Background and Objective: Kalanchoe tomentosa is identified and their different characteristics regarding the antibacterial and antioxidant properties have a vast effect. Fresh K. tomentosa leaves obtained from Bandung, Indonesia was extracted using n-hexane followed by serial dichloromethane maceration. Materials and Methods: N-hexane and ethyl acetate were used to separate the dichloromethane extract using vacuum liquid chromatography and the isolated compounds were recrystallized with n-hexane. Results: About 37 mg of dichloromethane extract was obtained from the extraction process. Recrystallized compound isolates were identified as stigmast-5-en-3-ol or $-sitosterol. Both dichloromethane extract and $-sitosterol isolated compounds showed strong bacteriostatic activity against S. aureus with MIC = 15.63 and 7.81 µg mLG 1 and K. pneumonia with MIC = 7.81 and 31.25 µg mLG 1 , respectively. However, only dichloromethane extract exhibited a bactericidal effect (7.81 µg mLG 1 ). Conclusion: The pure $-sitosterol compound was isolated from K. tomentosa dichloromethane extract. Both the dichloromethane extract and the isolated $-sitosterol compound had antibacterial effects against S. aureus and K. pneumonia.

Diabetes mellitus (DM) is one of the major health problems. One way to deal with diabetes mellitus is by inhibiting the work of enzymes that hydrolyze carbohydrates, thereby reducing glucose absorption. The enzyme that plays a role in the breakdown of starch into simple sugars is the α-amylase. The genus Kalanchoe or Panda plant has been widely reported to contain a variety of secondary metabolites that have several activities such as antimalarial, antibacterial, antidiabetic, and anticancer potential. This study aims to isolate, determine the chemical structure, and test the inhibitory activity of α-amylase from the ethyl acetate fraction of K. tomentosa leaves. The isolation stage began with the maceration process with n-hexane and fractionated with ethyl acetate. Ethyl acetate extract was refracted using a gradient liquid vacuum chromatography (KCV) method (n-hexane: ethyl acetate: methanol). Repeated gravity columns separated the fraction of KCV results and preparative thin-layer chromatography (TLC-P) to obtain isolate pure. Isolate pure was characterized using several spectroscopic methods, including UV-Vis, IR, NMR. Determination of the structure of the compound against isolate pure shows that this isolate is a 3,7,4’-trihydroxyflavonol or kaempferol compound. The results of the test activity of 3,7,4’-trihydroxyflavonol compounds in inhibiting the enzyme α-amylase in vitro showed an IC50 value of 346 µU/mL. The results obtained indicate that the IC50 value is higher than that of the Acarbose, which was 39.3 µU/mL.

<p>Plak adalah pembentukan komunitas bakteri yang terorganisir pada permukaan gigi yang berupa lapisan tipis tidak berwarna. Pseudomonas aeruginosa adalah salah satu bakteri yang sangat berperan pada pembentukan plak. Metabolit sekunder yang terkandung dalam tanaman Kalanchoe tomentosa dapat digunakan sebagai antibakteri. Tahapan penelitian diawali dengan maserasi menggunakan pelarut n-heksan dan diklorometana. Ekstrak diklorometana dipisahkan menggunakan Kromatografi Cair Vakum (KCV) dengan n-heksana dan etil asetat sebagai pelarut bergradien selanjutnya direkristalisasi dengan n-heksan, hasil rekristalisasi didapatkan isolat 1. Isolat 1 dikarakterisasi dengan spektroskopi infra-red (IR), ultraviolet (UV) dan nuclear magnetic resonance hydrogen (¹H NMR) serta dibandingkan dengan literatur. Isolat 1 diketahui merupakan stigmast-5-en-3ꞵ-ol atau ꞵ-sitosterol. Pada ekstrak diklorometana dan senyawa ꞵ-sitosterol kemudian ditentukan aktivitas antibakteri secara mikrodilusi didapatkan hasil bahwa ekstrak diklorometana dan senyawa ꞵ-sitosterol bukan hanya menunjukan sifat bakteriostatik tetapi juga bakterisid kuat terhadap bakteri Pseudomonas aeruginosadengan nilai Konsentrasi Hambat Minimum (KHM) &lt;100 µg/mL.</p><p><strong>Steroid Compounds from Cocor Bebek (Kalanchoe tomentosa) as Antibacterial Pseudomonas aeruginosa. </strong>Plaque is a thin, colorless layer that adheres tightly to the surface of the teeth and contains a collection of bacteria. One of the bacteria that can form dental plaque is Porphyromonas aeruginosa. Kalanchoe tomentosa contain secondary metabolite which can be used as antibacterial. Stages of the study begin with maceration using n-hexane and dichloromethane. Dichloromethane extract was separated using Vacuum Liquid Chromatography (KCV) using n-hexane and ethyl acetate solvents and then recrystallized with n-hexane, the recrystallization results were obtained by isolate 1. Isolate 1 was marked by IR spectroscopy, and ¹HNMR and compared with literature. Isolate 1 is known as stigmast-5-en-3ꞵ-ol or ꞵ-sitosterol. In dichloromethane extracts and ꞵ-sitosterol is determined by microdilution by microdilution. The results showed that dichloromethane extract and ꞵ-sitosterol compound not only showed strong bacteriostatic but also bacterisid activity against P. aeruginosa with Minimum Inhibiroty Concentration (MIC) &lt;100 μg / mL.</p>