Pemisahan dan pencirian sebatian semulajadi daripada kayu Vitex vestita (Verbenaceae)

Sampel kayu Vitex vestita (Verbenaceae) telah dikutip dari Hutan Simpan Bukit Belata, Hulu Selangor, Selangor. Kajian ini melibatkan penyaringan fitokimia, keaktifan biologi dan pemencilan komponen kimia dalam ekstrak metanol kayu. Penyaringan fitokimia dijalankan bagi menentukan kehadiran alkaloid, flavonoid, triterpena/steroid dan saponin manakala ujian biologi dijalankan bagi menilai ketoksikan ekstrak tersebut menggunakan ujian kematian anak udang (UKAU). Ujian awal fitokimia mendapati hanya sebatian steroid hadir dalam ekstrak manakala UKAU memberi LC > 1000 ppm. Pemisahan komponen kimia 50 ekstrak dilakukan dengan menggunakan kromatografi cecair vakum, kromatografi radial dan lapisan nipis penyediaan. Dua sebatian telah dipencilkan dan dikenalpasti sebagai 3-epi-20-hidroksiekdison dan 2,3,14,20 ,22,25-heksahidroksikolesta-4,6-diena. Struktur kedua-dua sebatian dielusidasi dengan pelbagai kaedah spektroskopi seperti spektroskopi ultralembayung (UL), inframerah (IM), jisim dan resonans magnet nukleus (RMN) serta secara perbandingan data spektrum diperolehi dengan data spektrum kepustakaan

Antibacterial activity of alkaloid extracts from Ochrosia oppositifolia

Ochrosia oppositifolia can be found along the coastline and is locally known as ‘Mempelam pasih’ or ‘Mangga laut’. In this study, the alkaloids from the leaves, stem-bark and roots were extracted and tested for their antibacterial activity. So far, no previous studies have been carried out to determine the antibacterial potential of the extracts. Each extract was tested using disc-diffusion and minimum inhibitory concentration (MIC) methods. The highest inhibitory diameters shown by 10 mg/mL extracts of the leaves and stem-bark against Staphylococcus aureus and the roots against MRSA were 10.0±2.8 and 10.5±2.1 and 14.0±2.8 mm. On the other hand, the MIC values exhibited by the leaf and stem-bark extracts against Bacillus subtilis, Salmonella thyphimurium and Serratia marcescens and the root extract against Vibrio fluvialis were 3.75 and 0.94 and 0.12 mg/mL. This study broadens the bioactivity potential of the plant and the information obtained can be utilized for pharmacological purposes

New chemical constituent from the rhizomes of Johannesteijsmannia altifrons

A new compound namely 2-[(1′E)-3′-hydroxyl-1′-methyl-1′-propen-1′-yl]-6-methoxy-7-[(2′′-methylheptyl)oxy]-5-benzofurancarboxylic acid and three known compounds of β-sitosterol, γ-taraxasterol and stigmasterol were isolated from the n-hexane extracts of the rhizomes and fruits of Johannesteijsmannia altifrons using vacuum liquid, column and radial chromatography. The structures of the isolated compounds were determined by means of 1D and 2D NMR, FT-IR, UV-VIS spectroscopy and mass spectrometry

3-Amino-5-(piperidin-1-yl)thio­phene-2,4-dicarbonitrile

In the title compound, C11H12N4S, the thio­phene ring is roughly planar, with a maximum deviation of 0.012 (1) Å for the S atom, and makes a dihedral angle of 7.89 (8)° with the mean plane of the piperidine ring, which is in a chair conformation. The crystal packing is stabilized by pairs of centrosymmetric inter­molecular N—H⋯N hydrogen bonds, which results in the formation of a step-wise chain parallel to [10]

Chemical constituents of stem bark of shorea faguetiana

A phytochemical investigation on the acetone extract of the stem bark of Shorea faguetiana was conducted. The isolation of the chemical compounds was carried out by different chromatographic techniques and their structures were elucidated by spectroscopic methods including UV, IR, NMR and MS, and also by comparison with the literature. Five oligostilbenes were isolated and identified as (-)-ε-viniferin, (-)-α-viniferin, (-)-laevifonol, (-)-ampelopsin E and (-)-hopeaphenol

Kesan sitotoksik dan aktiviti anti-mrsa ekstrak metanol phyllanthus gracilipes dan phyllanthus columnaris

