Antibacterial activity of carob (Ceratonia siliqua L.) extracts against phytopathogenic bacteria Pectobacterium atrosepticum

Ceratonia Siliqua L: A Natural Compound with Big Impact on Male Reproductive System

Herbal products with antioxidant properties have gained attention for their potential impact on male reproductive health. One such botanical, Ceratonia siliqua (commonly known as carob), has been empirically used by infertile men in Iran and Turkey. Carob, a pod-bearing tree native to the Mediterranean, exhibits promising therapeutic potential for various aspects of male reproductive health. Carob consumption may positively affect sperm count, motility, and morphology in infertile men. The proposed mechanisms involve antioxidant activity, improved blood flow, and enhanced energy production within sperm. Carob's richness in antioxidants like polyphenols and flavonoids might counteract oxidative stress, a major contributor to sperm dysfunction. Carob may influence male sex hormones by potentially stimulating testosterone production and inhibiting estrogen conversion. While carob demonstrates promise as a natural supplement for male fertility, more robust research is necessary to solidify its therapeutic role. This exploration could pave the way for the development of novel dietary or nutraceutical interventions to address male infertility. While preliminary research suggests positive effects on sperm health and potential hormonal influence, robust clinical trials are needed to solidify carob's therapeutic efficacy. This exploration paves the way for future research on carob as a natural supplement and potentially opens doors for novel dietary or nutraceutical interventions to address male infertility.

Bioprotection of Olive Trees Against Verticillium Wilt by Pomegranate and Carob Extracts

Bioprotection through the use of plant extracts is an environmentally friendly strategy in crop protection. Effective control of Verticillium wilt of olive (Olea europaea; VWO), caused by Verticillium dahliae, has proven challenging because of the ineffectiveness of chemicals, which makes it necessary to search for new control tools. Thus, the aim of this study was to evaluate the effect of pomegranate (Punica granatum) and carob (Ceratonia siliqua) extracts on VWO. Extracts derived from pomegranate peels and carob pods and leaves were obtained using ethanol, methanol, or ethyl acetate as a solvent. A targeted analysis of their metabolite composition was performed using QTRAP ultrahigh-performance liquid chromatography with mass spectrometry. Remarkably, gallic acid was detected in all extracts at a high concentration. The effect of the extracts on the mycelial growth and on the germination of conidia and microsclerotia of V. dahliae was evaluated by in vitro sensitivity tests at various doses: 0 (control), 3, 30, 300, and 3,000 mg of extract/liter. Extracts obtained with ethanol or methanol significantly reduced the viability of V. dahliae structures when applied at the highest dose, while those obtained with ethyl acetate were ineffective across all doses. The most effective extracts, as determined in vitro, were then evaluated against the disease in olive plants. Potted plants of the cultivar Picual were treated by spraying (foliar application) or irrigation (root application) of extracts at 3,000 mg/liter, followed by inoculation with V. dahliae. The results indicated that foliar applications were ineffective, while root treatments with pomegranate peel or carob leaf extracts were more effective in reducing disease severity, regardless of the solvent, compared with that of the untreated control.

Carob (Ceratonia siliqua L.), Pharmacological and Phytochemical Activities of Neglected Legume of the Mediterranean Basin, as Functional Food

Carob (Ceratonia siliqua L.) has been widely cultivated in different parts of the world, particularly in the Mediterranean region, and the tree belongs to the family Leguminosae. Several studies have indicated that carobs and their products can improve human health and help prevent different specific chronic diseases. Carob can considered as functional food due to its high content in dietary fibers, low-fat content, and high content of minerals. Its fruit is a pod containing 10%-20% seeds, and the pods consist of sugars, proteins, crude fibers, minerals, vitamins, polyphenols, vitamins, and lipids. In many countries in the Middle east, carob is mainly used to prepare as a traditional drink and some kinds of confectioneries. The powders can be utilized to prepare carob juice concentrate. The systematic review of documents from clinical trials and scientific societies dedicated to traditional medicine in China has been carried out. The goal of this review article is a survey of chemical compounds, and pharmaceutical benefits of carob, especially by considering traditional medicinal sciences. Moreover, clinical trials research promotes studies to highlight and focus on the scope of application of traditional medicinal science in the growing system of medicine.

