Glucosinolates, Glycosidically Bound Volatiles and Antimicrobial Activity of Brassica oleraceae Var. Botrytis, (Soultany Cultivar)

Background: Egyptian cauliflower Brassica oleracea, L. var. Botrytis L. Soultany cultivar, is an important edible plant in Mediterranean countries. Only a few researches were focused on antimicrobial activity of its volatiles and glucosinolates. Objective: To evaluate the antimicrobial activity of volatiles and glucosinolates of Egyptian Cauliflower and identify them by GC/MS and HPLC/MS designs. Materials and Methods: The semi-volatile and volatile constituents of were extracted by hydrodistillation from leaves, stems and inflorescences, using a Likens –Nickerson-type apparatus. The extracts from fresh and frozen vegetables were investigated by GC/MS and HPLC/MS. the volatile samples containing glucosinolate degradation products were evaluated for antimicrobial activity using the disc diffusion method. Results: From the fresh leaves extract, a total of 49 compounds were identified, representing 98.79% of the oil. The major constituent was found to be hex-3(Z)-enol (18.86%). From fresh disrupted inflorescence tissues of Egyptian cauliflower 45 compounds were detected, representing 93.37% of the extract. Nonacosane and 11-methoxy   benz(a)anthracene-7,12-dione   were   identified  as  major constituents   of   the hydrodistillation products, representing, respectively, 17.7 and 8.31% of the volatiles.   From frozen inflorescence tissues, dimethyl trisulfide and butylated hydroxy toluene were detected as predominant components representing 15.88 and 9.69% respectively. In the latter, hex-3(Z)-enol was not found to be the major constituent as happened in fresh leaves, but representing 3.88%. From fresh stem tissues, dimethyl trisulphide was detected as major constituent representing a percentage (24.06%) more than present in frozen inflorescence tissues. Twenty two compounds were identified by triple quad HPLC/MS. Volatile samples expressed a wide range of growth inhibition activity against both Gram-positive and Gram-negative bacteria and fungi, showing the highest inhibitory effects against E .coli and K. pneumonia strains. Conclusion: Hydrodistilled compounds present in the stems, leaves and inflorescence tissues of this cultivar has a highly promising antimicrobial activity. Keywords: Cauliflower, Brassica oleraceae, Glucosinolates, GC/MS, HPLC/MS, Antimicrobial activity.

Induction of antibacterial metabolites by co-cultivation of two Red-Sea-sponge-associated actinomycetes <i>Micromonospora</i> sp. UR56 and <i>Actinokinespora</i> sp. EG49

Liquid chromatography coupled with high resolution mass spectrometry (LC-HRESMS)-assisted metabolomic profiling of two sponge-associated actinomycetes, Micromonospora sp. UR56 and Actinokineospora sp. EG49, revealed that the co-culture of these two actinomycetes induced the accumulation of metabolites that were not traced in their axenic cultures. Dereplication suggested that phenazine-derived compounds were the main induced metabolites. Hence, following large-scale co-fermentation, the major induced metabolites were isolated and structurally characterized as the already known dimethyl phenazine-1,6-dicarboxylate (1), phenazine-1,6-dicarboxylic acid mono methyl ester (phencomycin; 2), phenazine-1-carboxylic acid (tubermycin; 3), N-(2-hydroxyphenyl)-acetamide (9), and p-anisamide (10). Subsequently, the antibacterial, antibiofilm, and cytotoxic properties of these metabolites (1&ndash;3, 9, and 10) were determined in vitro. All the tested compounds except 9 showed high to moderate antibacterial and antibiofilm activities, whereas their cytotoxic effects were modest. Testing against Staphylococcus DNA gyrase-B and pyruvate kinase as possible molecular targets together with binding mode studies showed that compounds 1&ndash;3 could exert their bacterial inhibitory activities through the inhibition of both enzymes. Moreover, their structural differences, particularly the substitution at C-1 and C-6, played a crucial role in the determination of their inhibitory spectra and potency. In conclusion, the present study highlighted that microbial co-cultivation is an efficient tool for the discovery of new antimicrobial candidates and indicated phenazines as potential lead compounds for further development as antibiotic scaffold

¹H-NMR metabolic profiling, antioxidant activity, and docking study of common medicinal plant-derived honey

