Farediah Ahmad

The chemical composition of essential oils obtained from two parts of Piper magnibaccum C.DC. were analyzed by gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). 25 components representing 93.5% of the essential oil were characterized from the leaf of P. magnibaccum. The essential oil was dominated by germacrene D (40.8%), β-caryophyllene (8.5%) and α-cadinol (6.1%). A total of 33 components, representing 87.6% of the total oil were identified from the stem of P. magnibaccum. The major constituents were β-caryophyllene (19.7%), germacrene D (10.7%), and α- cadinol (8.2%). The antioxidant potential of the leaf and stem essential oils of P. magnibaccum were determined on the basis of phenolic content and scavenging activity of the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC₅₀ 20.5, 17.5 μg/mL) and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) (IC₅₀ 11.7, 12.9 μg/ mL) free radicals. Antityrosinase activity of the leaf and stem were also screened using mushroom tyrosinase assay (I %= 49.50±0.6, 57.01±0.8). The essential oil of P. magnibaccum leaf showed a moderate antibacterial activity with MIC value of 250 μg/mL against P. aeruginosa. None of the essential oils exhibited acute cytotoxicity against MCF-7 and A-549 cells proliferation.

Garcinia prainiana yapraklarını konu alan fitokimyasal araştırmalar sonucunda triterpen yapısında beş bileşik izole edilmiştir; skualen 1, friedelin 2, lupeol 3, 3β-hidroksiöfa- 5,22-dien 4, and 3β-asetoksiöfa-5,22-dien 5. İzole edilen bileşiklerin yapıları spektroskopik yöntemler kullanılarak aydınlatılmış ve elde edilen sonuçlar yukarıda belirtilen bileşiklere ait spektroskopik verilerle karşılaştırılmıştır. Tüm bileşiklerin, H1299 ve A549 akciğer kanseri hücre hatları üzerindeki sitotoksik etkileri MTT yöntemiyle çalışılmıştır. 3β-Asetoksiöfa-5,22-dien 5, H1299 ve A549 hücre hatlarına karşı sırasıyla IC50 = 18.0 μg/ml ve IC50= 36.3 μg/ml derişimde etki göstererek serisindeki en etkili bileşik olarak öne çıkmıştır.

The extracts of the leaves and bark of five Cinnamomum species (C. altissimum, C. griffithii, C. javanicum, C. macrocarpum, and C. velutinum) were screened to evaluate their antioxidant, anticholinesterase, and antityrosinase activities. The bark of C. altissimum showed the highest phenolic content (130.1 mg GA/g), free radical scavenging by DPPH (IC50 126.2 ?g/mL) and ferric reducing antioxidant power (FRAP) assays (341.2 mg AA/g). All of the extracts inhibited linoleic acid peroxidation by greater than 70%, with the leaves of C. altissimum exhibiting the highest inhibition of 87.7%. The leaves of C. javanicum revealed the highest inhibition on anticholinesterase (AChE 30.8%) and butyrylcholinesterase (BChE 46.8%) enzymes. The leaves and bark of C. altissimum and C. velutinum exhibited greater than 20% tyrosinase inhibition, with the leaves of C. altissimum having the highest percentage of inhibition (34.6%). These bioactivities indicate that some Cinnamomum species have therapeutic potential in medicinal research and development of new drugs candidates.Dhaka Univ. J. Pharm. Sci. 14(2): 125-132, 2015 (December)

A Review on Chemical Constituents and Biological Activities of the Genus Beilschmiedia (Lauraceae)