Nutritional, biochemical, and clinical applications of carob: A review

Carob is botanically called as Ceratonia siliqua and belongs to the Legumes family. The fruit is derived from hermaphrodite trees and hard in shape. The carob contains high sugar contents in pulp, fat in seed and minerals like potassium, calcium, and phosphorus are present in pods. Polyphenols and antioxidants are abundant in leaves and pods. It can be used for enhancing human health due to its high nutritional profile. Carob gum is used in the pharmaceutical industry in the form of pomades, anti-celiac ingredients, pills, and dental paste. The clinical carob can aid as an anti-cancer, anti-reflux, anti-diabetic, anti-diarrheal, anti-hyperlipidemia, anti-bacterial, anti-microbial, and anti-fungal. Nowadays, carob seeds are being used as an alternative to cocoa powder in food items whereas the leaves, pods, and seeds of carob are also historically used as food for animal feed. However, these parts of carob are available in markets with reasonable prices. Carob production, though with a rising contribution, contributes to the local economy. In this sense, we can incorporate knowledge on the chemical properties and the biological effect of carob fruits on human health. In this study, the supportive and health-promoting impacts of carob are discussed along with the clinical testing obtained from natural constituents of carob. In addition, further studies can be performed to extract and separate polyphenols and antioxidant potential for the development of functional that play a valuable role in pharmaceutical and food sectors.

Exploring the Multi-Faceted Potential of Carob (Ceratonia siliqua var. Rahma) Leaves from Morocco: A Comprehensive Analysis of Polyphenols Profile, Antimicrobial Activity, Cytotoxicity against Breast Cancer Cell Lines, and Genotoxicity

The botanical species Ceratonia siliqua L., commonly referred to as the Carob tree, and locally as "L'Kharrûb", holds significance as an agro-sylvo-pastoral species, and is traditionally utilized in Morocco for treating a variety of ailments. This current investigation aims to ascertain the antioxidant, antimicrobial, and cytotoxic properties of the ethanolic extract of C. siliqua leaves (CSEE). Initially, we analyzed the chemical composition of CSEE through high-performance liquid chromatography with Diode-Array Detection (HPLC-DAD). Subsequently, we conducted various assessments, including DPPH scavenging capacity, β-carotene bleaching assay, ABTS scavenging, and total antioxidant capacity assays to evaluate the antioxidant activity of the extract. In this study, we investigated the antimicrobial properties of CSEE against five bacterial strains (two gram-positive, Staphylococcus aureus, and Enterococcus faecalis; and three gram-negative bacteria, Escherichia coli, Escherichia vekanda, and Pseudomonas aeruginosa) and two fungi (Candida albicans, and Geotrichum candidum). Additionally, we evaluated the cytotoxicity of CSEE on three human breast cancer cell lines (MCF-7, MDA-MB-231, and MDA-MB-436) and assessed the potential genotoxicity of the extract using the comet assay. Through HPLC-DAD analysis, we determined that phenolic acids and flavonoids were the primary constituents of the CSEE extract. The results of the DPPH test indicated a potent scavenging capacity of the extract with an IC₅₀ of 302.78 ± 7.55 µg/mL, which was comparable to that of ascorbic acid with an IC₅₀ of 260.24 ± 6.45 µg/mL. Similarly, the β-carotene test demonstrated an IC₅₀ of 352.06 ± 12.16 µg/mL, signifying the extract's potential to inhibit oxidative damage. The ABTS assay revealed IC₅₀ values of 48.13 ± 3.66 TE µmol/mL, indicating a strong ability of CSEE to scavenge ABTS radicals, and the TAC assay demonstrated an IC₅₀ value of 165 ± 7.66 µg AAE/mg. The results suggest that the CSEE extract had potent antioxidant activity. Regarding its antimicrobial activity, the CSEE extract was effective against all five tested bacterial strains, indicating its broad-spectrum antibacterial properties. However, it only showed moderate activity against the two tested fungal strains, suggesting it may not be as effective against fungi. The CSEE exhibited a noteworthy dose-dependent inhibitory activity against all the tested tumor cell lines in vitro. The extract did not induce DNA damage at the concentrations of 6.25, 12.5, 25, and 50 µg/mL, as assessed by the comet assay. However, the 100 µg/mL concentration of CSEE resulted in a significant genotoxic effect compared to the negative control. A computational analysis was conducted to determine the physicochemical and pharmacokinetic characteristics of the constituent molecules present in the extract. The Prediction of Activity Spectra of Substances (PASS) test was employed to forecast the potential biological activities of these molecules. Additionally, the toxicity of the molecules was evaluated using the Protox II webserver.

