ABSTRACT
This work explored the compositions of a crude extract of peels of Citrus x aurantium using a gas chromatography-mass spectrometry (GC-MS) technique. The crude extract of peels of C. × aurantium was analyzed by GC-MS revealing the presence of limonene as the major compound, accounting for 93.7% of the total. Virucidal activity of the oil of C. x aurantium peels against influenza A virus H1N1 was evaluated by the ASTM E1053-20 method. Moreover, the virucidal activity was also investigated of D-limonene, the major terpene in essential oils of C. x aurantium, and its enantiomer L-limonene. The essential oil of the C. x aurantium peels produced a log reduction of 1.9 to 2.0, accounting for 99% reduction of the virus, while D- and L-limonene exhibited virucidal activity with a log reduction of 3.70 to 4.32 at concentrations of 125 and 250.0 µg/mL, thus reducing the virus by 99.99%. Previous work found that D-limonene exhibited antiviral activity against herpes simplex virus, but L-limonene, an enantiomer of D-limonene, has never been reported for antiviral activity. This work demonstrates the antiviral activity of L-limonene for the first time. Moreover, this work suggests that concentrations of 0.0125% to 0.025% of either D- or L-limonene can possibly be used as a disinfectant against viruses, probably in the form of essential oil sprays, which may be useful disinfectants against the airborne transmission of viruses, such as influenza and COVID-19.
ABSTRACT
Camphor (C10H16O) is a white crystalline solid exist in enantiomeric form R and S camphor. It is a terpenoid obtained from turpentine oil. Synthetically it is synthesized by catalytic process as alpha pinene. Naturally camphor is obtained by steam distillation of woods of Cinnamomum camphora tree, also known as Camphor tree, camphor laure and camphor wood. Camphor has many pharmacological properties. It acts as antiviral, anticancerous, antimicrobial, insecticidal, anticoccidial, anti-nociceptive and antitussive drug. In addition, it can be used as skin penetrating enhancer. Camphor gives a soothing and cooling effect, which helps to reduce pain. The reason behind its soothing effect is camphor act as a counter-irritant by activating heat sensitive transient receptor potential vanilloid subtype 1 and transient receptor potential vanilloid subtype 3 receptors and inhibits the transient receptor potential melastatin-subfamily member 8 receptor. As a result, these receptors provide a sensation of scalding heat and pain (nociception) and could be used to treat neuropathic pain associated with multiple sclerosis, chemotherapy, or amputation, as well as pain associated with the inflammatory response of damaged tissue such as in osteoarthritis. Camphor has a history of epidemics cure. During leishmaniosis (kala-azar) pandemic in 14th century, camphor was used as fumigant to control the spread of plague in European countries. In 19th century when cholera, small pox and influenza spreads, camphor was used as mothballs in Indian subcontinent as a (cough reliever) agent. During 18th century Russian influenza “flu pandemic” founder of Homeopathy Hahnemann in 1831, published his research work on camphor and suggested camphor as a “divine remedy” for influenza given in extremely small doses. In the same year, several companies launched to sell menthol rub as natural rub ointment consisting camphor as prevention measures for spread of influenza. As the recent epidemic of COVID-19 arises, prevention and control of spread of disease is an alarming issue. This article covered the glimpse of uses and importance of camphor in the history of epidemic cure.
ABSTRACT
The essential oil (EO) of Salvia leucantha Cav. was isolated by steam distillation of the aerial parts collected in the South of Ecuador. Its physical properties were evaluated and the chemical composition of the oil was determined by GC-MS and GC-FID analyses using two chromatographic columns, DB-5ms and HP-INNOWax. Six major compounds were identified, namely, the sesquiterpenes 6.9-guaiadiene (19.14%), (E)-caryophyllene (16.80%), germacrene D (10.22%), (E)-ß-farnesene (10.00%), and bicyclogermacrene (7.52%), and the monoterpenoid bornyl acetate (14.74%). Furthermore, four pairs of enantiomers were determined by enantioselective GC-MS of the essential oil. (-)-germacrene D and (+)-α-pinene showed the highest enantiomeric excess (ee%). In an in vitro assay, the essential oil demonstrated an interesting inhibitory activity of the enzyme butyrylcholinesterase (BuChE), with an IC50 = 32.60 µg/mL, which is the highest determined for a Salvia species. In contrast, the oil was weakly active against acetylcholinesterase (AChE) with an IC50 > 250 µg/mL.