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Publications - Bioorganic Chemistry

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Displaying results 1 to 9 of 9.

Publications

Bini Araba, A.; Ur Rehman, N.; Al-Araimi, A.; Al-Hashmi, S.; Al-Shidhani, S.; Csuk, R.; Hussain, H.; Al-Harrasi, A.; Zadjali, F.; New derivatives of 11-keto-β-boswellic acid (KBA) induce apoptosis in breast and prostate cancers cells Nat. Prod. Res. 35, 707-716, (2021) DOI: 10.1080/14786419.2019.1593165

A series of new 11-keto-β-boswellic acid were partially-synthesized by modifying the hydroxyl and carboxylic acid functional groups of ring A. The structures of the new analogs were confirmed by detailed spectral data analysis. Compounds 4, 5 and 9 exhibited potent anti-cancer results against two human tumor cancer cell lines having IC50 value of MCF-7 (breast) and LNCaP (prostate): 123.6, 9.6 and 88.94 μM and 9.6, 44.12 and 12.03 μM, respectively. Additionally, a maximum nuclear fragmentation was observed for 4 (78.44%) in AKBA treated cells after 24 hr followed by 5 and 9 with (74.25 and 66.9% respectively). This study suggests that the presence of hydrazone functionality (4 and 9) has effectively improved the potency of AKBA. Interestingly, compound 5 with a lost carboxylic acid group of ring A showed comparable potent activity. Highly selective AKBA requires further modification to improve its bioavailability and solubility inside the cancer cells.
Publications

Hussain, H.; Nazir, M.; Saleem, M.; Al-Harrasi, A.; Elizbit, .; Green, I. R.; Fruitful decade of fungal metabolites as anti-diabetic agents from 2010 to 2019: emphasis on α-glucosidase inhibitors Phytochem. Rev. 20, 145-179, (2021) DOI: 10.1007/s11101-020-09733-1

AbstractIn recent years the prevalence of diabetes has increased globally and by 2040 the number of diabetic people has been estimated to increase to 642 million. Various classes of drugs are available to treat Type ll diabetes. However, these drugs are associated with certain side effects. α-Glucosidase is an intriquing target enzyme to treat Type II diabetes, and α-glucosidase inhibitors are considered as first-line drugs for Type ll patients. Fungi, in general, produce natural products with some amazing chemical diversity and many fungal metabolites have illustrated a wide range of biological and pharmacological effects. In this review the focus is on describing the α-glucosidase effects and their potential as anti-diabetic agents of various metabolites isolated from fungi.
Publications

Ur Rehman, N.; Halim, S. A.; Khan, M.; Hussain, H.; Yar Khan, H.; Khan, A.; Abbas, G.; Rafiq, K.; Al-Harrasi, A.; Antiproliferative and Carbonic Anhydrase II Inhibitory Potential of Chemical Constituents from Lycium shawii and Aloe vera: Evidence from In Silico Target Fishing and In Vitro Testing Pharmaceuticals 13, 94, (2020) DOI: 10.3390/ph13050094

Lycium shawii Roem. & Schult and resin of Aloe vera (L.) BURM. F. are commonly used in Omani traditional medication against various ailments. Herein, their antiproliferative and antioxidant potential was explored. Bioassay-guided fractionation of the methanol extract of both plants led to the isolation of 14 known compounds, viz., 1–9 from L. shawii and 10–20 from A. vera. Their structures were confirmed by combined spectroscopic techniques including 1D (1H and 13C) and 2D (HMBC, HSQC, COSY) nuclear magnetic resonance (NMR), and electrospray ionization-mass spectrometry (ESI-MS). The cytotoxic potential of isolates was tested against the triple-negative breast cancer cell line (MDA-MB-231). Compound 5 exhibited excellent antiproliferative activity in a range of 31 μM, followed by compounds 1–3, 7, and 12, which depicted IC50 values in the range of 35–60 μM, while 8, 6, and 9 also demonstrated IC50 values >72 μM. Subsequently, in silico target fishing was applied to predict the most potential cellular drug targets of the active compounds, using pharmacophore modeling and inverse molecular docking approach. The extensive in silico analysis suggests that our compounds may target carbonic anhydrase II (CA-II) to exert their anticancer activities. When tested on CA-II, compounds 5 (IC50 = 14.4 µM), 12 (IC50 = 23.3), and 2 (IC50 = 24.4 µM) showed excellent biological activities in vitro. Additionally, the ethyl acetate fraction of both plants showed promising antioxidant activity. Among the isolated compounds, 4 possesses the highest antioxidant (55 μM) activity followed by 14 (241 μM). The results indicated that compound 4 can be a promising candidate for antioxidant drugs, while compound 5 is a potential candidate for anticancer drugs.
Publications