Essential Oils from Two Apiaceae Species as Potential Agents in Organic Crops Protection

Chemical composition and herbicidal, antifungal, antibacterial and molluscicidal activities of essential oils from Choukzerk, Eryngium triquetrum, and Alexander, Smyrnium olusatrum, from western Algeria were characterized. Capillary GC-FID and GC/MS were used to investigate chemical composition of both essential oils, and the antifungal, antibacterial, molluscicidal and herbicidal activities were determined by % inhibition. Collective essential oil of E. triquetrum was dominated by falcarinol (74.8%) and octane (5.6%). The collective essential oil of S. olusatrum was dominated by furanoeremophilone (31.5%), furanodiene+curzurene (19.3%) and (E)-β-caryophyllene (11%). The E. triquetrum oil was tested and a pure falcarinol (99%) showed virtuous herbicidal and antibacterial activities against potato blackleg disease, Pectobacterium atrosepticum, and Gram-negative soil bacterium, Pseudomonas cichorii (85 and 100% inhibition, respectively), and high ecotoxic activity against brine shrimp, Artemia salina, and the freshwater snail, Biomphalaria glabrata, with an IC₅₀ of 0.35 µg/mL and 0.61 µg/mL, respectively. Essential oil of S. olusatrum showed interesting antibacterial and ecotoxic activity and good herbicidal activity against watercress seeds, Lepidium sativum (74% inhibition of photosynthesis, 80% mortality on growth test on model watercress), while the furanoeremophilone isolated from the oil (99% pure) showed moderate herbicidal activity. Both oils showed excellent antifungal activity against Fusarium. Both oils and especially falcarinol demonstrated good potential as new biocontrol agents in organic crop protection.

Chemical characterization of carob seeds (Ceratonia siliqua L.) and use of different extraction techniques to promote its bioactivity

Nowadays, the use of carob (Ceratonia siliqua L.) is reduced to its seeds. In fact, the food additive E410, locust bean gum, is obtained from its endosperm. However, the available information regarding the bioactive potential of carob seeds is limited and, often, with poorly established terminologies, not allowing the reader to know if the studied samples included seedless or seeded samples. So, the present study intended to carry out a chemical characterization of carob seeds focused on their bioactive compounds and test their bioactive properties. Carob seeds proved to be a source of tocopherols and organic acids, including phenolic compounds. Its antioxidant potential was demonstrated in vitro, as well as its antimicrobial capacity. This work proves that carob seeds have other functions in addition to those associated with E410. Thus, another potential can be given to the locust bean seed, namely the function of food preservative.

The Beekeeping State and Inventory of Mellifero-Medicinal Plants in the North-Central of Morocco

This study aims to determine the diversity of melliferous plants and to recognize the state of beekeeping in the Fez-Meknes region in Morocco. We conducted a questionnaire for beekeepers that set up their hives in the prefectures and provinces of the region, and we have studied the pharmacological evidence of the most preferred plants by beekeepers to assess its medicinal values. The results indicate that honey, bee pollen, bee bread, royal jelly, propolis, bee wax, bee venom, and bee queens are produced in this region with different percentages, and 102 plants belonging to 32 families were obtained in the inventory of melliferous plants; the most represented families were Asteraceae and Lamiaceae (13.73% each) followed by Rosaceae (8.82%). Among these 102 plants identified, 79 plants provide nectar and pollen for bees, 16 plants provide only pollen, 3 plants provide only nectar, 35 plants are resinous, and 6 plants provide honeydew for bees. The outcome of this study will contribute to the valuation of melliferous plants and help to establish a practical guide for the development of the beekeeping sector as an agricultural economic approach.