The purpose of this investigation was to determine &sup1;H-NMR profiling and antioxidant activity of the most common types of honey, namely, citrus honey (HC1) (Morcott tangerine L. and Jaffa orange L.), marjoram honey (HM1) (Origanum majorana L.), and clover honey (HT1) (Trifolium alexandrinum L.), compared to their secondary metabolites (HC2, HM2, HT2, respectively). By using a &sup1;H-NMR-based metabolomic technique, PCA, and PLS-DA multivariate analysis, we found that HC2, HM2, HC1, and HM1 were clustered together. However, HT1 and HT2 were quite far from these and each other. This indicated that HC1, HM1, HC2, and HM2 have similar chemical compositions, while HT1 and HT2 were unique in their chemical profiles. Antioxidation potentials were determined colorimetrically for scavenging activities against DPPH, ABTS, ORAC, 5-LOX, and metal chelating activity in all honey extract samples and their secondary metabolites. Our results revealed that HC2 and HM2 possessed more antioxidant activities than HT2 in vitro. HC2 demonstrated the highest antioxidant effect in all assays, followed by HM2 (DPPH assay: IC50 2.91, 10.7 &mu;g/mL; ABTS assay: 431.2, 210.24 at 50 ug/mL Trolox equivalent; ORAC assay: 259.5, 234.8 at 50 ug/mL Trolox equivalent; 5-LOX screening assay/IC50: 2.293, 6.136 ug/mL; and metal chelating activity at 50 ug/mL: 73.34526%, 63.75881% inhibition). We suggest that the presence of some secondary metabolites in HC and HM, such as hesperetin, linalool, and caffeic acid, increased the antioxidant activity in citrus and marjoram compared to clover honey

The genus <i>Micromonospora</i> as a model microorganism for bioactive natural product discovery

This review covers the development of the genus Micromonospora as a model for natural product research and the timeline of discovery progress from the classical bioassay-guided approaches through the application of genome mining and genetic engineering techniques that target specific products. It focuses on the reported chemical structures along with their biological activities and the synthetic and biosynthetic studies they have inspired. This survey summarizes the extraordinary biosynthetic diversity that can emerge from a widely distributed actinomycete genus and supports future efforts to explore under-explored species in the search for novel natural products

Management of hepatitis C virus genotype 4: recommendations of an international expert panel.

HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in the world, it has not been the subject of widespread research. Therefore, this document, drafted by a panel of international experts, aimed to review current knowledge on the epidemiology, natural history, clinical, histological features, and treatment of HCV-4 infections

Influence of black tea on Streptococcus mutans and Lactobacillus levels in saliva in a Saudi cohort

الملخص: أهداف البحث: يرتبط تسوس الأسنان مع ارتفاع عدد المستعمرات من المكورات العقدية الطافرة والملبنة وانخفاض قدرة اللعاب على تخفيف تركيز هذه المستعمرات. تهدف هذه الدراسة لتقييم النشاط المضاد للميكروبات للشاي الأسود على البكتريا المسببة لتسوس الأسنان من المكورات العقدية الطافرة والملبنة. وتم قياس النشاط المضاد للميكروبات بعدد وحدات تشكيل المستعمرات. تمت دراسة العلاقة بين هذه العوامل قبل تناول الشاي وبعد ساعة وساعتين من شرب الشاي في مجموعة من البالغين في المدينة المنورة. طرق البحث: أجريت دراسة تجريبية مستقبلية متعددة مراحل المتابعة لتقييم النشاط المضاد للميكروبات للشاي الأسود على البكتريا المسببة لتسوس الأسنان من المكورات العقدية الطافرة والملبنة. تم الحصول على عينات اللعاب بدون أي محفزات من المشاركين (قبل وبعد شرب الشاي على الفور بعد ساعة واحدة) عن طريق البصق إلى أوعية معقمة. وأخذت العينات إلى المختبر مباشرة من أجل وضعها في محضن لمعادلة درجة الحرارة ثم العد للمستعمرات المتكونة لاحقا. تم حساب أعداد للمكورات العقدية الطافرة والملبنة من اللعاب باستخدام اختبار قياس مخاطر التسوس. النتائج: أجري البحث على ٢١ مشاركا، ١٣ من الذكور و٨ من الإناث الذين كان متوسط أعمارهم ٣٢.٦ ± ٨.٠٢. لم يكن للشاي الأسود تأثير معنوي على تقليل التعداد البكتيري. الاستنتاجات: يمكن استنتاج أن الشاي الأسود أظهر تأثيرا مضادا للميكروبات ضئيل ضد المكورات العقدية الطافرة والملبنة. Abstract: Objectives: Dental caries are associated with high counts of Streptococcus mutans (SM) and Lactobacillus (LB) and low saliva buffering capacity (BC). This study aimed to evaluate the antimicrobial activity of black tea on salivary cariogenic microflora, SM and LB species in an adult population. Antimicrobial activity was measured from the number of colony forming units (CFUs) of SM and LB, and BC of saliva. Methods: In this prospective experimental study, unstimulated saliva samples were acquired from the participants before, immediately after, and 1 h after drinking tea by collecting saliva in sterilised containers. Samples were taken to the laboratory for incubation and subsequent counting. SM and LB counts and BC of saliva were calculated using the caries risk test (CRT). Results: A total of 21 participants, 13 males and 8 females, with a mean age of 32.6 ± 8.02, were recruited in this study. Black tea had no significant effect on reducing the cariogenic bacterial counts (p > 0.05). Conclusion: Based on this study, it can be deduced that black tea exhibits an insignificant antimicrobial effect against Streptococcus mutans and Lactobacillus bacteria. الكلمات المفتاحية: الشاي الأسود, البكتيريا المسببة للتسوس, المكورات العقدية الطافرة, الملبنة, Keywords: Black tea, Cariogenic bacteria, Lactobacillus, Streptococcus mutan