Ur Rehman, N.; Hussain, H.; Khan, H. Y.; Abbas, G.; Hidayatullah, .; Al-Harrasi, A.; A New Anticancer Bisflavan-3-Ol from Boerhavia elegans Chem. Nat. Compd. 56, 235-238, (2020) DOI: 10.1007/s10600-020-02995-3

A new a bisflavan-3-ol, boerhavianane (1), was isolated from Boerhavia elegans L. The structure of the flavanol dimer was elucidated by detailed spectroscopic analysis including 1H, 13C NMR, COSY, HMQC, HMBC, and ESI-MS. Boerhavianane (1) was evaluated for its anticancer activity and demonstrated a significant reduction in the viability of breast cancer cells in a concentration-dependent manner with an IC50 value of 38.48 μg/mL. Moreover, boerhavianane (1) was also screened for DPPH antioxidant activity and acetyl cholinesterase, xanthine oxidase, urease, and α-glucosidase enzyme inhibition activities. Preliminary results showed that it exhibited significant inhibition (81.0 ± 2.0%) against urease enzyme, whereas for DPPH radical scavenging it showed moderate activity (75.0 ± 1.5%).
Publications

Shamraiz, U.; Hussain, H.; Ur Rehman, N.; Al-Shidhani, S.; Saeed, A.; Khan, H. Y.; Khan, A.; Fischer, L.; Csuk, R.; Badshah, A.; Al-Rawahi, A.; Hussain, J.; Al-Harrasi, A.; Synthesis of new boswellic acid derivatives as potential antiproliferative agents Nat. Prod. Res. 34, 1845-1852, (2020) DOI: 10.1080/14786419.2018.1564295

In the current investigation, a series of heterocyclic derivatives of boswellic acids were prepared along with new monomers of 3-O-acetyl-11-keto-β-boswellic acid (AKBA, 1) 11-keto-β-boswellic acid (KBA, 2) and several new bis-AKBA and KBA homodimers and AKBA-KBA heterodimers. The effects of these compounds on the proliferation of different human cancer cell lines, viz., FaDu (pharynx carcinoma), A2780 (ovarian carcinoma), HT29 (colon adenocarcinoma), and A375 (malignant melanoma), have been evaluated. Thus, KBA homodimer 21 effectively inhibited the growth of FaDu, A2780, HT29, and A375 cells with EC50 values below 9 μM. In addition, compounds 7, 8, 11, 12, 15, 16, and 17 also exhibited cytotoxic effects for A2780, HT29, and A375 cancer cells. In particular, the pyrazine analog 8 was highly cytotoxic for A375 cancer cells with an EC50 value of 2.1 μM.
Books and chapters

Abbas, G.; Ali, M.; Hamaed, A.; Al-Sibani, M.; Hussain, H.; Al-Harrasi, A.; Azadirachta indica: the medicinal properties of the global problems-solving tree (Ozturk, M. et al., eds.). 305-316, (2020) ISBN: 9780128223703 DOI: 10.1016/B978-0-12-819541-3.00017-7