Ceratonia siliqua (Carob) extract improved in vitro development of vitrified-warmed mouse germinal vesicle oocytes: assessment of possible mechanism

Oocyte banking is a vital step for safekeeping and spreading genetic resources of animals. It is also used for fertility preservation of human. Oocyte vitrification is closely related to the lower developmental competence which includes the cryo-injury arisen during vitrification. The aim of the present study was to evaluate the maturation, embryonic development and production of reactive oxygen species (ROS) of mice oocytes following the supplementation vitrification media with different concentrations of Ceratonia siliqua (carob) extracts. In this experimental study, germinal vesicle oocytes collected from 8 to 10 week-old female NMRI mice (30-40 gr) were randomly divided into six groups of vitrification media supplemented with 0 (control), 5, 10, 20, 30 and 50 µg/ml C. siliqua. After thawing, oocytes were put in an in vitro maturation medium (IVM) (α-MEM: Alpha Minimum Essential Medium). 3-4 and 24 h (hr) later, the oocyte nuclear maturity was checked. Standard in vitro fertilization was performed on the matured oocytes (MII), and embryonic development was followed. Extra- and intra-cellular ROS was measured in IVM medium after 24 h of oocyte incubation. The addition of 20 and 30 μg/ml C. siliqua extract to vitrification media improved normal morphology of warmed germinal vesicle (GV) oocytes, rate of germinal vesicle break down (GVBD), and metaphase 2 (MII) oocyte formation significantly (p < 0.05). Fertilization rate, (embryonic development to 2 cells stage, 4-8 cells stage, and > 8 cells stage increased in the 30 μg/ml C. siliqua group significantly (p < 0.05). Furthermore, supplementation of 30 μg/ml C. siliqua in vitrification media significantly decreased extra- and intra-cellular of ROS as well as embryonic fragmentation (p < 0.05). In conclusion, supplementation of GV oocyte vitrification media with carob extract improved maturation, fertilization, and embryonic development rate and decreased extra- and intra-cellular ROS levels.

Fatty Acids from Hermetia illucens Larvae Fat Inhibit the Proliferation and Growth of Actual Phytopathogens

The rapid increase of plant diseases caused by bacterial phytopathogens calls for an urgent search for new antibacterials. Antimicrobial compounds of natural origin stand up as frontiers in the attempts of the antibiotic overuse replacement. With this in mind, the Hermetia illucens (H. illucens) larvae have recently gained attention as a promising approach to fulfill this need. This study aimed to isolate the active constituents of H. illucens larvae fat and to estimate its antimicrobial capacity. We discovered the best composition of extracting solution retaining the pronounced antimicrobial activity of the extract. Using gas chromatography-mass spectrometry (GC-MS), we identified the unique natural array of fatty acids as the major constituents of the acidified water-methanol extract (AWME) as having new antimicrobial potency. In standard turbidimetric assay, the minimum inhibitory concentration (MIC) of the AWME was 0.78 mg/mL after 24 h of incubation for all five tested phytopathogenic bacteria strains: Pantoea agglomerans, Xanthomonas campestris, Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, and Dickeya solani. The minimum bactericidal concentration (MBC) ranged from 0.78 to 1.56 mg/mL against all tested strains after 24 h of incubation. The inhibition zone size of AWME (INZ) at 50 mg/mL concentration was in the range 12.2 ± 0.56 to 19.0 ± 0.28 mm, while zone size for the positive control (penicillin-streptomycin) (5000 IU/mL-5000 µg/mL) was in the scale of 20.63 ± 0.53 to 24.0 ± 0.35 mm as revealed by standard disk diffusion assay. For the first time, our findings indicated the substantial antibacterial potential of AWME of H. illucens larvae fat against these actual phytopathogens, thus paving the way for further research to determine the mechanism of action in crop protection.