Summary: This study was designed to examine the chemical compositions of the essential oils from three Beilschmiedia species and antioxidant, antimicrobial, antityrosinase, acetylcholinesterase and anti‐inflammatory activities. The essential oils of B. kunstleri, B. maingayi, B. penangiana gave β‐caryophyllene (10.6–12.1%), β‐eudesmol (17.5–24.1%) and δ‐cadinene (17.5–28.7%) as the most abundant components respectively. The bark oil of B. maingayi showed the highest activity in β‐carotene/linoleic acid (125.9%) and phenolic content (288.2 mg GA g⁻¹), while B. penangiana bark oil was found to have strong activity in DPPH (IC₅₀ 84.7 μg mL⁻¹) and ABTS (IC₅₀ 108.3 μg mL⁻¹). The essential oils of B. penangiana showed the best activity against Candida glabrata with MIC value 31.3 μg mL⁻¹. The bark oil of B. penangiana gave 82.5% tyrosinase inhibiton. The leaf oil of B. maingayi gave the highest inhibition in AChE (66.6%) and lipoxygenase (77.0%) assay. Our findings demonstrate that the essential oils have great potential for applications in pharmaceutical and food industries.

Purpose: The aim of this study was to investigate acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and antityrosinase activities of extracts from ten Piper species namely; P. caninum, P. lanatum, P. abbreviatum, P. aborescens, P. porphyrophyllum, P. erecticaule, P. ribesioides, P. miniatum, P. stylosum, and P. majusculum.

The essential oil isolated by hydrodistillation from fresh whole plant parts of Piper muricatum Blume (Piperaceae) was analyzed by GC and GC-MS. Forty components were identified, representing 90.8 % of the total oil. The major components were aromadendrene (16.2 %), β-caryophyllene (8.8 %), germacrene D (7.9 %), γ-cadinene (7.9 %), elemol (5.4 %), γ-elemene (4.9 %) and bicyclogermacrene (4.4 %). The antimicrobial evaluation revealed that the essential oil had moderate activity towards Gram positive bacteria, Bacillus cereus and Streptococcus mutans each with MIC value of 250 µg/mL.

The present study aimed to examine the chemical compositions of the essential oils of Beilschmiedia madang and their antioxidant, antibacterial, antifungal, anticholinesterase and anti-tyrosinase activities. The major constituents of the essential oils of leaf and bark of B. madang were δ-cadinene (17.0 and 20.5 %), β-caryophyllene (10.3 and 6.7 %), α-cubebene (11.3 and 15.6 %), and α-cadinol (5.8 and 10.6 %). The essential oils were screened for their antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, β-carotene/linoleic acid bleaching, and total phenolic content. The bark oil showed the highest β-carotene/linoleic acid bleaching (90.3 % ± 0.2) and DPPH radical scavenging (IC₅₀ 212.0 µg/mL), while the highest phenolic content was exhibited by the leaf oil (94.5 % ± 0.3 mg GA/g). The antibacterial and antifungal activities were investigated by the disc diffusion and micro dilution method. The leaf and bark oils showed moderate activity towards Bacillus subtilis and Staphylococcus aureus with minimum inhibitory concentration (MIC) value 125 µg/mL. For antifungal assay, the bark oil showed strong activity towards Aspergillus niger and Aspergillus fumigatus with MIC value 62.5 µg/mL. Anticholinesterase and anti-tyrosinase activities were evaluated against Ellman method and mushroom tyrosinase, respectively. The results showed that leaf oil gave significant percentage inhibition (I%: acetylcholinesterase 55.2 %, butyrylcholinesterase 60.4 %, tyrosinase 53.1 %).

Natural flavonoids, 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone were synthesised via their respective chalcone. The initial step wasto synthesise derivatives of 2-hydroxyacetophenone and benzaldehyde by protecting the phenolic hydroxyl groups. The chalcone was synthesised byClaisen-Schmidt condensation. Acid hydrolysis and subsequent treatment with sodium acetate of 2’-hydroxy-4,4’-6’-tris(methoxymethyloxy)chalconeand 2’-hydroxy-3,4,4’,6’-tetrakis(methoxymethyloxy)chalcone, gave 4’,5,7-trihydroxyflavanone and 3’,4’,5,7-tetrahydroxyflavanone, respectively.3’,4’,5,7-Tetrahydroxyflavanone was found to be more potent as an antioxidant agent than 4’,5,7-trihydroxyflavanone with 83.11% inhibition and SC508.57 μg/mL in the radical scavenging activity by ESR method.