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Author

Mawardi Rahmani

Bio: Mawardi Rahmani is an academic researcher from Universiti Putra Malaysia. The author has contributed to research in topics: Friedelin & Xanthone. The author has an hindex of 24, co-authored 115 publications receiving 1871 citations.


Papers
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Journal ArticleDOI
TL;DR: Pyranocycloartobiloxanthone A exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, and compound (1) displayed strong activity comparable with the standard kojic acid.
Abstract: One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.

40 citations

Journal ArticleDOI
TL;DR: The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin, together with five other xanthones caloxanthone B, macluraxanthone C, trapezifolixanthone and brasixanthones B, and the steroidal triterpene stigmasterol.
Abstract: The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin (1), together with five other xanthones caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), trapezifolixanthone (5) and brasixanthone B (6) one common triterpene, friedelin (7), and the steroidal triterpene stigmasterol (8). The structures of these compounds were established based on spectral evidence (1D and 2D NMR).

40 citations

Journal ArticleDOI
TL;DR: Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells.
Abstract: Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities. Anti-tumour promoting activity was determined by assaying the capability of this compound to inhibit the expression of early antigen of Epstein-Barr virus (EA-EBV) in Raji cells that was induced by the tumour promoter, phorbol 12-myristate 13-acetate. The concentration of this compound that gave an inhibition rate at fifty percent was 6.0 µg/mL and was not cytotoxic to the cells. Immunoblotting analysis of the expression of EA-EBV showed that girinimbine was able to suppress restricted early antigen (EA-R). However, diffused early antigen (EA-D) was partially suppressed when used at 32.0 µg/mL. Girinimbine exhibited a very strong antioxidant activity as compared to a-tocopherol and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells more than 95%, when treated with the compound at 5.3 and 26.3 µg/mL, respectively. However girinimbine failed to scavenge the stable diphenyl picryl hydrazyl (DPPH)-free radical.

38 citations

Journal Article
TL;DR: In this investigation, triterpenoids friedelin, epifriedelanol and β-sitosterol were isolated from Elaeocarpus floribundus leaves and stem bark and promising antioxidant activity was found.
Abstract: Elaeocarpus floribundus is higher plant that has been used as traditional medicine for treating several diseases. There is no previous report on phytochemicals and bioactivity studies of this species. In this investigation, triterpenoids friedelin, epifriedelanol and β-sitosterol were isolated from its leaves and stem bark. Determination of total phenolic content of methanolic extract of leaves and stem bark was carried out using Folin-Ciocalteu reagent. All extracts and isolated compounds were subjected to screening of antioxidant activity using DPPH free radical scavenging method and cytotoxic activities by MTT assay towards human T4 lymphoblastoid (CEM-SS) and human cervical (HeLa) cancer cells. In the total phenolic content determination, methanolic extract of leaves gave higher value of 503.08±16.71 mg GAE/g DW than stem bark with value of 161.5±24.81 mg GAE/g DW. Polar extracts of leaves and stem bark possessed promising antioxidant activity with methanol extract of stem bark exhibited strongest activity with IC50 value of 7.36±0.01 μg/ml. In the cytotoxic activity assay, only chloroform extract of leaves showed significant activity with IC50 value of 25.6±0.06 μg/ml against CEM-SS cancer cell, while friedelin and epifriedelanol were found to be active against the two cancer cells with IC50 values ranging from 3.54 to 11.45 μg/ml.

37 citations

Journal ArticleDOI
TL;DR: The results demonstrated that the βM induced anti-proliferative effect, leading to G2/M phase cell cycle arrest and apoptosis through both the extrinsic and mitochondrial pathways with the involvement of the multiple pro and anti-apoptosis and NF-kB signalling pathways.

34 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, a compilation of the 13C NMR data of a selected variety of naturally occurring pentacyclic triterpenoids, arranged skeletonwise, is provided.

1,251 citations

Journal ArticleDOI
TL;DR: This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry and is expected to be a comprehensive, authoritative, and critical review of the chal cone template to the chemistry community.
Abstract: Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

800 citations

Journal ArticleDOI
01 May 1949-Nature
TL;DR: The Wealth of India: A Dictionary of Indian Raw Materials and Industrial Products as mentioned in this paper is a dictionary of the economic products of India that was published during the years 1889-99 by the Government of India.
Abstract: IT may occasion some surprise to those men of science who are ill-acquainted with India, and who so frequently express the view that Governments are unappreciative of the importance of science to learn that as far back as 1886 the Government of India arranged for Dr. George (later Sir George) Watt, professor of botany in the Presidency College, Calcutta, to prepare a "Dictionary of the Economic Products of India". The six volumes of this standard work were published during the years 1889-99. In 1908 Sir George Watt published a condensed version, "The Commercial Products of India". Whatever the defects of these 'dictionaries', they have been of inestimable value to all interested in Indian natural products. The Wealth of India A Dictionary of Indian Raw Materials and Industrial Products. Raw Materials, Vol. 1. Pp. xxvii+254+39 plates. 15 rupees ; 24s. Industrial Products, Part 1. Pp. xii+182+8 plates. 8 rupees ; 12s. (New Delhi : Council of Scientific and Industrial Research, 1948.)

694 citations

Journal ArticleDOI
TL;DR: Findings of beneficial properties of GML's extracts and xanthones isolated from this plant so far are summarized.

654 citations