Biological Activities of Aqueous Extracts from Carob Plant (Ceratonia siliqua L.) by Antioxidant, Analgesic and Proapoptotic Properties Evaluation

The present work describes the volatile compounds profile and phytochemical content of Ceratonia siliqua L. Fifty different components have been identified. Among them, three constituents are shared i.e., 2-methlybutanoic acid, methyl hexanoate and limonene by different common carob preparations: pulp decoction (PD), seeds decoction (SD) and Rob, a sweet syrup extracted from the pulp of the carob pod. Each extract exhibits different volatile aromatic emission profiles. The antioxidant activity of the extracts was evaluated using three methods, DPPH, ABTS and FRAP, producing a dose-dependent response. The IC_50, when determined by FRAP, gave the lowest values (0.66 ± 0.01, 0.73 ± 0.05 and 0.55 ± 0.00 mg/mL PD, SD and Rob, respectively). The nociception essay, after intraperitoneal injection of acetic acid in mice, demonstrated that Rob, pulp and seeds decoction extracts showed an efficient inhibition of writhes over time, with persistence over 30 min. The SD decoction revealed the highest efficacy in decreasing the writhing reflex (90.3 ± 1.2%; p < 0.001). Furthermore, the proapoptotic activity of SD against three human cell line, THP-1, MCF-7 and LOVO, evaluated by flow cytometry, showed a significantly stronger proapoptotic activity on colon cancer (LOVO) than on the other cell lines, a phenomenon known as phenotypic selectivity.

A closed-loop biorefinery approach for polyhydroxybutyrate (PHB) production using sugars from carob pods as the sole raw material and downstream processing using the co-product lignin

A novel closed-loop biorefinery model using carob pods as the feed material was developed for PHB production. The carob pods were delignified, and as the second step, sugars present in the delignified carob pods were extracted using water. Ralstonia eutropha and Bacillus megaterium were cultivated on the carob pod extract and its performance was evaluated using Taguchi experimental design. R. eutropha outperformed the B. megaterium in terms of its capability to grow at a maximum initial sugar concentration of 40 g L^-1 with a maximum PHB production of 12.2 g L^-1. Finally, the concentrated lignin from the first step was diluted with different proportion of chloroform to extract PHB from the bacterial biomass. The PHB yield and purity obtained were more than 90% respectively using either R. eutropha or B. megaterium. Properties of the PHB produced in this study were examined to establish its application potential.

An in vitro study of the effect of carob (Ceratonia siliqua L.) leaf extracts on gilthead seabream (Sparus aurata L.) leucocyte activities. Antioxidant, cytotoxic and bactericidal properties

Carob leaves, the main residues of the carob tree, were investigated as a renewable and abundant source of bioactive compounds for fish aquaculture. Aqueous and ethanolic extracts obtained from carob leaves were characterized in terms of biochemical composition, antiradical and cytotoxic effects and immunostimulant and antibacterial activities. The ethanolic extract showed higher levels of total phenolics, flavonoids and condensed tannins and higher antioxidant activity than the aqueous extract. No significant immunostimulant effects were observed on gilthead seabream (Sparus aurata) head kidney leucocytes (viability, phagocytosis and respiratory burst activities and peroxidase content) after incubation for 24 h with different extracts. Furthermore, the ethanolic extracts used at 0.5, 0.75 and 1 mg mL^-1 and aqueous extracts at 1 g mL^-1 had a cytotoxic effect on PLHC-1 cells. When the bactericidal activity was tested against three fish pathogenic bacteria (Vibrio harveyi, Vibrio anguillarum and Photobacterium damselae) notable activity of the different extracts was detected against P. damselae at all three concentrations. A similar effect was demonstrated against V. haryeri when ethanolic extracts were used in the same range of concentrations. This work demonstrates interesting in vitro effects of carob leaf extracts and suggests it could be used as an alternative to chemical compounds with farmed fish. The concentration and nature of the extracts were very important in terms of any positive results.

