Normally, explants are soaked in disinfectants in order to eliminate the coating layer of microorganisms ubiquitously found on plants. This chapter is concerned with the use of mechanical and electronic techniques (i. e., an automated Surface Sterilization System [SSS]) to aid in the sterile establishment of explants. The automated SSS reduces labor input and increases the effectiveness and reproducibility of the surface sterilization treatment (1) (see Fig. 1). Numerous disinfectant types and techniques have been developed to surface sterilize plants (2). However, all procedures can be summarized as follows.