The Biological Activities of Troponoids and Their Use in Agriculture A Review

Chemical compounds containing the tropone structure (2,4,6-cycloheptatrien-1-one), in their molecule, called troponoids, characterized by a seven-membered ring, are distributed in some plants, bacteria and fungi, although they are relatively rare. ß-Thujaplicin (2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one), also known as hinokitiol, is a natural compound found in several plants of the Cupressaceae family. Besides hinokitiol, related compounds were identified in Cupressaceae trees. It has been demonstrated that hinokitiol and its derivatives have various biological effects, such as antibacterial, antifungal, insecticidal, antimalarial, antitumor, anti-ischemic, iron chelating and the inhibitory activity against polyphenol oxidase activity. Activity similar to ß-thujaplicin has tropolone and its derivatives, which are not present nature. Due to the high scientific and practical interest, synthetic ß-thujaplicin and other troponoids have been produced for many years. In this review, the major biological effects of troponoids, mostly ß-thujaplicin and tropolone, on tyrosinase and polyphenol oxidase activity, ethylene production, antibacterial, antifungal and insecticidal activities, and biotransformation of ß-thujaplicin by cultured plant cells are presented. Accumulation of ß-thujaplicin and related troponoids has been shown in cell cultures of Cupressus lusitanica and other species of Cupressaceae. The biosynthetic pathway of the troponoids in plants, bacteria and fungi has been also briefly described

The Biological Activities of Troponoids and Their Use in Agriculture A Review

Chemical compounds containing the tropone structure (2,4,6-cycloheptatrien-1-one), in their molecule, called troponoids, characterized by a seven-membered ring, are distributed in some plants, bacteria and fungi, although they are relatively rare. ß-Thujaplicin (2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one), also known as hinokitiol, is a natural compound found in several plants of the Cupressaceae family. Besides hinokitiol, related compounds were identified in Cupressaceae trees. It has been demonstrated that hinokitiol and its derivatives have various biological effects, such as antibacterial, antifungal, insecticidal, antimalarial, antitumor, anti-ischemic, iron chelating and the inhibitory activity against polyphenol oxidase activity. Activity similar to ß-thujaplicin has tropolone and its derivatives, which are not present nature. Due to the high scientific and practical interest, synthetic ß-thujaplicin and other troponoids have been produced for many years. In this review, the major biological effects of troponoids, mostly ß-thujaplicin and tropolone, on tyrosinase and polyphenol oxidase activity, ethylene production, antibacterial, antifungal and insecticidal activities, and biotransformation of ß-thujaplicin by cultured plant cells are presented. Accumulation of ß-thujaplicin and related troponoids has been shown in cell cultures of Cupressus lusitanica and other species of Cupressaceae. The biosynthetic pathway of the troponoids in plants, bacteria and fungi has been also briefly described

Alleviation of internal browning in pineapple fruit by peduncle infiltration with solutions of calcium chloride or strontium chloride under mild chilling storage

The development and control of internal browning (IB, a form of chilling injury) were studied in fruit of two commercial cultivars of pineapples. The symptoms develop in tissues surrounding the core when the fruit are stored at <15 °C for several weeks. It was found that core and the fruitlets of fruit of 'Smooth Cayenne' and 'Trad-Srithong' could be effectively infiltrated with water soluble carmoisine dye or salt solutions by transpiration via the peduncle over three days at storage temperatures of 8, 13, and 20 °C. IB was more severe in 'Trad-Srithong' than in 'Smooth Cayenne' fruit particularly at 8 °C. Infiltration via the peduncle increased calcium or strontium concentrations in the core and adjacent flesh tissue and reduced IB in 'Trad-Srithong' stored at 13 °C. There were no differences in severity of IB between green and quarter ripe fruit. Infiltration with calcium or strontium through the peduncle was more effective when the treatment was applied to freshly harvested fruit under mild chilling conditions

Measurement of mango firmness by non-destructive limited compression technique

Thai mango 'Nam Dok Mai Si-Thong' has an attractive golden yellow skin colour even in immature fruit, not ready for consumption. Firmness becomes an important quality attribute to assess the ripening stage of the fruit during storage. In this study, the possibility of a non-destructive method using a texture analyser for assessing the firmness behaviour during storage was investigated in three different experiments for (1) probe selection, (2) distance selection using the selected probe and (3) evaluation of the selected probe and distance on mango quality. The results revealed that an aluminium flat probe with 35 mm diameter is a suitable probe for measurement. Limited distance compression at 1 mm was selected since that combination did not leave any compression marks on the fully ripened mangoes. Evaluation of mango quality attributes obtained by this technique could be used to assess non-destructively the firmness behaviour of the mango fruit during storage. The technique can be used to monitor the firmness of mango fruit on an individual basis, using the same fruit in successive assessments. Non-linear indexed regression can be applied to extract information on the behaviour and variation of firmness of individual mangoes. Obtained explained parts (R2 adj) frequently are well over 90%.</p