The Azadirachta indica, which is commonly known as the neem tree, has gained prominence thanks to its wide spectrum of medicinal properties and its great potential to treat various diseases. In 1992 the US National Academy of Sciences recognized the importance of this plant and declared neem as a tree for solving global problems. The A. indica belongs to the family Meliaceae. It is a fast growing tropical evergreen tree indigenous to the Indo-Pakistan subcontinent since antiquity. The A. indica is also known as a wonder tree due to its richness in bioactive components in all parts of the tree such as the leaves, the bark, the flowers, the fruits, the seeds, the roots, and the gum oil and therefore it is highly exploitable. Over the years, a large number of diverse types of chemical constituents belonging to the various classes of compounds such as flavonoids, alkaloids, triterpenoids, steroids, carotenoids, and ketones, as well as phenolic compounds, have been extracted from the neem plant. The ultimate goal is to promote plant-derived products with the least side effects as modern drugs. In the last few decades, apart from the chemical analysis of the neem compounds, many researchers have investigated the potential of natural products as candidate medications for the treatment of various diseases. As a summary, substantial progress has been made in identifying neem-derived bioactive compounds for the development of medications for the treatment of a wide range of diseases. In this chapter, the major bioactive components of A. indica are presented along with their applications for the cure of many life-threatening diseases.
Publications

Rehman, N. U.; Khan, A.; Al-Harrasi, A.; Khiat, M.; Hussain, H.; Wadood, A.; Riaz, M.; Natural urease inhibitors from Aloe vera resin and Lycium shawii and their structural-activity relationship and molecular docking study Bioorg. Chem. 88, 102955, (2019) DOI: 10.1016/j.bioorg.2019.102955

Bio-assay guided fractionation of the methanolic extract of Aloe vera resin and Lycium shawii stem successively afforded twenty three compounds; fourteen (1–14) from A. vera and nine (15–23) from L. shawii. All these compounds were characterized by 1D and 2D NMR spectroscopic techniques viz., 1H, 13C, DEPT, HSQC, HMBC, and COSY, and NEOSY, ESI-MS and compared with the reported literature. These compounds were assessed for their potential as urease inhibitors targeted in peptic ulcer. Among crude extracts and fractions of A. vera resin, n-butanol fraction (23.5 ± 1.7 μg·mL−1) showed the most potent urease inhibition followed by methanol (30.9 ± 0.3 μg/mL) and ethyl acetate (31.7 ± 0.5 μg·mL−1). In case of L. shawii, ethyl acetate fraction exhibited the highest urease activity (41.0 ± 1.4 μg/mL) trailed by dichloromethane (55.2 ± 1.5 μg/mL) fraction. Among the isolates, compounds 7, 11 and 23 were found to be excellent urease inhibitors with IC50 values of 14.5 ± 0.90 µM, (16.7 ± 0.16 µM) and 14.0 ± 0.8 µM, respectively. To the best of our knowledge, this is the first report on the urease enzyme inhibitory activity of the said compounds excluding compound 18. In addition, the urease activity of different fractions of L. shawii stem was also reported for the first time. The molecular docking studies showed that all the active compounds well accommodate in the active site of the urease enzyme by interacting with key amino acids.
Publications

Rehman, N. U.; Hussain, H.; Ali, L.; Khan, A.; Mabood, F.; Shinwari, Z. K.; Hussain, J.; Al-Harrasi, A.; Chemical Constituents of Acridocarpus orientalis and Their Chemotaxonomic Significance Chem. Nat. Compd. 55, 586-588, (2019) DOI: 10.1007/s10600-019-02752-1

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Publications

Shamraiz, U.; Raza, B.; Hussain, H.; Badshah, A.; Green, I. R.; Kiani, F. A.; Al-Harrasi, A.; Gold nanotubes and nanorings: promising candidates for multidisciplinary fields Int. Mater. Rev. 64, 478-512, (2019) DOI: 10.1080/09506608.2018.1554991

Gold is considered as an inert metal and ranks as one of the noblest among all the metals. Progressive importance associated with nanotechnology offers potential development of new methods and controlled morphologies of the anisotropic gold nanostructures to develop its innovative properties and commensurate applications. The unique gold nanostructures are considered for their potential applications in various fields due to their large surface area, excellent adhesion properties and resistance to corrosion. In this review, we will present recent developments for gold nanorings and nanotubes, under the headings of synthesis, properties and potential applications in various fields.
  • Die Leibniz-Gemeinschaft
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