Swati P. Joshi

Recent development of plant products with anti- glycation activity: a review

Diabetes mellitus (DM) is an endocrine disorder characterized by chronic hyperglycemia, which results from an absolute or a relative deficiency of insulin or resistance to insulin. Hyperglycemia is increasingly linked to the pathogenesis of diabetic complications in individuals with long-duration diabetes. One of the inevitable consequences of hyperglycemia is the enhanced accumulation of advanced glycation end-products (AGEs), which are implicated in the pathogenesis of diabetes. Various natural products and their active constituents have reportedly been used for the treatment of diabetes and its complications. Some of these molecules are known to have anti-glycation activity. The search for novel anti-glycation agents from various sources is gaining a lot of importance. Attention has especially been focused on plants with an ethnopharmacological background and also on plants rich in triterpenoids and phenolics, which generally exhibit antioxidant and anti-glycation effects. Plant extracts or compounds obtained from them that possess both antioxidant and anti-glycation activities might have great therapeutic potential for treating diabetic complications. This review highlights the anti-glycation activities of phytochemicals, which will aid in the identification of lead molecules for the development of new anti-glycation drugs.

Sesquiterpenoids and phenolics from Crepis mollis

From the roots of Crepis mollis, one new and two known guaianolides were isolated together with eight known guaianolide glycosides, one known germacranolide glycoside and two known phenylpropanoids. The structure and relative configuration of the new compound were established as 9alpha-hydroxy-4beta, 15, 11beta, 13-tetrahydro-dehydrozaluzanin C by spectral methods.

Antimycobacterial Labdane Diterpenes from Leucas stelligera

Phytochemical investigation of the acetone extract of the aerial parts of Leucas stelligera afforded four new compounds (1-4) belonging to the labdane diterpene series as well as two known flavones, velutin (5) and chrysoeriol (6). Structure elucidation of the new compounds was carried out using 1D and 2D NMR spectroscopic data and single-crystal X-ray crystallography of compound 1. Compounds 1-4 exhibited selective antimycobacterial activity against Mycobacterium tuberculosis with IC50 values in the range 5.02-9.80 μg/mL.

Antifungal dimeric chalcone derivative kamalachalcone E from Mallotus philippinensis.

From the red coloured extract (Kamala) prepared through acetone extraction of the fresh whole uncrushed fruits of Mallotus philippinensis, one new dimeric chalcone (1) along with three known compounds 1-(5,7-dihydroxy-2,2,6-trimethyl-2H-1-benzopyran-8-yl)-3-phenyl-2-propen-1-one (2), rottlerin (3) and 4′-hydroxyrottlerin (4) were isolated. The structure of compound 1 was elucidated by 1D and 2D NMR analyses that included HSQC, HMBC, COSY and ROESY experiments along with the literature comparison. Compounds 1–4 were evaluated for antifungal activity against different human pathogenic yeasts and filamentous fungi. The antiproliferative activity of the compounds was evaluated against Thp-1 cell lines. Compounds 1 and 2 both exhibited IC50 of 8, 4 and 16 μg/mL against Cryptococcus neoformans PRL518, C. neoformans ATCC32045 and Aspergillus fumigatus, respectively. Compound 4, at 100 μg/mL, showed 54% growth inhibition of Thp-1 cell lines.

New dipyranocoumarin from the leaves of Calophyllum apetalum Willd

A new dipyranocoumarin, α-hydroxytomentolide A (1) was isolated from the leaves of Calophyllum apetalum together with the known compounds friedelin (2), apetalactone (3), inophyllum C (4) and canophyllol (5). The structure of the new compound was established by spectroscopic studies which include 1H NMR, 13C NMR, NOESY, HetCOSY, COLOC experiments and single crystal X-ray diffraction analysis.

Antimicrobial activity of plant extracts against sexually transmitted pathogens

Comprehensive management of sexually transmitted infections (STIs) using vaginal or rectal microbicide-based intervention is one of the strategies for prevention of HIV infection. Herbal products have been used for treating STIs traditionally. Herein, we present in vitro activity of 10 plant extracts and their 34 fractions against three sexually transmitted/reproductive tract pathogens – Neisseria gonorrhoeae, Haemophilus ducreyi and Candida albicans. The plant parts were selected; the extracts/fractions were prepared and screened by disc diffusion method. The minimum inhibitory and minimum cidal concentrations were determined. The qualitative phytochemical analysis of selected extracts/fractions showing activity was performed. Of the extracts/fractions tested, three inhibited C. albicans, ten inhibited N. gonorrhoeae and five inhibited H. ducreyi growth. Our study demonstrated that Terminalia paniculata Roth. extracts/fractions inhibited growth of all three organisms. The ethyl acetate fraction of Syzygium cumini Linn. and Bridelia retusa (L.) Spreng. extracts was found to inhibit N. gonorrhoeae at lowest concentrations.

