Certain male fruit flies from the genera Bactrocera and Zeugodacus (Diptera: Tephritidae) actively forage for floral semiochemicals produced by some endemic Bulbophyllum orchids found in tropical and subtropical forests. These floral semiochemicals are largely classified as either phenylbutanoids (e.g., raspberry ketone (RK)) or phenylpropanoids (e.g., methyl eugenol (ME)). Zingerone (ZN) is a phenylbutanoid recently found that structurally resembles ME and RK, both of which are phytochemicals commonly used as male attractants in fruit fly control programmes. It was previously shown that feeding on ME and RK increased the mating success of certain tephritid fruit flies, specifically in B. dorsalis and B. tryoni males, respectively, through enhancement of sexual signaling. However, ZN, which acts as a metabolic enhancer to increase male courtship activity in B. tryoni, did not show the same effect. As fruit fly-phytochemical lure interactions are unique and species-specific phenomena, this study seeks to elucidate the ecological significance of ZN feeding to Zeugodacus tau in terms of sexual signaling. We demonstrate here that ZN feeding by Z. tau males enhanced female attraction and subsequent mating success by increasing male courtship, and the attractiveness of the sexual signals in both wind tunnel and semi-field cage bioassays. In addition, we also demonstrated temporal effects on male behaviour in relation to the amount of lure intake. However, feeding on ZN did not appear to affect the total time spent in copula for Z. tau. This is the first report showing an important role of ZN in increasing courtship activity as well as enhancement of sexual signaling in Z. tau males.
Males of certain Dacini fruit flies are strongly attracted to, and feed upon, plant secondary compounds such as methyl eugenol, raspberry ketone and zingerone. The consumed lure is generally found to induce physiological and behavioural changes that enhance the mating performance of lure-fed males. Male Bactrocera jarvisi respond strongly to zingerone from a young age, but only weakly respond to raspberry ketone. We hypothesized that this selective lure-response would be reflected in the physiological importance of the lure to the fly. We found that zingerone feeding by young males resulted in significantly greater mating success in competitive mating trials with lure-deprived flies, but the mating advantage was lost in older males. Lure dosage had a significant effect on the duration of the mating advantage, for example when fed 20 µg of zingerone, the advantage lasted only 1 day post-feeding, but when fed of 50 µg zingerone the advantage lasted 7 days. Raspberry ketone feeding did not confer any mating advantage to males except at one dosage (50 µg) for 1 day after feeding. When given a choice, B. jarvisi females preferred to mate with zingerone-fed versus to raspberry ketone-fed males. This study revealed lure, dosage and age of fly at time of lure administration are all important factors for maximising lure-enhanced fruit fly mating performance. These findings contribute to a better theoretical understanding of the evolution of fruit fly-lure interactions and may help improve fruit fly pest management via the Sterile Insect Technique through semiochemical-mediated enhancement of sterile male mating performance.
Molecules that target the deoxyribonucleic acid (DNA) minor groove are relatively sequence specific and they can be excellent carrier structures for cytotoxic chemotherapeutic compounds which can help to minimize side effects. Two novel isomeric derivatives of diaminobenzene Schiff base [N,N'-bis (2-hydroxy-3-methoxybenzylidene)-1,2-diaminobenzene (2MJ) and N,N'-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminobenzene (2MH)] were analyzed for their DNA minor groove binding (MGB) ability using viscometry, UV and fluorescence spectroscopy, computational modeling and clonogenic assay. The result shows that 2MJ and 2MH are strong DNA MGBs with the latter being more potent. 2MH can form interstrand hydrogen bond linkages at its oxygens with N3 of adenines. Changing the 2-hydroxy-3-methoxybenzylidene binding position to the 1,3 location on the diaminobenzene structure (2MJ) completely removed any viable hydrogen bond formation with the DNA and caused significant decrease in binding strength and minor groove binding potency. Neither compound showed any significant cytotoxicity towards human breast, colon or liver cancer cell lines.
Gingerols and shogaols are compounds found in ginger (Zingiber officinale Roscoe); shogaols are found in lower concentration than gingerols but exhibit higher biological activities. This work studied the effects of different drying methods including open sun drying (OSD) solar tunnel drying (STD) and hot air drying (HAD) with various temperature on the formation of six main active compounds in ginger rhizomes, namely 6-, 8-, and 10-gingerols and 6-, 8-, and 10-shogaols, as well as essential oil content. Antioxidant and antimicrobial activity of dried ginger was also evaluated. High performance liquid chromatography (HPLC) analysis showed that after HAD with variable temperature (120, 150 and 180 °C), contents of 6-, 8-, and 10-gingerols decreased, while contents of 6-, 8-, and 10-shogaol increased. High formation of 6-, 8-, and 10-shogaol contents were observed in HAD (at 150 °C for 6 h) followed by STD and OSD, respectively. OSD exhibited high content of essential oil followed by STD and HAD method. Ginger-treated with HAD exhibited the highest DPPH (IC50 of 57.8 mg/g DW) and FRAP (493.8 µM of Fe(II)/g DM) activity, compared to STD and OSD method. HAD ginger exhibited potent antimicrobial activity with lower minimum inhibition concentration (MIC) value against bacteria strains followed by STD and OSD, respectively. Ginger extracts showed more potent antimicrobial activity against Gram positive bacteria than Gram negative bacteria strains. Result of this study confirmed that conversion of gingerols to shogaols was significantly affected by different drying temperature and time. HAD at 150 °C for 6 h, provides a method for enhancing shogaols content in ginger rhizomes with improving antioxidant and antimicrobial activities.
Humans have been using natural products for medicinal use for ages. Natural products of therapeutic importance are compounds derived from plants, animals, or any microorganism. Ginger is also one of the most commonly used condiments and a natural drug in vogue. It is a traditional medicine, having some active ingredients used for the treatment of numerous diseases. During recent research on ginger, various ingredients like zingerone, shogaol, and paradol have been obtained from it. Zingerone (4-(4-hydroxy-3-methoxyphenyl)-2-butanone) is a nontoxic and inexpensive compound with varied pharmacological activities. It is the least pungent component of Zingiber officinale. Zingerone is absent in fresh ginger but cooking or heating transforms gingerol to zingerone. Zingerone closely related to vanillin from vanilla and eugenol from clove. Zingerone has potent anti-inflammatory, antidiabetic, antilipolytic, antidiarrhoeic, antispasmodic, and so forth properties. Besides, it displays the property of enhancing growth and immune stimulation. It behaves as appetite stimulant, anxiolytic, antithrombotic, radiation protective, and antimicrobial. Also, it inhibits the reactive nitrogen species which are important in causing Alzheimer's disease and many other disorders. This review is written to shed light on the various pharmacological properties of zingerone and its role in alleviating numerous human and animal diseases.