Satu kajian telah dijalankan untuk menguji kesan sitotoksik dan aktiviti antibakteria ekstrak metanol dari bahagian berbeza tumbuhan Phyllanthus gracilipes dan P. columnaris. Pengekstrakan dilakukan pada suhu bilik dan menggunakan alat-radas Soxhlet untuk menghasilkan 22 ekstrak. Ujian fitokimia ke atas ekstrak Soxhlet menunjukkan kehadiran saponin dalam semua ekstrak manakala steroid terdapat dalam ekstrak semua bahagian P. gracilipes dan 3 daripada ekstrak P. columnaris. Ujian sitotoksik ke atas kultur sel Vero menunjukkan hanya empat ekstrak yang sitotoksik dengan nilai LC50 di bawah 20 μg/mL iaitu ekstrak suhu bilik kulit-batang P. gracilipes, ekstrak Soxhlet kayu-batang dan daun P. gracilipes serta ekstrak suhu bilik kayu-akar P. columnaris. Ekstrak suhu bilik dan Soxhlet kayu-batang P. gracilipes serta semua ekstrak suhu bilik P. columnaris merencat pertumbuhan 13 pencilan Staphylococcus aureus Rintang-Metisillin (MRSA) yang diuji

Antimicrobial activity of consecutive extracts of etlingera brevilabrum

Disc diffusion (DD), minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) assays were used to evaluate the antimicrobial activity of 21 consecutive extracts of different aerial parts of Etlingera brevilabrum against 18 microorganisms that included six Gram-positive [(+)], ten Gram-negative [(-)] bacteria and two fungi. Among the plant parts, the stolon extracts showed numerous activity than the other parts in which they inhibited Gram-positive of Staphylococcus aureus (ethyl acetate extract: diameter of inhibition zone 12.2±0.3 mm, MIC 3.12 mg/mL, MBC 6.25 mg/mL), methicillin resistant S. aureus (MRSA) (ethyl acetate extract: 12.1±0.2 mm, 12.5 mg/mL, 25 mg/mL), S. epidermidis (ethanol extract: 11.4±0.5 mm, 3.12 mg/mL, 3.12 mg/mL), Bacillus thuringiensis (acetone extract: 13.3±0.5 mm, 12.5 mg/mL, 25 mg/mL) and one Gram-negative of Vibrio paraehaemolyticus (water extract: 14.3±0.4 mm, 1.56 mg/mL, 6.25 mg/mL). The highest activity in MIC was shown by the methanol-water (1:1) and water extracts on Gram-negative Aeromonas hydrophila (1.56 mg/mL: leaf water extract) and V. paraehaemolyticus (1.56 mg/mL: methanol-water and water extracts of stolons and leaves and stem water extract)

Cerapan mikroskopi dan analisis sitometri Streptococcus mutans yang ditindakkan dengan ekstrak batang Melastoma malabathricum L.

Streptococcus mutans adalah bakteria yang terawal membentuk karies gigi pada manusia. Tujuan kajian ini adalah menentukan kesan ekstrak aseton batang Melastoma malabathricum terhadap S. mutans melalui cerapan mikroskopik dan pengambilan pewarna pendarfluor. Pengekstrakan bahagian batang M. malabathricum dengan menggunakan pelarut aseton menghasilkan 0.5 gram ekstrak aseton. Aktiviti anti-bakteria yang ditentukan melalui asai sebaran cakera menunjukkan ekstrak batang pada kepekatan 30 mg/mL merencat pertumbuhan bakteria dengan saiz diameter 15 mm. Kesan tindakan ekstrak terhadap S. mutans diperhatikan melalui cerapan mikroskopi menggunakan mikroskop elektron imbasan (SEM) dan mikroskop elektron transmisi (TEM). Hasil daripada cerapan mikroskopik menunjukkan bahawa ekstrak batang senduduk merosakkan bentuk asal sel dengan memecahkan permukaan dan dindingnya serta menyebabkan sitoplasma terkeluar. Asai pengambilan pewarna pendarfluor propidium iodida (PI) ke dalam sel yang dicerap melalui sitometri aliran menunjukkan berlaku kemasukan PI ke dalam sel yang dirawat dengan ekstrak. Pengambilan propidium iodida pada sel terawat mengesahkan berlaku gangguan pada ketelapan struktur membran sel. Berdasarkan pengamatan mikroskopi dan analisis sitometri dapat disimpulkan bahawa ekstrak aseton batang Melastoma malabathricum bertindak sebagai bahan antibakteria melalui kerosakan pada dinding sel serta mengganggu ketelapan struktur membran

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions. © Copyright