In vitro application of Ceratonia siliqua improved sperm parameters and chromatin quality after vitrifacation in normozoospermic aged men

Background

Vitrification is the main technique in the assisted reproductive technique (ART) labs. Sperm vitrification exposes sperm to damage. The aim of the present study was to evaluate the in vitro effect of Ceratonia siliqua (C. siliqua) application on sperm parameters and chromatin quality in normozoospermic aged men. Semen samples (n = 40) were collected from normozoospermic men over 45 years old. Each specimen was divided into four aliquots to form the subsequent groups: fresh (group I), vitrification without treatment (group II), vitrification with the medium supplemented by 20 μg/ml C. siliqua (group III), and vitrification with the thawing medium supplemented by 20 μg/ml C. siliqua (group IV). Sperm progressive motility, normal morphology and viability were assessed. Also, sperm chromatin quality was evaluated by aniline blue (AB), toluidine blue (TB), and sperm chromatin dispersion (SCD) staining.

Results

Vitrification caused a significant decrease in sperm progressive motility, normal morphology and viability as well as chromatin quality compared to fresh samples (p < 0.05). Supplementation of vitrification/thawing medium with C. siliqua significantly improved sperm progressive motility, normal morphology, viability, and chromatin quality compared to vitrification without any supplementation (p < 0.05).

Conclusions

The study showed that C. siliqua can improve the detrimental effect of vitrification on sperm parameters and chromatin quality of normozoospermic aged men.

Effects of Carob Fruit Extract on Spermatogenesis, Antioxidant Status, and Apoptosis in Adult Male Mice

Background: Certain plants stimulate spermatogenesis and increase fertility; in contrast, some plants arrest the spermatogenesis cycle. Ceratonia siliqua is an herb plant with a strong antioxidant property. The aim of this study was to evaluate the effects of carob fruit extract on spermatogenesis, testicular apoptosis, and oxidative stress in adult male mice. Methods: Forty adult male mice were randomly divided into five groups: control, sham, and carob 1–3. The sham group was injected with normal saline and the carob 1–3 groups were injected with 200, 400, and 800 mg/kg of the carob fruit extract intraperitoneally for 14 days, respectively. At the end of the injection period, spermatogenesis, testicular apoptosis, and oxidative stress were examined. Results: The sperm parameters increased in the mice that received 200 mg/kg of carob compared to the sham group (p <0.05). There was a significant increase in the weight index of the epididymis in the carob 3 group in comparison to the sham group (p = 0.01). The number of positive tunnel cells was not statistically significant between different groups (p>0.05). The level of malondialdehyde decreased in the carob 1 and carob 3 groups, but this reduction was not statistically significant (p > 0.05). In addition, the statistical analysis showed a significant difference in the mean superoxide dismutase levels in the carob 2 and carob 3 groups in comparison to the sham group (p ≤ 0.001). The statistical analysis showed a significant increase in the mean level of the catalase enzyme in the carob 1 group in comparison to the sham (p = 0.02), and carob 2 groups (p = 0.008). Conclusion: The administration of 200 mg of the carob fruit extract for 14 days increased the testicular index as well as sperm parameters and decreased the level of oxidative stress in the testicular tissue of adult mice.

Does supplementation of sperm freezing/thawing media with Ceratonia siliqua improve detrimental effect of cryopreservation on sperm parameters and chromatin quality in normozoospermic specimens?