New 2,2-diphenylpropane and ethoxylated aromatic monoterpenes from Lavandula gibsoni (Lamiaceae)

A new substituted 2,2-diphenylpropane (1) and two new ethoxylated aromatic monoterpene alcohols (2 and 4) have been isolated from the acetone extract of the aerial parts of Lavandula gibsoni, along with the known compounds 8-hydroxycarvacrol (3), 8-hydroxythymol (5), coumarin (6), 4-methylresorcinol (7), 7,4′-dimethylapigenin (8), salvigenin (9), β-sitosteryl-3-O-β-D-glucopyranosyl-6′-O-palmitate (10) and euscaphic acid D (11). The structures of the isolated compounds were assigned on the basis of their 1H- and 13C-NMR spectra and two-dimensional NMR techniques, which included COSY, HSQC, HMBC and NOESY experiments and comparison with the reported literature.

A new butenolide cinnamate and other biological active chemical constituents from Polygonum glabrum

Phytochemical investigation of the methanol extract of the aerial parts of Polygonum glabrum afforded one new natural product ( − )-2-methoxy-2-butenolide-3-cinnamate (1) along with six known compounds, β-hydroxyfriedalanol (2), 3-hydroxy-5-methoxystilbene (3), ( − ) pinocembrin (4), sitosterol-(6′-O-palmitoyl)-3-O-β-d-glucopyranoside (5), ( − ) pinocembrin-5-methyl ether (6) and sitosterol-3-O-β-d-glucopyranoside (7). Compound 1 showed promising in vitro anti-HIV-1 activity against primary isolates HIV-1UG070 (X4, subtype D) and HIV-1VB59 (R5, subtype C) assayed using TZM-bl cell line with IC50 in the range of 15.68–22.43 μg/mL. The extract showed TI in the range of 19.19–27.37 with IC50 in the range of 10.90–15.55 μg/mL. Compounds 1, 3 and 4 exhibited in vitro anti-mycobacterium activity against Mycobacterium tuberculosis H37Ra with IC50 values of 1.43, 3.33 and 1.11 μg/mL in dormant phase and 2.27, 3.33 and 1.21 μg/mL in active phase, respectively. Compound 4 was found to be the most active antiproliferative with IC50 values of 1.88–11.00 μg/mL against THP-1, A549, Panc-1, HeLa and MCF7 cell lines.

Phyllocladane diterpenes from Anisomeles heyneana

New phyllocladane diterpene, phyllocladan-16α,17-dihydroxy-19-oic acid (1), together with known phyllocladane diterpene, phyllocladan-16α,19-diol (2), cembrane diterpene ovatodiolide (3), sitosteryl-3-O-β-d-glucoside (4), and verbascoside (5), were isolated from aerial parts of Anisomeles heyneana. The structure of compound 1 was elucidated by 1D and 2D NMR analyses which included HSQC, HMBC, and nuclear overhauser effect spectroscopy (NOESY) experiments as well as X-ray crystallography. This is the first report of phyllocladane diterpenes from genus Anisomeles. Compounds 1, 3, 4, and 5 were evaluated for inhibition of Mycobacterium tuberculosis and 3 was found to exhibit anti-mycobacterial activity with IC90 6.53 μg/ml. Compounds 1, 3, and 5, at 100 μg/ml, were also evaluated for inhibition of Thp-1 cell lines, and compounds 1 and 3 showed 59.02% and 96.4% inhibitions, respectively.

Acetone and methanol fruit extracts of Terminalia paniculata inhibit HIV-1 infection in vitro

Abstract In this study, we report the in vitro anti-HIV1 activity of acetone and methanol extracts of fruit of Terminalia paniculata. Cytotoxicity tests were conducted on TZM-bl cells and peripheral blood mononuclear cells (PBMC), the CC50 values of both the extracts were ≥260 μg/mL. Using TZM-bl cells, the extracts were tested for their ability to inhibit replication of two primary isolates HIV-1 (X4, Subtype D) and HIV-1 (R5, Subtype C). The activity against HIV-1 primary isolate (R5, Subtype C) was confirmed using activated PBMC and by quantification of HIV-1 p24 antigen. Both the extracts showed anti-HIV1 activity in a dose-dependent manner. The EC50 values of the acetone and methanol extracts of T. paniculata were ≤10.3 μg/mL. The enzymatic assays were performed to determine the mechanism of action which indicated that the anti-HIV1 activity might be due to inhibition of reverse transcriptase (≥77.7% inhibition) and protease (≥69.9% inhibition) enzymes.