UHPLC-QQQ-MS and RP-HPLC Detection of Bioactive Alizarin and Scopoletin Metabolites from Morinda citrifolia Root Extracts and Their Antitubercular, Antibacterial, and Antioxidant Activities.

Morinda citrifolia is a medicinal plant that has been traditionally used in various therapeutic applications. All parts of M. citrifolia including fruits, leaves, stems, roots, and flowers contain various biologically active phytochemicals. This study aimed to evaluate the antitubercular, antibacterial, and antioxidant activities of M. citrifolia root extracts and spectroscopically analyze the bioactive metabolites. M. citrifolia root extracts were prepared via maceration. The minimum inhibitory concentration (MIC) for antitubercular activity, the inhibition zone for antibacterial activity, and the antioxidant activities in terms of half-maximal inhibitory concentration (IC50) values were determined. 1H-NMR, RP-HPLC, and UHPLC-QQQ-MS analyses were performed to evaluate the secondary metabolites. The results showed that the dichloromethane root extract exhibited relatively good inhibition of M. tuberculosis with an MIC value of 50 µg/mL. All extracts were mostly active against five tested bacterial strains. The ethanolic and dichloromethane root extracts showed the highest antioxidant power against DPPH (IC50 = 0.82 mg/mL) and NO (IC50 = 0.64 mg/mL) radicals, respectively. The 1H-NMR-based screening of the secondary metabolites of all M. citrifolia root extracts confirmed the presence of triterpenes, steroids, phenolics, flavonoids, tannins, and anthraquinones as major bioactive components. Alizarin and scopoletin were detected in the extracts via UHPLC-QQQ-MS, and the alizarin (0.552-3.227 g/100 g dry weight) and scopoletin (0.092-0.554 g/100 g dry weight) contents were quantified via RP-HPLC. The antimicrobial and antioxidant activities of M. citrifolia root extracts and the identification of the main bioactive ingredients are the initial studies that can be beneficial for further in vivo studies and biomedical applications of its bioactive compounds.

In Vitro Activities of Enantiopure and Racemic 1'-Acetoxychavicol Acetate against Clinical Isolates of Mycobacterium tuberculosis.

In the process of evaluating the effect of several plant extracts against Mycobacterium tuberculosis using the Microplate Alamar Blue Assay (MABA), an extract of Thai herb Alpinia galanga rhizome and its major component, 1'-acetoxychavicol acetate (ACA), exhibited marked anti-tuberculosis activity. The minimal inhibition concentrations (MICs) of the S-enantiomer of ACA (S-ACA) against M. tuberculosis H37Ra ATCC 25177 and H37Rv ATCC 27294 strains were 0.2 µg/mL and 0.7 µg/mL, respectively. More than 95% of 100 drug-sensitive and 50 drug-resistant mycobacterial clinical isolates were inhibited by extracted S-ACA at 1.0 µg/mL. All of the remaining isolates were inhibited at 2.0 µg/mL. In contrast to the S-enantiomer, synthetic racemic 1'-R,S-ACA (rac-ACA) showed MICs of 0.5 µg/mL and 2.7 µg/mL for M. tuberculosis H37Ra ATCC 25177 and H37Rv ATCC 27294, respectively, suggesting that the anti-tuberculosis effect might be primarily due to the S-form. These observations were in line with the MICs of rac-ACA against 98% of 93 drug-resistant clinical isolates, which showed the effective inhibitory dose at 2.0 µg/mL. After exposure to 2.7 µg/mL of rac-ACA for at least 3 h, the tubercle bacilli were completely killed. These demonstrated that ACA had potent anti-TB activity.

Cutaneous Mycobacterium haemophilum infections in immunocompromised patients in a tertiary hospital in Bangkok, Thailand: under-reported/under-recognized infection.

INTRODUCTION: Mycobacterium haemophilum is one of the non-tuberculous mycobacteria (NTM) that can cause cutaneous infection. As acid-fast staining cannot distinguish NTM from Mycobacterium tuberculosis, and as skin culture for M. haemophilum is not performed routinely, the diagnosis of M. haemophilum infection in Thailand is rarely made. CASE PRESENTATION: Between 2006 and 2009, five patients with M. haemophilum infection were diagnosed in Ramathibodi Hospital, a tertiary care centre in Bangkok, Thailand. The patients were aged 3, 29, 47, 75 and 76 years, and four were immunocompromised. Three patients received immunosuppressive medication. Most patients presented with subacute cutaneous infection. A suboptimal response to conventional antibiotics raised suspicions of M. haemophilum cutaneous infections, which can occur in immunocompromised patients. Diagnoses of these cases were made by skin culture for mycobacteria at an incubating temperature of around 30 °C with iron supplementation, DNA sequencing, or PCR/restriction enzyme analysis. Rifampicin, ofloxacin and clarithromycin were active against all isolates, whereas ethambutol and streptomycin were inactive. CONCLUSION: Skin culture should be performed under special conditions or molecular technique should be used to identify M. haemophilum in susceptible patients.

Antimycobacterial activity of bisbenzylisoquinoline alkaloids from Tiliacora triandra against multidrug-resistant isolates of Mycobacterium tuberculosis.

Bisbenzylisoquinoline alkaloids, tiliacorinine (1), 2'-nortiliacorinine (2), and tiliacorine (3), isolated from the edible plant, Tiliacora triandra, as well as a synthetic derivative, 13'-bromo-tiliacorinine (4), were tested against 59 clinical isolates of multidrug-resistant Mycobacterium tuberculosis (MDR-MTB). The alkaloids 1-4 showed MIC values ranging from 0.7 to 6.2 µg/ml, but they exhibited the MIC value at 3.1 µg/ml against most MDR-MTB isolates. The present work suggests that bisbenzylisoquinoline alkaloids are potential new chemical scaffolds for antimycobacterial activity.

Isoxazole analogs of curcuminoids with highly potent multidrug-resistant antimycobacterial activity.

Curcumin (1), demethoxycurcumin (2) and bisdemethoxycurcumin (3), the curcuminoid constituents of the medicinal plant Curcuma longa L., have been structurally modified to 55 analogs and antimycobacterial activity against Mycobacterium tuberculosis has been evaluated. Among the highly active curcuminoids, the isoxazole analogs are the most active group, with mono-O-methylcurcumin isoxazole (53) being the most active compound (MIC 0.09 microg/mL). It was 1131-fold more active than curcumin (1), the parent compound, and was approximately 18 and 2-fold more active than the standard drugs kanamycin and isoniazid, respectively. Compound 53 also exhibited high activity against the multidrug-resistant M. tuberculosis clinical isolates, with the MICs of 0.195-3.125 microg/mL. The structural requirements for a curcuminoid analog to exhibit antimycobacterial activity are the presence of an isoxazole ring and two unsaturated bonds on the heptyl chain. The presence of a suitable para-alkoxyl group on the aromatic ring which is attached in close proximity to the nitrogen function of the isoxazole ring and a free para-hydroxyl group on another aromatic ring enhances the biological activity.