Human sperm banking is an important procedure in the assisted reproductive technique centers. It entails sperm damage. The aim of this study was to investigate beneficial effect of Ceratonia siliqua (C. siliqua) supplement in freezing/thawing media on post thaw sperm parameters and sperm chromatin quality in normozoospermic samples. Forty normozoospermic specimens were included in this prospective study. Each sample was divided into ten groups. In groups one to five, 0 (as control group) 5, 10, 20 and 30 µg/ml C. siliqua were added to freezing medium and in groups six to ten, similar concentration of C. siliqua were added to thawing medium for 30 min incubation. Sperm concentration, progressive motility, normal morphology, viability, aniline blue (AB), toluidine blue (TB) and sperm chromatin dispersion (SCD) staining tests were evaluated before vitrification and after thawing. The results showed that 10 and 20 µg/ml supplementation of C. siliqua in freezing/thawing media significantly increased progressive motility, normal morphology and viability of sperm (p < 0.05) as well as decreased AB, TB and SCD (p < 0.05). Also, 20 µg/ml had significantly higher improvement compared to 10 µg/ml C. siliqua (p < 0.05). The present study showed that C. siliqua supplemented freezing/thawing media can improve sperm quality of normozoospermic samples after freezing/thawing.

Variation in Ceratonia siliqua pod metabolome in context of its different geographical origin, ripening stage and roasting process

Carob is a legume tree of a considerable commercial importance for the flavor and sweet industry. In this context, it is cultivated mostly for its pods, which are known for their nutritive value and multiple health benefits. However, metabolite patterns, underlying these properties are still mostly uncharacterized. In this study, the role of geographical origin, ontogenetic changes and thermal processing on the Ceratonia siliqua pod metabolome was assessed by mass spectrometry (MS)-based metabolomics. Thereby, a total of 70 fruits primary metabolites, represented mainly by carbohydrates, organic and amino acids were detected. Analysis of secondary bioactive metabolites assessed by ultra-high-performance liquid chromatography-electrospray ionization high resolution mass spectrometry (UHPLC-ESI-HR-MS) revealed in total 83 signals. The major signals, most significantly contributing in discrimination of C. siliqua specimens were assigned to tannins and flavonoids. PCA models derived from either UHPLC-MS or GC-MS proved to be powerful tools for discrimination of C. siliqua specimens.

Siliquapyranone: A Tannic Acid Tetrahydropyran-2-one Isolated from the Leaves of Carob (Ceratonia siliqua) by Pressurised Hot Water Extraction

Studies of the phytochemistry of carob (Ceratonia siliqua) leaf material are extremely limited. This report features the second natural product isolation study of carob leaves and the first such investigation of C. siliqua grown in Australia. Investigation of leaf material from seven carob cultivars using pressurised hot water extraction (PHWE) revealed the presence of high levels of myricitrin, d-pinitol, and sucrose in addition to the previously unreported natural product siliquapyranone {(2R,3R,4S,5R,6R)-5-hydroxy-6-(hydroxymethyl)-2-(((2S,4S)-2-methyl-6-oxotetrahydro-2H-pyran-4-yl)oxy)tetrahydro-2H-pyran-3,4-diyl bis(3,4,5-trihydroxybenzoate)}. Siliquapyranone represents a biosynthetic fusion of conventional 2,3-gallate esters on a β-glucose tannin with a hydroxytetrahydro-2H-pyran-2-one-related non-tannin tetrahydropyran-2-one, parasorboside. Preliminary biological testing indicates that siliquapyranone exhibits weak activity against both tumour and normal cell lines. This suggests that, like most tannins and parasorboside, siliquapyranone may act as an antifeedant.

Use of FTIR spectroscopy and chemometrics for the classification of carobs origin

Carob samples from seven different Mediterranean countries (Cyprus, Greece, Italy, Spain, Turkey, Jordan and Palestine) were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Seed and flesh samples of indigenous and foreign cultivars, both authentic and commercial, were examined. The spectra were recorded in transmittance mode from KBr pellets. The data were compressed and further processed statistically using multivariate chemometric techniques, including Principal Component Analysis (PCA), Cluster Analysis (CA), Partial Least Squares (PLS) and Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA). Specifically, unsupervised PCA framed the importance of the variety of carobs, while supervised analysis highlighted the contribution of the geographical origin. Best classification models were achieved with PLS regression on first derivative spectra, giving an overall correct classification. Thus, the applied methodology enabled the differentiation of carobs flesh and seed per their origin. Our results appear to suggest that this method is a rapid and powerful tool for the successful discrimination of carobs origin and type.